This document summarizes the key components and design process of flat slab construction without slab drops. It provides examples of designing interior and exterior panels of sizes 5x5m, 10x10m, and 15x15m for a 20x20m flat slab without drops. The design process involves determining slab depth, load calculations, moment distribution, and reinforcement sizing. Tables are included that show bending moments and steel areas for column strips and middle strips of the example panels. Interior panels have negative and positive moments in both directions while exterior panels only have negative moments in the column strip and positive moments in the middle strip.
PUNCHING SHEAR RESISTANCE OF FLAT SLABS WITH OPENINGIAEME Publication
There are numbers of methods have been proposed to evaluate the influence from opening on punching shear resistance in flat slabs in the vicinity of columns. In the present paper, the aims are going to compile this state of review on the evaluation of the predicted punching shear strength. A total of 79 tested slabs without shear reinforcement were selected from literature to study the treatments by these methods. The comparisons from their failure loads comparing to their reference specimens without opening shows that the punching shear resistance is inversely proportional to the opening size, location and distance to the face of the related columns.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IRJET- A Technical Approach to Flat Slab Multistorey Building under Wind Spee...IRJET Journal
- The document discusses the technical design of a flat slab multi-storey building under wind speed of 39 m/s.
- It presents the manual design of a G+20 building model using the equivalent frame method, with panels designed for roof, exterior walls, and interior walls.
- The manual design data is then analyzed in STAAD Pro, with shear walls added at two locations to minimize stresses in the building under wind loads.
Optimization of Pre Engineered BuildingsIJERA Editor
Pre-engineered buildings have become quite popular in the last few years. The main advantages are speed of construction and good control over quality. However there is not much information on its economy. There are several parameters like the inclination of the gable, spans, bay spacing, which control the cost of the structure. In the present paper the above parameters are varied systematically and in each case the gable frame designed for the common loads DL, LL, EQ, and WL. The quantity in each case is obtained and finally the structure which regulates the lowest quantity of steel is recommended.
IRJET- Buckling Analysis of Corrugated Hollow Columns using Trapezoidal and S...IRJET Journal
This document presents a numerical study on the buckling behavior of corrugated hollow steel columns under axial loading using trapezoidal and sinusoidal corrugations. Finite element analysis was conducted in ANSYS to analyze rectangular hollow columns with and without ultra high strength steel tubes. Columns with trapezoidal corrugations and ultra high strength tubes exhibited the highest buckling load of 1269.04 kN, indicating greater load carrying capacity compared to other column designs. The study concluded that corrugated columns can carry double the load of conventional columns, are lighter and more efficient due to their hollow structure, and that ultra high strength tubular columns allow for even higher load capacities in a very thin cross-section.
The document discusses the different section assignment options for slabs and walls in ETABS - membrane, shell, and plate. Membrane sections have no out-of-plane stiffness and cannot contribute to resisting bending moments, while plate sections have full out-of-plane stiffness but no in-plane stiffness. Shell sections have both. The effects of each assignment are verified in models of a simple slab. Membrane assignment results in zero slab moments and increased beam moments. Shell and plate assignments produce similar results that account for slab contribution, with lower beam moments. Recommendations are provided on appropriate usage of each section type.
This research introduces a new simple, efficient, and practical procedure to design
the reinforced concrete (RC) circular slabs which have large diameters. The principal
idea of this paper concerns to use the isotropic perpendicular RC straight joists to
resist the external load. The yield-line theory was adapted to analysis the circular
waffle slabs. The steps of design were according to the ACI Code provisions. Fixed
and simply supported circular slabs were presented. Closed form equations have been
driven by author for the purposes of analysis and design this type of slabs by the
present procedure. Uniformly distributed load was considered, that represent almost
practical cases. Useful illustration example is presented in this study according to the
available materials in Iraq to facilitate the job of designers. The good performance of
RC circular slab which design by the present procedure proved clearly the efficiency
of this technique.
IRJET- Cost Analysis of Two-Way Slab and Post Tension SlabIRJET Journal
The document compares the cost of two types of slabs - two-way slabs and post-tension slabs. It designs a 5m x 9.38m panel using both slab types based on Indian code provisions. Material quantities and costs are calculated and compared. The post-tension slab is found to be more economical with lower concrete and steel requirements. Design checks are performed to ensure the slabs meet strength, serviceability, and stress limits.
PUNCHING SHEAR RESISTANCE OF FLAT SLABS WITH OPENINGIAEME Publication
There are numbers of methods have been proposed to evaluate the influence from opening on punching shear resistance in flat slabs in the vicinity of columns. In the present paper, the aims are going to compile this state of review on the evaluation of the predicted punching shear strength. A total of 79 tested slabs without shear reinforcement were selected from literature to study the treatments by these methods. The comparisons from their failure loads comparing to their reference specimens without opening shows that the punching shear resistance is inversely proportional to the opening size, location and distance to the face of the related columns.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IRJET- A Technical Approach to Flat Slab Multistorey Building under Wind Spee...IRJET Journal
- The document discusses the technical design of a flat slab multi-storey building under wind speed of 39 m/s.
- It presents the manual design of a G+20 building model using the equivalent frame method, with panels designed for roof, exterior walls, and interior walls.
- The manual design data is then analyzed in STAAD Pro, with shear walls added at two locations to minimize stresses in the building under wind loads.
Optimization of Pre Engineered BuildingsIJERA Editor
Pre-engineered buildings have become quite popular in the last few years. The main advantages are speed of construction and good control over quality. However there is not much information on its economy. There are several parameters like the inclination of the gable, spans, bay spacing, which control the cost of the structure. In the present paper the above parameters are varied systematically and in each case the gable frame designed for the common loads DL, LL, EQ, and WL. The quantity in each case is obtained and finally the structure which regulates the lowest quantity of steel is recommended.
IRJET- Buckling Analysis of Corrugated Hollow Columns using Trapezoidal and S...IRJET Journal
This document presents a numerical study on the buckling behavior of corrugated hollow steel columns under axial loading using trapezoidal and sinusoidal corrugations. Finite element analysis was conducted in ANSYS to analyze rectangular hollow columns with and without ultra high strength steel tubes. Columns with trapezoidal corrugations and ultra high strength tubes exhibited the highest buckling load of 1269.04 kN, indicating greater load carrying capacity compared to other column designs. The study concluded that corrugated columns can carry double the load of conventional columns, are lighter and more efficient due to their hollow structure, and that ultra high strength tubular columns allow for even higher load capacities in a very thin cross-section.
The document discusses the different section assignment options for slabs and walls in ETABS - membrane, shell, and plate. Membrane sections have no out-of-plane stiffness and cannot contribute to resisting bending moments, while plate sections have full out-of-plane stiffness but no in-plane stiffness. Shell sections have both. The effects of each assignment are verified in models of a simple slab. Membrane assignment results in zero slab moments and increased beam moments. Shell and plate assignments produce similar results that account for slab contribution, with lower beam moments. Recommendations are provided on appropriate usage of each section type.
This research introduces a new simple, efficient, and practical procedure to design
the reinforced concrete (RC) circular slabs which have large diameters. The principal
idea of this paper concerns to use the isotropic perpendicular RC straight joists to
resist the external load. The yield-line theory was adapted to analysis the circular
waffle slabs. The steps of design were according to the ACI Code provisions. Fixed
and simply supported circular slabs were presented. Closed form equations have been
driven by author for the purposes of analysis and design this type of slabs by the
present procedure. Uniformly distributed load was considered, that represent almost
practical cases. Useful illustration example is presented in this study according to the
available materials in Iraq to facilitate the job of designers. The good performance of
RC circular slab which design by the present procedure proved clearly the efficiency
of this technique.
IRJET- Cost Analysis of Two-Way Slab and Post Tension SlabIRJET Journal
The document compares the cost of two types of slabs - two-way slabs and post-tension slabs. It designs a 5m x 9.38m panel using both slab types based on Indian code provisions. Material quantities and costs are calculated and compared. The post-tension slab is found to be more economical with lower concrete and steel requirements. Design checks are performed to ensure the slabs meet strength, serviceability, and stress limits.
IRJET- Behaviour of Cold Form Steel under Point Loading & Statically Defi...IRJET Journal
This document presents an analytical and experimental study on the behavior of cold-formed steel (CFS) channel sections under point loading. Finite element analysis was conducted using ANSYS to analyze CFS channel sections with various stiffener configurations. Experimental testing was also performed on CFS channel sections with and without stiffeners. The results found that CFS channel sections with rectangular stiffeners and lips had the highest load carrying capacity and lowest deformation compared to other section configurations based on both analytical and experimental analysis. In particular, the rectangular stiffened CFS channel section with a 30mm lip was found to have a load carrying capacity of 42.25kN and deformation of 3.06mm from experimental testing.
Analysis of multistoried braced frame subjected to seismic and gravity loading.IJERA Editor
The structure in high seismic areas may be susceptible to the severe damage. Along with gravity load structure has to withstand to lateral load which can develop high stresses. Now-a-days, shear wall in R.C. structure and steel bracings in steel structure are most popular system to resist lateral load due to earthquake, wind, blast etc. bracing is a highly efficient and economical method of resisting horizontal forces in a frame structure. Bracing is efficient because the diagonals work in axial stress and therefore call for minimum member sizes in providing stiffness and strength against horizontal shear. Through the addition of the bracing system, load could be transferred out of the frame and into the braces, by passing the weak columns while increasing strength. In this study Steel Frame is modeled and analyzed three Parts viz., (i) Model without Steel bracing (bare frame), (ii) Model completely Steel braced (fully braced frame), (iii) Model with partially Steel bay wise braced frames. The computer aided analysis is done by using STAAD-PRO to find out the effective lateral load system during earthquake in high seismic areas.
Analysis of Parabolic Shell by Different Models Using Software SAP 2000ijtsrd
The shell structure consists of a thin reinforced concrete shell without the use of internal columns to create an internal opening., parabolic or spherical cross section. On the other hand, warehouses and playgrounds are conventional concrete frame structures, on the other hand, they can be difficult to design as the exact shape required for the stability of the structure depends on the material used, the dimensions of the enclosure, external or internal loads and other chamfers.. .. Thus, by changing the shell parameter, the performance of the shell will also change. The main goal of this work is to parametrically analyze different designs of cylindrical shells of different lengths in order to analyze two different lengths of taken cylindrical shells, and then change two parameters, first the radius and then the thickness, based on the radii. and the difference in thickness for the same width, length and material of the frame, we will evaluate the behavior of the frame for different models. Rohit Sahu | Barun Kumar | A. K. Jha "Analysis of Parabolic Shell by Different Models Using Software: SAP 2000" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46337.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/46337/analysis-of-parabolic-shell-by-different-models-using-software-sap-2000/rohit-sahu
Analysis of multistoried braced steel space frame subjected to gravity and se...IJERA Editor
This document analyzes multistory steel space frames with bracing subjected to gravity and seismic loads. Three models are analyzed: an unbraced frame, a frame with cross bracing, and a frame with single diagonal bracing. Frames ranging from 5 to 11 stories tall and with 3, 5, or 7 bays are modeled and analyzed. Results show that braced frames experience lower displacements and forces than unbraced frames. Cross bracing produces smaller axial forces in braces than single diagonal bracing. Soft stories at intermediate levels perform better than soft stories at the ground level. Partially braced frames with 1 or 2 bays of bracing provide adequate stiffness at a lower cost. Overall, cross bracing is
IRJET- Behavior of Trapezoidal Corrugated Web Steel Built-Up Beam under Point...IRJET Journal
This document summarizes an experimental study that compared the behavior of steel beams with trapezoidal corrugated webs with different corrugation angles (25°, 30°, 35°, 45°, 60°) under point load conditions. Five steel beam specimens were fabricated and tested. The results showed that the beam with a 35° corrugation angle experienced 21-82% less central deflection and 31-104% less lateral displacement compared to the other beams, indicating it provided the optimal combination of strength and material efficiency. Therefore, a trapezoidal corrugated web with a 35° corrugation angle can result in improved structural behavior for steel beams.
Dr. B. Rajeevan gave a lecture on design for flexure in reinforced concrete structures. The key points covered included:
- Type II design problems involve determining cross-sectional dimensions and reinforcement area where no unique solution exists.
- Requirements for flexural reinforcement include nominal cover, clear cover, and effective cover to protect concrete.
- Spacing of reinforcing bars is limited to a minimum for constructability and a maximum to control cracking and ensure bond.
- Design of singly and doubly reinforced beams was demonstrated through examples, determining reinforcement areas based on flexural strength requirements.
- Design of flanged beams like T-beams and L-beams was discussed, highlighting differences in reinforcement
IRJET- Seismic Analysis of Eccentrically and Concentrically Steel Braced Stee...IRJET Journal
- The document analyzes the seismic performance of eccentrically and concentrically steel braced steel structures through equivalent static analysis in STAAD.Pro.
- Results show that braced structures perform better than unbraced structures, with braced structures experiencing lower lateral displacement and storey drift. Cross braced and concentrically braced frames performed the best with least displacement.
- Braced structures are more effective at resisting seismic loads and dissipating seismic energy compared to unbraced structures. The use of bracing systems improves the lateral stiffness and capacity of steel structures.
This document provides the design of a rectangular water tank with a capacity of 2500 cubic meters. It includes:
1) Design of the roof slab as a flat slab with columns spaced 5 meters apart and a thickness of 240mm.
2) Design of columns with a size of 350mm and reinforcement of 6 bars of 16mm diameter.
3) Design of the vertical walls with a thickness of 230mm at the base reducing to 180mm in the middle. Reinforcement of 16mm diameter bars at 125mm centers is provided.
4) Checks for crack width for the columns and walls show the crack width is less than the permissible 0.2mm.
STUDY ON BOND MECHANISM OF PSWC BARS WITH CONCRETEShoaib Wani
PSWC- Plain surface with wave-type configuration, a rebar for durable concrete construction at zero cost addition and much more. The yield strength & the bond strength of HYSD bars > plain round mild steel straight bars. The durability issues related to the use of HYSD bars in RCC & problems of early distress.
Early corrosion due to the provision of surface protrusions in HYSD bars for achieving the higher bond strength.
Alternative solution : A new type of reinforcing steel bar (named as PSWC-bar) with normal plain round surface and deformed axis is proposed.
This document provides an outline for a lecture on the design of concrete structures. It discusses the objectives and methods of analysis and design, including properties of materials and the empirical, elastic, and limit state theories. It also summarizes the modern reinforced concrete structures, objectives of design, loads and forces to consider, methods of analysis, and combinations of loads. Key points covered include flexibility, durability, and moldability of concrete; dead, imposed, wind, snow, and earthquake loads; and the limit state and working stress design methods.
STUDY ON INFLUENCE OF RIB CONFIGURATION ON BOND STRENGTH DEVELOPMENT BETWEEN ...Shoaib Wani
To conduct pull out test as per IS 2770-1967 (Methods of testing bond in reinforced concrete –part 1 pull out test ) to assess the bond strength development between concrete and steel rebar.
Pull-out test was conducted on:
Mild steel bar
HYSD –parallel ribbed bar
HYSD – diamond ribbed bar
IRJET- Seismic Behaviour of Steel Structures with Bracings Having Seismic Irr...IRJET Journal
This document discusses the seismic behavior of steel structures with different bracing systems and irregularities. It analyzes 3D models of 8, 10, and 12 story steel buildings with rectangular and C-shaped plans in zones III, IV, and V, with and without X-bracing and K-bracing systems. The models with vertical irregularities are analyzed for lateral displacement and story drift. Results show story drift increases with zone intensity, number of stories, and vertical irregularity. Bracing systems reduce drift compared to no bracing, with K-bracing having slightly higher drift than X-bracing. Lateral displacement and story drift also increase from lower to higher zones due to increasing seismic intensity.
Study of Buckling Restrained Braces in Steel Frame BuildingIJERA Editor
Conventional braces have limited deformation ductility capacity, and exhibit unsymmetrical hysteretic cycles, with marked strength deterioration when loaded in compression. To overcome the above mentioned problems, a new type of brace was developed in Japan called as buckling restrained braces, designated as BRB’s. These braces are designed such that buckling is inhibited to occur, exhibiting adequate behavior and symmetrical hysteretic curves under the action of both tensile and compressive cycles, produced by the action of seismic and wind forces. This paper presents experimental results concerning the lateral load carrying capacity of steel frame model by use of buckling restrained brace. This paper also includes the comparative study of lateral load carrying capacity of frame model for bare frame, frame with Conventional brace and frame with buckling restrained brace.
The document discusses the design and erection of column base plates. It covers types of base plates for different load cases including axial compression, tension, and combined axial and moment loads. Key topics covered include base plate and anchor rod materials, design for concrete crushing and bending, anchor rod design, and erection procedures. Diagrams illustrate critical sections and design equations for different limit states. Construction tolerances and OSHA standards for base plate design are also summarized.
1. The nominal resisting moment of reinforced concrete beams with compression steel is calculated as the sum of two parts: the moment due to compression concrete and tensile steel, and the moment due to compression steel and tensile steel.
2. The strain in the compression steel is checked to determine if it has yielded, and then the compression stress is calculated.
3. The analysis procedure involves determining the neutral axis location, checking compression steel yield, and calculating section ductility and design moment strength.
The project consists of designing the structural elements of a two-part school building. The first part has three floors and the second part has one floor. The structural system uses a one-way ribbed slab system. Reinforced concrete beams, columns, footings, and shear walls will be designed according to ultimate strength design philosophy and codes including ACI 318 and IBC 2009. The summary provides an overview of the structural layout and design approach.
The document discusses materials used in reinforced concrete structures, including concrete, steel reinforcement, and their properties. It provides three key points:
1) Concrete quality is measured by strength and durability, which depend on water-cement ratio, aggregates, and hydration. Workability and economy are also important considerations in mix design.
2) Steel reinforcement commonly used includes deformed bars and welded wire fabric in various grades depending on the yield strength required.
3) The properties of both concrete and steel, such as stress-strain behavior, modulus of elasticity, creep, and shrinkage, influence the design and performance of reinforced concrete structures.
Paper " STRUT-AND-TIE MODEL AND 3-D NONLINEAR FINITE ELEMENT ANALYSIS FOR THE...Waleed E. El-Demerdash
This document discusses the use of strut-and-tie modeling and 3D nonlinear finite element analysis to predict the behavior of reinforced concrete shallow and deep beams with openings. It presents the development of strut-and-tie models based on experimental results for selected beams. Finite element analysis using ANSYS is also employed for selected beams to complement the strut-and-tie model results. A parametric study investigates factors affecting beam behavior. Comparisons are made between finite element results, strut-and-tie model results, and experimental data.
BEHAVIOR OF SLENDER COLUMN SUBJECTED TO ECCENTRIC LOADINGijiert bestjournal
This paper focuses on Behavior of slender column su bjected to eccentric loading. Six slender,reinforced concrete columns with slenderness ratio equals to 15;the compressive strength of the concrete were ranged from 60 to 100 MPa. Slender co lumn were subjected to eccentric axial load with load-eccentricity:depth ratio of 0.15. Three columns were reinforced with six bars having a nominal strength of 415 MPa and other three were re inforced with same number of bars having strength equals to 500 MPa with longitudinal steel ratio equals to 4%. The test results were compared with the values predicted using IS 456-200 0. These test,enabled the provision for slender columns in the code to be checked against e xperimental values,have indicated that IS 456-2000 are very safe and uneconomical design docu ment for HPC slender column.
Cost Optimization of a Tubular Steel Truss Using Limit State Method of DesignIJERA Editor
Limit state method helps to design structures based on both safety and serviceability. The structures are designed to withstand ultimate loads or the loads at which failure occurs unlike working stress method where only service loads are considered. This leads to enhanced safety. Also unlike the working stress method, the structures are economical. It is also better than ultimate load method as serviceability requirement is also taken care of by considering various safety factors for all the load types and structures do not undergo massive deflection and cracks. For tubular sections, higher strength to weight ratio could result in upto 30% savings in steel .Due to the high torsional rigidity and compressive strength, Tubular sections behave more efficiently than conventional steel section This study is regarding the economy, load carrying capacity of all structural members and their corresponding safety measures.
A Critical Review of Flat Slabs under different parametersIRJET Journal
This document provides a critical review of flat slab design under different parameters. It discusses the types of flat slabs, design considerations like slab thickness and reinforcement, and analyses the behavior of flat slabs under various loads and conditions. The key findings are that flat slab structures can be 15% less expensive than traditional slabs, and are better suited for high-rise buildings due to cost savings, aesthetic benefits, and architectural flexibility. However, flat slabs may experience greater displacements and bending moments than traditional slabs in seismic conditions due to lower lateral stiffness.
IRJET- Behaviour of Cold Form Steel under Point Loading & Statically Defi...IRJET Journal
This document presents an analytical and experimental study on the behavior of cold-formed steel (CFS) channel sections under point loading. Finite element analysis was conducted using ANSYS to analyze CFS channel sections with various stiffener configurations. Experimental testing was also performed on CFS channel sections with and without stiffeners. The results found that CFS channel sections with rectangular stiffeners and lips had the highest load carrying capacity and lowest deformation compared to other section configurations based on both analytical and experimental analysis. In particular, the rectangular stiffened CFS channel section with a 30mm lip was found to have a load carrying capacity of 42.25kN and deformation of 3.06mm from experimental testing.
Analysis of multistoried braced frame subjected to seismic and gravity loading.IJERA Editor
The structure in high seismic areas may be susceptible to the severe damage. Along with gravity load structure has to withstand to lateral load which can develop high stresses. Now-a-days, shear wall in R.C. structure and steel bracings in steel structure are most popular system to resist lateral load due to earthquake, wind, blast etc. bracing is a highly efficient and economical method of resisting horizontal forces in a frame structure. Bracing is efficient because the diagonals work in axial stress and therefore call for minimum member sizes in providing stiffness and strength against horizontal shear. Through the addition of the bracing system, load could be transferred out of the frame and into the braces, by passing the weak columns while increasing strength. In this study Steel Frame is modeled and analyzed three Parts viz., (i) Model without Steel bracing (bare frame), (ii) Model completely Steel braced (fully braced frame), (iii) Model with partially Steel bay wise braced frames. The computer aided analysis is done by using STAAD-PRO to find out the effective lateral load system during earthquake in high seismic areas.
Analysis of Parabolic Shell by Different Models Using Software SAP 2000ijtsrd
The shell structure consists of a thin reinforced concrete shell without the use of internal columns to create an internal opening., parabolic or spherical cross section. On the other hand, warehouses and playgrounds are conventional concrete frame structures, on the other hand, they can be difficult to design as the exact shape required for the stability of the structure depends on the material used, the dimensions of the enclosure, external or internal loads and other chamfers.. .. Thus, by changing the shell parameter, the performance of the shell will also change. The main goal of this work is to parametrically analyze different designs of cylindrical shells of different lengths in order to analyze two different lengths of taken cylindrical shells, and then change two parameters, first the radius and then the thickness, based on the radii. and the difference in thickness for the same width, length and material of the frame, we will evaluate the behavior of the frame for different models. Rohit Sahu | Barun Kumar | A. K. Jha "Analysis of Parabolic Shell by Different Models Using Software: SAP 2000" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46337.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/46337/analysis-of-parabolic-shell-by-different-models-using-software-sap-2000/rohit-sahu
Analysis of multistoried braced steel space frame subjected to gravity and se...IJERA Editor
This document analyzes multistory steel space frames with bracing subjected to gravity and seismic loads. Three models are analyzed: an unbraced frame, a frame with cross bracing, and a frame with single diagonal bracing. Frames ranging from 5 to 11 stories tall and with 3, 5, or 7 bays are modeled and analyzed. Results show that braced frames experience lower displacements and forces than unbraced frames. Cross bracing produces smaller axial forces in braces than single diagonal bracing. Soft stories at intermediate levels perform better than soft stories at the ground level. Partially braced frames with 1 or 2 bays of bracing provide adequate stiffness at a lower cost. Overall, cross bracing is
IRJET- Behavior of Trapezoidal Corrugated Web Steel Built-Up Beam under Point...IRJET Journal
This document summarizes an experimental study that compared the behavior of steel beams with trapezoidal corrugated webs with different corrugation angles (25°, 30°, 35°, 45°, 60°) under point load conditions. Five steel beam specimens were fabricated and tested. The results showed that the beam with a 35° corrugation angle experienced 21-82% less central deflection and 31-104% less lateral displacement compared to the other beams, indicating it provided the optimal combination of strength and material efficiency. Therefore, a trapezoidal corrugated web with a 35° corrugation angle can result in improved structural behavior for steel beams.
Dr. B. Rajeevan gave a lecture on design for flexure in reinforced concrete structures. The key points covered included:
- Type II design problems involve determining cross-sectional dimensions and reinforcement area where no unique solution exists.
- Requirements for flexural reinforcement include nominal cover, clear cover, and effective cover to protect concrete.
- Spacing of reinforcing bars is limited to a minimum for constructability and a maximum to control cracking and ensure bond.
- Design of singly and doubly reinforced beams was demonstrated through examples, determining reinforcement areas based on flexural strength requirements.
- Design of flanged beams like T-beams and L-beams was discussed, highlighting differences in reinforcement
IRJET- Seismic Analysis of Eccentrically and Concentrically Steel Braced Stee...IRJET Journal
- The document analyzes the seismic performance of eccentrically and concentrically steel braced steel structures through equivalent static analysis in STAAD.Pro.
- Results show that braced structures perform better than unbraced structures, with braced structures experiencing lower lateral displacement and storey drift. Cross braced and concentrically braced frames performed the best with least displacement.
- Braced structures are more effective at resisting seismic loads and dissipating seismic energy compared to unbraced structures. The use of bracing systems improves the lateral stiffness and capacity of steel structures.
This document provides the design of a rectangular water tank with a capacity of 2500 cubic meters. It includes:
1) Design of the roof slab as a flat slab with columns spaced 5 meters apart and a thickness of 240mm.
2) Design of columns with a size of 350mm and reinforcement of 6 bars of 16mm diameter.
3) Design of the vertical walls with a thickness of 230mm at the base reducing to 180mm in the middle. Reinforcement of 16mm diameter bars at 125mm centers is provided.
4) Checks for crack width for the columns and walls show the crack width is less than the permissible 0.2mm.
STUDY ON BOND MECHANISM OF PSWC BARS WITH CONCRETEShoaib Wani
PSWC- Plain surface with wave-type configuration, a rebar for durable concrete construction at zero cost addition and much more. The yield strength & the bond strength of HYSD bars > plain round mild steel straight bars. The durability issues related to the use of HYSD bars in RCC & problems of early distress.
Early corrosion due to the provision of surface protrusions in HYSD bars for achieving the higher bond strength.
Alternative solution : A new type of reinforcing steel bar (named as PSWC-bar) with normal plain round surface and deformed axis is proposed.
This document provides an outline for a lecture on the design of concrete structures. It discusses the objectives and methods of analysis and design, including properties of materials and the empirical, elastic, and limit state theories. It also summarizes the modern reinforced concrete structures, objectives of design, loads and forces to consider, methods of analysis, and combinations of loads. Key points covered include flexibility, durability, and moldability of concrete; dead, imposed, wind, snow, and earthquake loads; and the limit state and working stress design methods.
STUDY ON INFLUENCE OF RIB CONFIGURATION ON BOND STRENGTH DEVELOPMENT BETWEEN ...Shoaib Wani
To conduct pull out test as per IS 2770-1967 (Methods of testing bond in reinforced concrete –part 1 pull out test ) to assess the bond strength development between concrete and steel rebar.
Pull-out test was conducted on:
Mild steel bar
HYSD –parallel ribbed bar
HYSD – diamond ribbed bar
IRJET- Seismic Behaviour of Steel Structures with Bracings Having Seismic Irr...IRJET Journal
This document discusses the seismic behavior of steel structures with different bracing systems and irregularities. It analyzes 3D models of 8, 10, and 12 story steel buildings with rectangular and C-shaped plans in zones III, IV, and V, with and without X-bracing and K-bracing systems. The models with vertical irregularities are analyzed for lateral displacement and story drift. Results show story drift increases with zone intensity, number of stories, and vertical irregularity. Bracing systems reduce drift compared to no bracing, with K-bracing having slightly higher drift than X-bracing. Lateral displacement and story drift also increase from lower to higher zones due to increasing seismic intensity.
Study of Buckling Restrained Braces in Steel Frame BuildingIJERA Editor
Conventional braces have limited deformation ductility capacity, and exhibit unsymmetrical hysteretic cycles, with marked strength deterioration when loaded in compression. To overcome the above mentioned problems, a new type of brace was developed in Japan called as buckling restrained braces, designated as BRB’s. These braces are designed such that buckling is inhibited to occur, exhibiting adequate behavior and symmetrical hysteretic curves under the action of both tensile and compressive cycles, produced by the action of seismic and wind forces. This paper presents experimental results concerning the lateral load carrying capacity of steel frame model by use of buckling restrained brace. This paper also includes the comparative study of lateral load carrying capacity of frame model for bare frame, frame with Conventional brace and frame with buckling restrained brace.
The document discusses the design and erection of column base plates. It covers types of base plates for different load cases including axial compression, tension, and combined axial and moment loads. Key topics covered include base plate and anchor rod materials, design for concrete crushing and bending, anchor rod design, and erection procedures. Diagrams illustrate critical sections and design equations for different limit states. Construction tolerances and OSHA standards for base plate design are also summarized.
1. The nominal resisting moment of reinforced concrete beams with compression steel is calculated as the sum of two parts: the moment due to compression concrete and tensile steel, and the moment due to compression steel and tensile steel.
2. The strain in the compression steel is checked to determine if it has yielded, and then the compression stress is calculated.
3. The analysis procedure involves determining the neutral axis location, checking compression steel yield, and calculating section ductility and design moment strength.
The project consists of designing the structural elements of a two-part school building. The first part has three floors and the second part has one floor. The structural system uses a one-way ribbed slab system. Reinforced concrete beams, columns, footings, and shear walls will be designed according to ultimate strength design philosophy and codes including ACI 318 and IBC 2009. The summary provides an overview of the structural layout and design approach.
The document discusses materials used in reinforced concrete structures, including concrete, steel reinforcement, and their properties. It provides three key points:
1) Concrete quality is measured by strength and durability, which depend on water-cement ratio, aggregates, and hydration. Workability and economy are also important considerations in mix design.
2) Steel reinforcement commonly used includes deformed bars and welded wire fabric in various grades depending on the yield strength required.
3) The properties of both concrete and steel, such as stress-strain behavior, modulus of elasticity, creep, and shrinkage, influence the design and performance of reinforced concrete structures.
Paper " STRUT-AND-TIE MODEL AND 3-D NONLINEAR FINITE ELEMENT ANALYSIS FOR THE...Waleed E. El-Demerdash
This document discusses the use of strut-and-tie modeling and 3D nonlinear finite element analysis to predict the behavior of reinforced concrete shallow and deep beams with openings. It presents the development of strut-and-tie models based on experimental results for selected beams. Finite element analysis using ANSYS is also employed for selected beams to complement the strut-and-tie model results. A parametric study investigates factors affecting beam behavior. Comparisons are made between finite element results, strut-and-tie model results, and experimental data.
BEHAVIOR OF SLENDER COLUMN SUBJECTED TO ECCENTRIC LOADINGijiert bestjournal
This paper focuses on Behavior of slender column su bjected to eccentric loading. Six slender,reinforced concrete columns with slenderness ratio equals to 15;the compressive strength of the concrete were ranged from 60 to 100 MPa. Slender co lumn were subjected to eccentric axial load with load-eccentricity:depth ratio of 0.15. Three columns were reinforced with six bars having a nominal strength of 415 MPa and other three were re inforced with same number of bars having strength equals to 500 MPa with longitudinal steel ratio equals to 4%. The test results were compared with the values predicted using IS 456-200 0. These test,enabled the provision for slender columns in the code to be checked against e xperimental values,have indicated that IS 456-2000 are very safe and uneconomical design docu ment for HPC slender column.
Cost Optimization of a Tubular Steel Truss Using Limit State Method of DesignIJERA Editor
Limit state method helps to design structures based on both safety and serviceability. The structures are designed to withstand ultimate loads or the loads at which failure occurs unlike working stress method where only service loads are considered. This leads to enhanced safety. Also unlike the working stress method, the structures are economical. It is also better than ultimate load method as serviceability requirement is also taken care of by considering various safety factors for all the load types and structures do not undergo massive deflection and cracks. For tubular sections, higher strength to weight ratio could result in upto 30% savings in steel .Due to the high torsional rigidity and compressive strength, Tubular sections behave more efficiently than conventional steel section This study is regarding the economy, load carrying capacity of all structural members and their corresponding safety measures.
A Critical Review of Flat Slabs under different parametersIRJET Journal
This document provides a critical review of flat slab design under different parameters. It discusses the types of flat slabs, design considerations like slab thickness and reinforcement, and analyses the behavior of flat slabs under various loads and conditions. The key findings are that flat slab structures can be 15% less expensive than traditional slabs, and are better suited for high-rise buildings due to cost savings, aesthetic benefits, and architectural flexibility. However, flat slabs may experience greater displacements and bending moments than traditional slabs in seismic conditions due to lower lateral stiffness.
This document compares the economical aspects of long span flat slabs and grid slabs. Flat slabs are modeled using the direct design method, while grid slabs are modeled using plate theory. The cost is calculated based on the quantity of steel, concrete volume, and formwork costs. For spans ranging from 5-13 meters, the cost per square meter is determined for different slab designs. The results show that flat slabs are more economical for smaller spans, but grid slabs become more economical for longer spans above 9 meters.
IRJET- Planning, Design and Analysis of G+3 Hospital Building Provided with G...IRJET Journal
This document discusses the planning, design, and analysis of a G+3 hospital building provided with a grid slab. It begins by introducing grid slabs and their applications in large column-free spaces like auditoriums and showrooms. It then outlines the methodology used which includes modeling the structure in ETABS software, analyzing it to determine bending moments and shear forces, and designing all structural elements according to Indian codes. Key steps of the slab and grid beam design are shown as examples. In summary, this document presents the process of designing a 4-story hospital building with a grid slab structural system using ETABS software and verifying designs against code requirements.
STUDY OF HARPS PERIPHERAL AND PERIMETRAL BRACINGS PATTERN SHAPE IN PRE ENGINE...IRJET Journal
This document discusses the study of different bracing patterns used in pre-engineering buildings. It analyzes the harp, perimetral, and peripheral bracing patterns through 3D modeling and structural analysis software. The harp pattern directly controls column displacement through tensile beams. The perimetral pattern connects panels to control deflections and forces. The peripheral pattern minimizes deflections at eave ends. Analysis of the models found that the perimetral pattern most effectively controls lateral and longitudinal loads and is the most economical in terms of steel consumption.
Seismic Behaviour of Reinforced Concrete Flat Plate SystemsIRJET Journal
This document summarizes a study on the seismic behavior of reinforced concrete flat plate systems compared to traditional slab structures. A six-story building located in seismic zone II is modeled in ETABS software using both flat slab and conventional slab structures. Linear static and response spectrum analyses are performed to analyze storey displacements, shears, and overturning moments under earthquake loading based on Indian standards. The results are compared to determine how each structure type performs seismically, with findings showing the flat slab structure performs better in earthquakes than the traditional slab.
IRJET- Cost Comparison of different Grid Patterns of Floor Slab of Same SpanIRJET Journal
The document compares the cost of two grid patterns (two-way and diagonal) for floor slabs of the same 12x12m span. It describes the methodology used, which includes modeling the grids in STAAD Pro software, analyzing and designing them according to IS 456-2000 code, estimating construction quantities and costs. Analysis results show the diagonal grid has higher stiffness with deflections of 2.4mm compared to 0.735mm for the two-way grid. The document estimates concrete and reinforcement quantities required for each grid and concludes the diagonal grid is more economical with a lower structural cost per square foot.
The document summarizes the planning, analysis, and design of a multispecialty hospital building. It includes the objectives to prepare architectural drawings, analyze the G+2 building using STAAD Pro, and design the building according to IS 456:2000 using the working stress method. It describes analyzing the building's ability to resist lateral loads. Maximum bending moments in beams and columns will depend on their relative rigidity. Structural elements like slabs, beams, columns, footings, and staircases will be designed according to code specifications using the working stress method.
Design of prestressed Concrete flat slabs.pdf
The South African Institution of Civil Engineering
Postnet- Suite 81
Private bag X65
Halfway House 1685
South Africa
This Report is intended to serve as a manual of good practice for the design of prestressed concrete flat slabs..
In addition to the recommended procedures, other methods are described for the sake of completeness and to compare
different methods of design.
The Report was produced by a sub-committee of the Joint Structural Division of the South African Institution of Civil
Engineers, and the Institution of Structural Engineers.
PRESTRESSED CONCRETE FLAT SLABS
1.0 Introduction
In 1989 the Structural Division of the South African Institution of Civil Engineers created a sub-committee to examine
the design of prestressed concrete flat slabs. It was found that a certain amount of poor design was prevalent, and the
committee decided to produce a booklet of recommendations for good practice.
The matter was considered especially important because the South African Loading Code was changed with effect from
1990, and the required factor on D.L. is now 1.2, whereas it was previously 1.4. This has the effect of reducing
reinforcement areas, and cracking and deflection require more attention. To make allowance for this, SABS 0100 was
revised, and among other changes, the allowable concrete shear stress was reduced by 10 percent, to lessen the probability
of brittle shear failures.
1.1 Flat Slabs
Flat slabs were originally invented in the USA at the beginning of this century, and there were a number of patented
systems.
The early reinforced concrete flat slabs all had drops, and columns with capitals, and were considered to be the structure
of choice for warehouse construction and heavy loads. Because of the columns capitals and drops, shear was not really a
problem.
Design was based on tests on stresses in reinforcement at working loads, and the early codes required a total moment in
a span of WL2/11.
It was realized that statically a total moment of about WL2/8 was required for equilibrium, (If the column diameter is D,
the statically required moment is (very closely) W(L-2D/3)2/8 where L-2D/3 is the effective span. The difference between
WL2/11 and WL2/8 was attributed to a mystical '2 way action'. In fact it was due partly to tensile stresses in the concrete
and partly to arching effects reducing the measured stress in the reinforcement.
The philosophy, and the empirical coefficients, persisted until the 1950's when the allowable stresses in reinforcement
were increased, limit state design was introduced, and the statically required moment of WL2/8 was introduced into the
codes. This was because it was felt that it was not safe to rely on arching or tensile strength of the concrete. In addition
to the changed moment coefficients, the frame method of analysis was required in certain cases.
1.2 Flat Plates
Flat plates were subsequently developed, with no drops and no column capitals/
The document discusses guidelines for detailing reinforcement in concrete structures. It begins by defining detailing as the preparation of working drawings showing the size and location of reinforcement. Good detailing ensures reinforcement and concrete interact efficiently. The document then discusses sources of tension in concrete structures from various loading conditions like bending, shear, and connections. It provides equations from AS3600-2009 for calculating minimum development lengths for reinforcing bars to develop their yield strength based on bar size, concrete strength, and transverse reinforcement. It also discusses lap splice requirements. In summary, the document provides best practice guidelines for detailing reinforcement to efficiently resist loads and control cracking in concrete structures.
Structural Analysis and Design of Different types of Castellated BeamIRJET Journal
This document discusses the structural analysis and design of different types of castellated beams. It begins with an abstract that outlines the advantages of castellated beams in increasing strength and economy. It then discusses the use of castellated beams in various structures and the fabrication process. The document outlines the design process for castellated beams, which involves selecting cutting angles, computing loads and moments, checking shear capacity, and ensuring stress and deflection limits are not exceeded. It concludes that castellated beams allow for increased structural depth without weight increase, improving strength to weight ratios and reducing costs.
IRJET- Study & Improvement of Design and Construction Methodology of Precast ...IRJET Journal
The document studies the design and construction methodology of precast concrete segmental box culverts. It analyzes 6 alternative design modules for single and double box cells using different end conditions. Finite element analysis is conducted to determine the optimal section dimensions that result in minimum bending moments, shear forces, and principal stresses. Transportation cost is found to be lowest for a double box cell design with hinge joints at the top and bottom.
The document describes the design of a stepped footing to support a column with an unfactored load of 800 kN. A square footing with dimensions of 2.1m x 2.1m is designed with two 300mm steps. Reinforcement of #12 bars at 150mm c/c is provided. Checks are performed for bending moment, one-way shear, two-way shear, and development length which all meet code requirements. Therefore, the stepped footing design is adequate to support the given column load.
NONLINEAR FINITE ELEMENT ANALYSIS FOR REINFORCED CONCRETE SLABS UNDER PUNCHIN...IAEME Publication
This paper presents an implementation of a three-dimensional nonlinear finite element model for evaluating the behavior of reinforced concrete slabs under centric load. The concrete was idealized by using eight-nodded solid elements. While flexural reinforcement and the shear were modeled as line elements, a perfected bond between solid elements and line elements was assumed. The nonlinear behavior of concrete in compression is simulated by an elasto-plastic work-hardening model, and in tension a suitable post-cracking model based on tension stiffening and shear retention models are employed. The steel was simulated using an elastic-full plastic model. The validity of the theoretical formulations and the program used was verified through comparison with available experimental data, and the agreement has proven to be good. A parametric study has been also carried out to investigate the influence of the slab thickness on column-slab connection response
IRJET- Seismic Response of Flat Slab Buildings with Shear WallIRJET Journal
This document presents a study on the seismic response of flat slab buildings with shear walls. Response spectrum analysis and pushover analysis were conducted on flat slab building models and regular framed building models using ETABS software. The results show that flat slab buildings have higher displacement and lower base shear capacity compared to regular framed buildings. However, the addition of shear walls improves the seismic performance of flat slab buildings. Specifically, a flat slab building with a shear wall at its core location performed best with the lowest displacement, while exterior and interior shear wall locations had progressively higher displacement. Both linear and nonlinear analysis confirmed that shear walls increase the strength and seismic resistance of flat slab structures.
- The document describes the design and detailing of flat slabs, which are concrete slabs supported directly by columns without beams.
- Key aspects covered include dimensional considerations, analysis methods, design for bending moments including division of panels and limiting negative moments, shear design and punching shear, deflection and crack control, and design procedures.
- An example problem is provided to illustrate the full design process for an internal panel with drops adjacent to edge panels.
Large Span Lattice Frame Industrial Roof StructureIOSR Journals
This document presents the design of a large span lattice frame roof structure for an industrial building in India. It analyzes different configurations and member sizes for roof spans ranging from 30 to 60 meters under various load combinations, including dead load, live load, and wind load. Tables of results show bending moments and shear forces in the roof members for different roof slopes and column heights under a unit loading of 10 kN. The 60 meter span design case study is for a coal storage shed with a sloped lattice frame roof supported by columns. STAAD analysis software was used to optimize the structural system and select the most economical design.
Large Span Lattice Frame Industrial Roof StructureIOSR Journals
This document summarizes the design of a large span lattice frame roof structure for an industrial building in India. Key points include:
- The structure is a 60m span by 100m length roof for a coal storage shed.
- Various structural systems were analyzed using STAAD software to determine the most economical design.
- Load combinations considered dead load, live load, and wind loads according to Indian standards.
- Preliminary member sizing was conducted using a unit loading method, with the governing load combination being 10kN total at nodes from dead and live loads.
- Results of the analysis showed minimum moments and shears occurred for a roof slope between 7-9 degrees and a
This document presents the design of a large span lattice frame roof structure for an industrial building in India. It analyzes different configurations and member sizes for roof spans ranging from 30 to 60 meters under various load combinations, including dead load, live load, and wind load. Tables of results show bending moments and shear forces in the roof members for different roof slopes and column heights under a unit loading of 10 kN. The 60 meter span design with a slope of 8 degrees and column height of 5 meters is found to have the lowest bending moments and shear forces, making it the most economical solution.
A column is a vertical structural member subjected to compression and bending forces. Short columns fail through crushing or splitting, while slender columns fail through buckling. The document provides examples of calculating required reinforcement area and diameter for a short reinforced concrete column. It also provides examples of calculating the critical buckling load of a rod and determining a suitable universal column section for a given load based on its effective length and slenderness ratio.
This document summarizes a research paper that examines pricing strategy in a two-stage supply chain consisting of a supplier and retailer. The supplier offers a credit period to the retailer, who then offers credit to customers. A mathematical model is formulated to maximize total profit for the integrated supply chain system. The model considers three cases based on the relative lengths of the credit periods offered at each stage. Equations are developed to represent the profit functions for the supplier, retailer and overall system in each case. The goal is to determine the optimal selling price that maximizes total integrated profit.
The document discusses melanoma skin cancer detection using a computer-aided diagnosis system based on dermoscopic images. It begins with an introduction to skin cancer and melanoma. It then reviews existing literature on automated melanoma detection systems that use techniques like image preprocessing, segmentation, feature extraction and classification. Features extracted in other studies include asymmetry, border irregularity, color, diameter and texture-based features. The proposed system collects dermoscopic images and performs preprocessing, segmentation, extracts 9 features based on the ABCD rule, and classifies images using a neural network classifier to detect melanoma. It aims to develop an automated diagnosis system to eliminate invasive biopsy procedures.
This document summarizes various techniques for image segmentation that have been studied and proposed in previous research. It discusses edge-based, threshold-based, region-based, clustering-based, and other common segmentation methods. It also reviews applications of segmentation in medical imaging, plant disease detection, and other fields. While no single technique can segment all images perfectly, hybrid and adaptive methods combining multiple approaches may provide better results. Overall, image segmentation remains an important but challenging task in digital image processing and computer vision.
This document presents a test for detecting a single upper outlier in a sample from a Johnson SB distribution when the parameters of the distribution are unknown. The test statistic proposed is based on maximum likelihood estimates of the four parameters (location, scale, and two shape) of the Johnson SB distribution. Critical values of the test statistic are obtained through simulation for different sample sizes. The performance of the test is investigated through simulation, showing it performs well at detecting outliers when the contaminant observation represents a large shift from the original distribution parameters. An example application to census data is also provided.
This document summarizes a research paper that proposes a portable device called the "Disha Device" to improve women's safety. The device has features like live location tracking, audio/video recording, automatic messaging to emergency contacts, a buzzer, flashlight, and pepper spray. It is designed using an Arduino microcontroller connected to GPS and GSM modules. When the button is pressed, it sends an alert message with the woman's location, sets off an alarm, activates the flashlight and pepper spray for self-defense. The goal is to provide women a compact, one-click safety system to help them escape dangerous situations or call for help with just a single press of a button.
- The document describes a study that constructed physical fitness norms for female students attending social welfare schools in Andhra Pradesh, India.
- Researchers tested 339 students in classes 6-10 on speed, strength, agility and flexibility tests. Tests included 50m run, bend and reach, medicine ball throw, broad jump, shuttle run, and vertical jump.
- The results showed that 9th class students had the best average time for the 50m run. 10th class students had the highest flexibility on average. Strength and performance generally improved with increased class level.
This document summarizes research on downdraft gasification of biomass. It discusses how downdraft gasifiers effectively convert solid biomass into a combustible producer gas. The gasification process involves pyrolysis and reactions between hot char and gases that produce CO, H2, and CH4. Downdraft gasifiers are well-suited for biomass gasification due to their simple design and ability to manage the gasification process with low tar production. The document also reviews previous studies on gasifier configuration upgrades and their impact on performance, and the principles of downdraft gasifier operation.
This document summarizes the design and manufacturing of a twin spindle drilling attachment. Key points:
- The attachment allows a drilling machine to simultaneously drill two holes in a single setting, improving productivity over a single spindle setup.
- It uses a sun and planet gear arrangement to transmit power from the main spindle to two drilling spindles.
- Components like gears, shafts, and housing were designed using Creo software and manufactured. Drill chucks, bearings, and bits were purchased.
- The attachment was assembled and installed on a vertical drilling machine. It is aimed at improving productivity in mass production applications by combining two drilling operations into one setup.
The document presents a comparative study of different gantry girder profiles for various crane capacities and gantry spans. Bending moments, shear forces, and section properties are calculated and tabulated for 'I'-section with top and bottom plates, symmetrical plate girder, 'I'-section with 'C'-section top flange, plate girder with rolled 'C'-section top flange, and unsymmetrical plate girder sections. Graphs of steel weight required per meter length are presented. The 'I'-section with 'C'-section top flange profile is found to be optimized for biaxial bending but rolled sections may not be available for all spans.
This document summarizes research on analyzing the first ply failure of laminated composite skew plates under concentrated load using finite element analysis. It first describes how a finite element model was developed using shell elements to analyze skew plates of varying skew angles, laminations, and boundary conditions. Three failure criteria (maximum stress, maximum strain, Tsai-Wu) were used to evaluate first ply failure loads. The minimum load from the criteria was taken as the governing failure load. The research aims to determine the effects of various parameters on first ply failure loads and validate the numerical approach through benchmark problems.
This document summarizes a study that investigated the larvicidal effects of Aegle marmelos (bael tree) leaf extracts on Aedes aegypti mosquitoes. Specifically, it assessed the efficacy of methanol extracts from A. marmelos leaves in killing A. aegypti larvae (at the third instar stage) and altering their midgut proteins. The study found that the leaf extract achieved 50% larval mortality (LC50) at a concentration of 49 ppm. Proteomic analysis of larval midguts revealed changes in protein expression levels after exposure to the extract, suggesting its bioactive compounds can disrupt the midgut. The aim is to identify specific inhibitor proteins in the midg
This document presents a system for classifying electrocardiogram (ECG) signals using a convolutional neural network (CNN). The system first preprocesses raw ECG data by removing noise and segmenting the signals. It then uses a CNN to extract features directly from the ECG data and classify arrhythmias without requiring complex feature engineering. The CNN architecture contains 11 convolutional layers and is optimized using techniques like batch normalization and dropout. The system was tested on ECG datasets and achieved classification accuracy of over 93%, demonstrating its effectiveness at automated ECG classification.
This document presents a new algorithm for extracting and summarizing news from online newspapers. The algorithm first extracts news related to the topic using keyword matching. It then distinguishes different types of news about the same topic. A term frequency-based summarization method is used to generate summaries. Sentences are scored based on term frequency and the highest scoring sentences are selected for the summary. The algorithm was evaluated on news datasets from various newspapers and showed good performance in intrinsic evaluation metrics like precision, recall and F-score. Thus, the proposed method can effectively extract and summarize online news for a given keyword or topic.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
The CBC machine is a common diagnostic tool used by doctors to measure a patient's red blood cell count, white blood cell count and platelet count. The machine uses a small sample of the patient's blood, which is then placed into special tubes and analyzed. The results of the analysis are then displayed on a screen for the doctor to review. The CBC machine is an important tool for diagnosing various conditions, such as anemia, infection and leukemia. It can also help to monitor a patient's response to treatment.
LLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by Anant
77201946
1. International Journal of Research in Advent Technology, Vol.7, No.7, July 2019
E-ISSN: 2321-9637
Available online at www.ijrat.org
29
doi: 10.32622/ijrat.77201946
Abstract— Flat Slabs are highly adaptable elements
widely used in construction, providing minimum depth, fast
construction. In flat slabs, the beams used in conventional
slabs are no more and the slab is made to rest directly over the
columns. A drop panel or a column head is provided in case
of higher loads to reduce the load intensity. Flat slabs are
particularly suitable for areas where, for acoustic or fire
reasons, tops of partitions need to be sealed to the slab soffit.
This study concerns mainly the comparison of conventional
and flat slab with and without slab drops by comparing the
quantity of steel and bending moment in slabs of various
spans 20 x 20m, 40 x 40m, 60 x 60m. Each slab is sub divided
into different panels of sizes 5x5m, 10x10m, 15x15m.
Index Terms— Flat slab, Interior Panel, Exterior Panel,
Column strip, Middle strip, Slab drop.
I. INTRODUCTION
Flat slabs construction system is the one in which
the beams used in the conventional construction methods are
eliminated. The slab rests directly on the column and the slab
load is transferred directly to the columns and then to the
foundation. The thickness of the slab near the support with
the column is increased in order to support heavy loads and
these are called slab drops and generally supplied with
enlarged heads called column heads or capitals. Absence of
beam gives a plain ceiling, thus giving better architectural
appearance than in usual cases where beams are used.
Flat slab construction can significantly decrease floor to
floor height, particularly in the lack of a false ceiling, since
flat slab construction acts as a limiting factor in the
positioning of horizontal services and partitions [1]. This can
prove gainful in case of lower building height, decreased
cladding expense and pre-fabricated services.
In case the client plans changes in the interior and wants to
use the accommodation to suit the need, flat slab construction
is the perfect choice as it offers that flexibility to the
owner.[6]
Types of Flat slabs:
• Typical Flat Slab
• Slab without drop and column with column head
Manuscript revised July 19, 2019 and published on August 20, 2019
B. P. R.V. S. Priyatham, Department of Civil Engineering, GMR Institute of
Technology, Rajam.
Er. D. V. S. K. Chaitanya, Department of Civil Engineering, ANU College
of Engineering and Technology, Guntur.
• Slab with drop and column without column head
• Slab with drop and column with column head
Components of a Flat Slab
Slab Drop
Column Head
Middle Strip
Column Strip
Fig.1 .Typical Components of a Flat Slab
Drop: The drops are nothing but the enlarged part below the
slab at the intersection of column and slab. The main aim is to
resist the punching shear which is predominant at the contact
of slab and column Support. One of the most important
criteria to be followed without fail is that the drop dimension
should not be less than one -third of panel length in that
direction.[2]
Column Head: Column Head is the bulged area over the
column constructed to resist the slab load coming on to it.
The column head is usually provided under the slab drop if
necessary or as per the design requirement. Some amount of
negative moment at the support is transferred from the slab to
the column. The area at the support must be increased in
order to resist this negative moment.
S.S.Patil, Rupali Sigi [7] said that in every code book it
suggests any of the two methods as Direct Design Method
and Equivalent Frame Method for gravity load analysis of flat
slab. Design of Flat slab by Direct Design Method has some
restrictions that (a) It should have minimum three spans in
each directions. (b) It should not have staggered column
orientation. Hence Equivalent Frame Method is adopted.
Comparative Study on Analysis and Design of
Flat Slabs with Conventional Slabs
B. P. R. V. S. Priyatham, Er. D. V. S. K. Chaitanya
2. International Journal of Research in Advent Technology, Vol.7, No.7, July 2019
E-ISSN: 2321-9637
Available online at www.ijrat.org
30
doi: 10.32622/ijrat.77201946
II. DESIGN METHODS AND METHODOLOGY
The design of flat slab consists of two approximate methods
namely Direct Design Method and Equivalent Frame
Method.
Step1: Finding the depth of slab.
Step2: Finding the depth of slab drop.
Step3: Finding the diameter of the column head.
Step4: Finding the width of middle strip and
column Strip.
Step5: Consideration of the loads as per
requirements.
(In the case of exterior panel calculation of the
stiffness factor is compulsory)
Step6: Calculation of the Factored Bending
Moment.
Step7: Calculation of negative and positive bending
moments of column strip and middle strip.
Step 8: calculation of shear stresses and check for
the permissible shear.
Step 9: calculation of reinforcements of all the
column and middle strips.
Step 10: check for the deflection.
III. DESIGN CALCULATIONS
In the present study we are comparing bending moments
and area of steel for conventional slab, flat slab with drop and
flat slab without drop having slab sizes of 20m*20m,
40*40m, 60m*60m each slab is further divided into panels of
sizes 5m*5m, 10m*10m, 15m*15m with exterior and interior
panels.
The following are the considerations made in this design.
Dead load = 25kN/m3
Live load = 4.5kN/m2
Floor finish = 1.5kN/m2
Column dia in case of flat slab with drop = 400mm
Column size in case of flat slab without drop =
300mm*450mm
Diameter of primary reinforcing bar = 16mm, 10mm
Diameter of secondary reinforcing bar = 8mm
CASE I: DESIGN OF FLAT SLAB WITHOUT SLAB
DROP OF SIZE 20 x 20m
Design of Interior Panel 5 x 5m
Column size = 300*400mm
Live Load = 4.5kN/m2
Floor Finish = 1.5kN/m2
Height of column is 4m above & below the slab. M20 & Fe415
Depth of slab
L/d = 32 (Clause 31.2)
5000/32 = d
d = 156.25mm ~ 160
Provide Overall depth, D = 185mm
Fig.2 .Plan of Flat Slab without Slab Drop (20 x 20m)
Load Calculations
Self-weight of slab = 0.185*25 = 4.625kN/m2
Floor Finish = 1.5kN/m2
Live Load = 4.5kN/m2
Total Factored Load = 15.93kN/m2
Dead Load = 4.625 + 1.5 = 6.125kN/m2
Live Load = 4.5kN/m2
Along Longer direction
For Slab
KS = 4EI/l = 2.11*106
E
For Column
KC= 4EI/l = 1.6*106
E
αc= 𝝨KC/𝝨KS = 0.758
Along Shorter direction
For Slab
KS = 4EI/l = 2.11*106
E
For Column
KC = 4EI/l = 0.9*106
αc = 𝝨KC/𝝨KS = 0.426
Check for correction due to pattern loading
(IS 456-2000, Clause 31.4.6) [5]
Ratio = Live Load/ Dead Load = 4.5/6.125 = 0.734 > 0.5
Check for pattern loading is required
Check along longer direction
l2/l1 = 5000/5000 = 1.0
Live Load / Dead Load = 0.734
wl /wd = 0.5; αcmin = 0
wl /wd = 1.0; αcmin= 0.7
αCalculated > αcmin (0.9 > 0.7)
No correction is required.
Check for pattern loading is same along shorter span also
Total design moment
Along Longer direction
Mu = Wln/8
W = wl2ln
ln = 5 - 0.2 - 0.2 = 4.6m
3. International Journal of Research in Advent Technology, Vol.7, No.7, July 2019
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doi: 10.32622/ijrat.77201946
Mu = 15.9375*5*4.62
/8
Mu = 210.77 kNm
Along Shorter direction
Mu = Wl2ln
2
/8 = 210.77 kNm
Column Strip and Middle Strip
Along Longer direction (page no:53, Clause 1.31.1.1)
2*0.25*5000 = 2500
2*0.25*5000 = 2500
Provide Smaller of two values.
Width of column strip = 2500mm
Width of middle Strip = 5000-1250-1250 = 2500mm
Along Shorter direction
Width of Column strip = 2500mm
Middle Strip = 2500mm
Reinforcement in both directions
Column Strip
Mu (-ve) = 0.65*0.75*210.77 = 102.75kNm
Ast (-ve) = 1983.6mm2
Mu (+ve) = 0.5*0.6*210.77 = 44.26kNm
Ast (+ve) = 799.7mm2
Middle Strip
Mu (-ve) = (0.65*210.77) – 102.75 = 34.25kNm
Ast (-ve) = 612.6mm2
Mu (+ve) = (0.35*210.77) – 102.75 = 28.81kNm
Ast (+ve) = 512.9mm2
Check for two-way shear
d/2 = 160/2 = 80mm
Vu = 394.332kN
bu = 2(560+460) = 2040mm
Tv = Vu/bu*d = 1.208N/mm2
IS 456:2000 (Clause 31.6.3.1)
Tc
'
= KsTc, Ks= 0.5+300/400 = 1.25>1.0
Tc = 0.25√ =1.11
Tc
'
= 1.11N/mm2
, Tv > Tc
'
Hence Shear Reinforcement is Required.
Design of shear Reinforcement
Consider 8ϕ Stirrups, 8 legged Fe415
Sv = 0.87*415*Asv*d/Vus
Asv =402m2
Vus = Vu - 0.5TcbodKs = 213.830*103
N
Sv = 108.93 ≈ 110mm
Table I BENDING MOMENT AND AREA OF STEEL FOR INTERIOR
PANEL WITHOUT DROP
Panel
Sizes
(m)
Column Strip Middle Strip
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
5*5
102.75(-ve) 1983.6 34.25(-ve) 612.65
44.26(+ve) 799.2 28.81(+ve) 512.98
10*10
1242.15(-ve) 12927.8 414.18(-ve) 3771.07
535.48(+ve) 4953.23 356.6(+ve) 3319.53
15*15
5406.85(-ve) 42521.87 1802.28(-ve) 11389.79
2329.10(+ve) 15068.89 1489.74(+ve) 9291.62
Design of Exterior Panel 5 x 5m
In the design of exterior panel preliminary data is same as of
interior panel design and so the total design moments along
the longer and shorter directions are considered from that and
the moment distribution should be done. Also the width of
column and middle strips is also same.
Total design moment Mu = 210.77kNm
Moment Distribution
Interior negative design moment = 0.75 - =
0.702
Positive design moment = 0.63 - = 0.497
Exterior negative design moment = = 0.31
Based on the moment distribution the area of steel can be
calculated in both the directions and the check for two way
shear is same as for interior panel.
Reinforcement in both directions
Column Strip
Mu (-ve) = 0.31*210.77 = 65.33kNm
Ast (-ve) = 1207mm2
Mu (+ve) = 0.6*0.497*210.77 = 62.85kNm
Ast (+ve) = 1158.08mm2
Middle Strip
Mu (+ve) = (0.497*210.77) – 61.37 = 41.92kNm
Ast (+ve) = 755.6mm2
TABLE II BENDING MOMENT AND AREA OF STEEL FOR
EXTERIOR PANEL WITHOUT DROP
Panel
Sizes
(m)
Column Strip Middle Strip
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
5*5
65.33(-ve) 1207 - -
62.85(+ve) 1158.08 41.92(+ve) 755.6
10*10
163.12(-ve) 1446.6 - -
884.8(+ve) 8583.4 618.7(+ve) 5792.93
15*15
262.85(-ve) 1564.18 - -
3501.3(+ve) 24047.02 2859.41(+ve) 18917.2
CASE II: DESIGN OF FLAT SLAB WITH SLAB DROP
OF SIZE 20 x 20m
Design of Interior Panel 5 x 5m
Materials: M20 Grade and Fe415
Design of Interior panel dimension 5m*5m
(l/d) = 32
Two-way Continuous Slab as per IS 456: 2000
Thickness of slab at mid span (5000/32) = 156.25 ≈ 160mm
Adopt Effective Depth, d = 160mm
Overall Depth, D = 185mm
4. International Journal of Research in Advent Technology, Vol.7, No.7, July 2019
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doi: 10.32622/ijrat.77201946
Fig.3 .Plan of Flat Slab with Slab Drop (20 x 20m)
Fig.4 .Isometric View of Flat Slab with Slab Drop (20 x 20m)
According to Code ACI 318 the projection below slab drop
should not be less than 1/4(Slab Thickness) and also should
be less than or not equal to 100mm.
Hence thickness of slabs at drops (185+100) = 285mm
Column Head Diameter not greater than 0.25L = 0.25*5000
= 1250mm
Length of Drop should not less than (L/3)
= 5000/3 = 1666.6mm
Adopt Drop Width = 2500mm
Column Strip = Drop width = 2500mm
Width of middle Strip = 2500mm
Loading Specifications
Live Load of slab = 4.5kN/m2
Dead Load of slab = 5.5625kN/m2
Floor Finishers = 1.5kN/m2
Total Service Load = 11.5625kN/m2
Factored Load = 17.34kN/m2
Factored Bending Moment
As per the IS 456-2000 Clause 31.4.2.2 the total moment is
calculated as follows
Mo = Wln/8
Ln = 5 - 1.25 = 3.75m
L1 = L2 = 5m
W = wuL2ln = 325.125kN
Mo = 152.40kNm
Reinforcement
Column Strip
Mu (-ve) =49% Mo = 0.49*152.40 = 74.67kNm
Mu = 0.89*415*Ast*d*(1-Astfy/b*d*fck)
74.67*106
= 0.89*415*Ast*260*(1-415Ast/2.5*103
*260*20)
Ast (-ve) = 817.15mm2
Mu (+ve) = 21% Mo = 0.21*152.40 = 32kNm
Ast (+ve) = 344.89mm2
Middle Strip
Mu (-ve) = 15% Mo = 0.15*152.40 = 22.86kNm
Ast (-ve) = 406mm2
Mu (+ve) = 15% Mo = 0.15*152.40 = 22.86kNm
Ast (+ve) = 406mm2
Check For thickness of slab
For balanced section Mu = 0.138fckbd2
Thickness of slab near drops (Column strip)
d = √ = 104.02mm
Thickness of slab in middle strips
d = √ = 52.54mm
Overall depth near drops = 285mm
Effective depth near drop = 250mm
Overall depth (Middle Strip’s) = 185mm
Effective depth (Middle Strip) = 160mm
Check for Shear Stress
Shear Stress is checked near the column head at section (D +
d) near column head.
W1 = 𝝥/4(D+ d) 2
Wu = 30.626kN
Shear Force = (total load) – (Load on circular Area)
= (17.34*5*5) - 30.62 = 402.88kN
Shear force per meter of perimeter = [
] = 85.537kN
Shear Stress = 85.537*103
/ (1000*250) = 0.34N/mm2
As per IS 456:2000 Clause 31.6.3.1
Permissible shear stress = KsTc
Ks = (0.5+ 𝜷c), 𝜷c = L/L2 = 1
Ks = (0.5+1) = 1.5 But should not be greater than 1.0
Tc = 0.25√ = 0.25√ = 1.118N/mm2
KsTc = 1.118N/mm2
= 0.342<1.118N/mm2
Check for Deflection Control
According to the IS 456:2000, Clause 23.2.1
Pt = 100Ast/bd
= (100*406/1000*160) = 0.254
Figure:4 of IS 456:2000 modification factor for tension
reinforcement
Kt = 1.8
(L/d)max = (1.8*32) = 57.6//1.1*32 = 35.2
5. International Journal of Research in Advent Technology, Vol.7, No.7, July 2019
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doi: 10.32622/ijrat.77201946
(L/d)provided = 5000/160 = 31.25
31.25<57.6
The designed Slab satisfies deflection limit.
Table III BENDING MOMENT AND AREA OF STEEL FOR INTERIOR
PANEL WITH SLAB DROP
Panel
Sizes
(m)
Column Strip Middle Strip
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
5*5
74.67(-ve) 817.15 22.86(-ve) 406
32(+ve) 344.89 22.86(+ve) 406
10*10
826.87(-ve) 5786.4 253.12(-ve) 2258.09
354.37(+ve) 2394.76 253.12(+ve) 2258.09
15*15
5703.49(-ve) 33020 1745.96(-ve) 8869.95
2444.35(+ve) 12661.14 1745.96(+ve) 8869.95
Design of Exterior Panel 5 x 5m
Loading class = 4.5kN/m2
, M20, Fe415
Height of Story = 3m
Thickness of slab in column strip = 285m
Thickness of slab in middle strip = 185mm
Dimensions of Flat slab
Width of middle strip = Width of column =
Drop width = 2.5m
Stiffness Computation
Kc = 4Eclc/l = 1.67*106
Ec
Assuming columns both at top and bottom
Kc = 2(1.67*106
)Ec
Stiffness of slab
Ks = 4*5000*3003
/12*5000 = 21.33*106
Ec
𝝰c = 𝝨Kc/𝝨Ks = 0.156
𝝰c(min) = 0.7 for (L2/L1) = 1.0
(1+1/𝝰c) = 7.41
Ln = 5 - 1.25 = 3.75m
Bending Moment
Total Load = W = wul2Ln = 325.125kN
Bending Moment Mo = (325.125*3.75)/8 = 152.40kNm
Interior Negative design moment
( )Mo = 112.24kNm
Positive design moment
( )Mo = 78.45kNm
Exterior Negative design moment
( )Mo = 13.36kNm
Interior Negative design moment
Column strip = 0.75*112.24 = 84.18kNm
Middle strip = 0.25*112.24 = 28.06kNm
Exterior Negative design moment
Column strip = 13.36kNm
Middle Strip = 0
Positive moment in column strip
0.60*84.18 = 50.508kNm
Positive moment in Middle strip
0.40*84.18= 33.672kNm
Thickness of Slab near Drops
d= √ = 110.45mm
Thickness of Slab in middle Strip
d = √ = 69.85mm
Reinforcement
Column Strip Interior Negative Bending moment
= 0.87fyAstd( )
84.18*106
= 0.87*415*Ast*260*( )
Ast = 924.47mm2
Ast for positive Bending Moment
50.508*106
= 0.87*415*Ast*160*( )
Ast = 918.52mm2
Middle Strip
33.672*106
= 0.87*415*Ast*160*( )
Ast = 601.97mm2
Column Strip
13.36*106
= 0.87*415*Ast*260*( )
Ast = 143.04mm2
TABLE IV BENDING MOMENT AND AREA OF STEEL FOR
EXTERIOR PANEL WITH SLAB DROP
Panel
Sizes
(m)
Column Strip Middle Strip
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
Bending
Moment
(kNm)
Area of
Steel
(mm2
)
5*5
84.18(-ve) 924.47 - -
50.5(+ve) 918.52 33.67(+ve) 601.97
10*10
932.13(-ve) 6577 - -
559.28(+ve) 5192 372.85(+ve) 3376.65
15*15
6429.5(-ve) 6577 - -
3857.7(+ve) 5192 2571.82(+ve) 3376.65
CASE III: DESIGN OF CONVENTIONAL TWO WAY
SLAB OF SIZE 20 x 20m
Materials: Adopt M20&Fe415.
Lx = 5m
Ly = 5m (Ly/Lx=1)
Fck = 20N/mm2
Fy = 415N/mm2
Depth of slab
As the span more than 3.5m adopt a span/depth ratio of 25
Depth = Span/25 = 5000/25 = 200mm
Adopt effective depth, d = 175mm
Effective Span
Effective span = Clear span + Effective depth = 4.87m
Loads
Self-weight of slab = (0.2*2.5) = 5kN/m2
Live load on slab = 4kN/m2
Floor finish = 1.5kN/m2
6. International Journal of Research in Advent Technology, Vol.7, No.7, July 2019
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doi: 10.32622/ijrat.77201946
Total working load = 10.5kN/m2
Design ultimate load = 15.75kN/m2
i) Interior Panel
Ultimate Design moments & Shear forces
For, (Ly/Lx=1) αx = 0.032, αy = 0.024
Mux = αxwuLx
2
= 11.95kNm
Muy = αywuLy
2
= 8.96kNm
Vux = 0.5wuLx = 32.60kNm
Area of reinforcement
Ast = 0.5fck/fy[ √ ]bd = 193.67mm2
Astmin = 0.0012*175*1000 = 210mm2
Ast< Astmin
Hence provide minimum reinforcement
Reinforcements Along Short span
Ast = 0.5fck/fy[ √ ]bd = 145mm2
Ast min = 210mm2
Hence provide minimum reinforcement
ii) Two Adjacent Edges Discontinuous
Ultimate Design moments & Shear forces
As per the codebook the ratio (Ly/Lx=1)
Mux (-ve) = (αxwuLx
2
) = 0.047*15.75*4.872
= 17.55kNm
Mux(+ve) = (αxwuLy
2
) = 0.035*15.75*4.872
= 13.07kNm
Muy(-ve) = (αxwuLy
2
) = 0.042*15.75*4.872
= 15.668kNm
Muy(+ve) = (αxwuLy
2
) = 0.035*15.75*4.872
= 13.07kNm
Area of reinforcement
Ast(-ve)= 0.5fck/fy[ √ ]bd = 287.7mm2
Reinforcement along Short span
Ast(-ve) = 255.668mm2
Ast(+ve) = 212mm2
iii) One Edge Discontinuous
Ultimate Design moments & Shear forces
For, (Ly/Lx=1) αx = 0.047, αy = 0.035
Mux (-ve ) = αxwuLx
2
= 0.037*15.75*4.872
= 13.82kNm
Mux(+ve) = αxwuLy
2
= 0.028*15.75*4.872
= 13.07kNm
Muy(-ve) = αxwuLy
2
= 0.037*15.75*4.872
= 15.668kNm
Muy(+ve) = αxwuLy
2
= 0.028*15.75*4.872
=13.07kNm
Vux = 0.5wuLx = 0.5*15.75*4.87 = 38.35kNm
Area of reinforcement
Ast(-ve) = 0.5fck/fy[ √ ]bd = 224.8mm2
Ast(+ve) = 212mm2
Reinforcement Along Short span
Ast(-ve) = 224.8mm2
Ast(+ve) = 212mm2
Check for shear stresses
Tv = Vu/bd = 0.186N/mm2
Pt = 100Ast/bd = 0.135N/mm2
From IS 456 Table 19, Tc = 0.28N/mm2
Tv < Tc
Hence no shear reinforcement is required.
Check for deflection
As per IS 456:2000 the ratio of (L/d)basic = 20
Pt = 0.135
Kt = 1.8
(L/d)max = 20*1.8
(L/d)provided = 5000/170 = 28.5 < 36
Hence deflection control is satisfied
Check for cracking
Steel provided is more than the minimum % of reinforcement
Spacing of main steel < 3d = 3*175 = 525mm
Diameter of reinforcement < D/8 = 200/8 = 25mm
Hence cracks are within permissible limits.
Torsion reinforcement at corners
Area of reinforcement in each 4 layers = (0.25*210) =
157.5mm2
Distance over which torsion reinforcement is provided =
1/5(short span) = 1/5(50000) = 1000mm
Provide 6mm diameter at 1000mm centers for a length of
1000mm@all 4 layers in 4 corners.
Fig.5 .Variation of Interior Panel Bending Moments for different panel sizes
for flat slab without drop
Fig.6 .Variation of Exterior Panel Bending Moments for different panel sizes
for flat slab without drop
102.75 44.26 34.25 28.81
1242.15
535.48 414.18 356.6
5406.85
2329.1
1802.28
1489.74
0
1000
2000
3000
4000
5000
6000
CS(-Ve
BM)
CS(+Ve
BM)
MS(-Ve
BM)
MS(+Ve
BM)
BendingMoment(kNm)
5*5
10*10
15*15
65.33 62.85 0 41.92163.12
884.8
0
618.7
262.85
3501.3
0
2859.41
0
500
1000
1500
2000
2500
3000
3500
4000
CS (-Ve BM)CS (+Ve BM)MS (-Ve BM)MS (+Ve BM)
BendingMoment(kNm)
5*5
10*10
15*15
7. International Journal of Research in Advent Technology, Vol.7, No.7, July 2019
E-ISSN: 2321-9637
Available online at www.ijrat.org
35
doi: 10.32622/ijrat.77201946
Fig.7 .Variation of Interior Panel Bending Moments for different panel sizes
for flat slab with Slab Drop
Fig.8 .Variation of Exterior Panel Bending Moments for different panel sizes
for flat slab with Slab Drop
IV. CONCLUSION
1. It was observed that the value of the bending moment of
flat slab without drop increases when compared to flat
slab with drop of equal dimensions.
2. It was observed that the value of the bending moment of
flat slab is higher when compared to conventional slab of
equal dimensions.
3. When a flat Slab with drop is considered it was observed
that there is an increase in the percentage of bending
moment of 44.65, 54.42 for panel dimensions of 5*5m,
10*10m respectively when compared with flat slab
without drop and there is a decrease in the percentage of
bending moment of 3.90 for panel dimensions 15*15m.
4. When a flat Slab with drop is considered it was observed
that there is an increase in the percentage of bending
moment of 56.45, 67.06 for panel dimensions of 5*5m,
10*10m respectively when compared with flat slab
without drop and there is a decrease in the percentage of
bending moment of 4.70 for panel dimensions 15*15m.
5. When a flat Slab with drop is considered it was observed
that there is a decrease in the percentage of bending
moment of 18.97, 82.50, and 95.91 for panel dimensions
of 5*5m, 10*10m, and 15m*15m respectively.
REFERENCES
[1] Gaurav Ravindran Chavan, ―Analysis and Design of Flat Slab,‖
International Journal of Latest Trends in Engineering and Technology,
vol.7, Issue 1, 2016.
[2] Patil, K.S.,Gore, N.G.,Salunke, P.J., ―Optimum design of reinforced
concrete flat slab with Drop Panel‖, International Journal of Recent
Technology and Engineering, Vol. 2, September 2013.
[3] Bhavikatti S. S, Advance R.C.C. Design, New Age International (P)
Limited Publishers, New Delhi, India
[4] N. Krishna Raju, Advanced Reinforced Concrete Design, CBS
Publisher 2015.
[5] IS 456:2000, ―Indian Standard Code Of Practice For Plain and
Reinforced Concrete‖, Fourth Revision, Bureau of Indian Standards,
New Delhi, July, 2000.
[6] Mitan Kathrotiya, Kaushal Parikh, ―Study on Flat Slab and
Conventional Slab‖, International Journal of Scientific Research and
Development”, Vol. 5, Issue 1, 2017.
[7] S.S.Patil, Rupali Sigi, ―Analysis and Design of Flat Slabs Using
Various Codes”, Internatiomal Journal of Research in Engineering
and Technology‖, Vol.3, Issue 4, 2014.
AUTHORS PROFILE
B. P. R. V. S. Priyatham is an Assistant Professor at GMR
Institute of Technology, Rajam. He has graduated in
Masters of Engineering from Andhra University and his
research area is Coldformed Steel Structures.
Er D. V. S. K. Chaitanya is an Assistant Professor at ANU
College of Engineering and Technology, Acharya
Nagarjuna University, Guntur. He has graduated in Masters
of Engineering from Andhra University and is currently
pursuing his PhD in Civil Engineering. He is a member of
professional bodies like ICI and IIID.
74.67 32 22.86 22.86
826.87
354.37 253.12 253.12
5703.49
2444.35 1745.96 1745.96
0
1000
2000
3000
4000
5000
6000
CS (-Ve
BM)
CS (+Ve
BM)
MS (-Ve
BM)
MS (+Ve
BM)
BendingMoment(kNm)
5*5
10*10
15*15
84.18 50.5 0 33.67
932.13
559.28
0
372.85
6429.57
3857.74
0
2571.82
0
1000
2000
3000
4000
5000
6000
7000
CS (-Ve
BM)
CS (+Ve
BM)
MS (-Ve
BM)
MS (+Ve
BM)
BendingMoment(kNm)
5*5
10*10
15*15