A pile cap is a reinforced concrete structure that interconnects a group of piles and transfers loads from columns or walls to the piles. It is designed to distribute forces equally to the piles. Pile caps are designed using truss theory for closely spaced piles or beam theory for widely spaced piles. Key aspects of pile cap design include ensuring adequate size, depth, reinforcement, and structural strength to resist bending moments, shear forces, and punching shear from supported loads. Pile cap design involves checking capacities of individual piles and reinforcement requirements to achieve strength and serviceability limits stated in design codes.
This document describes the design of a pile cap by a group of civil engineering students. It defines a pile cap as a concrete mat that rests on piles driven into soft ground to provide a stable foundation. It then provides two examples of pile cap design, showing dimensions, load calculations, reinforcement requirements and construction details. The document concludes that a pile cap distributes a building's load to piles to form a stable foundation on unstable soil. It acknowledges the guidance of professors in completing this project.
Is code underremead pile Bearing capacityMake Mannan
This document provides information on an Indian Standard code of practice for the design and construction of under-reamed pile foundations. It begins with background information on under-reamed piles and how they provide substantial bearing and anchorage in various soil conditions. It then provides definitions of key terms related to pile foundations. The document outlines the necessary site investigation and soil property information required for the design and construction of under-reamed piles. It also includes sections on load testing, design considerations, construction methods, and other recommendations for under-reamed piles.
The document discusses reinforced concrete columns, including their functions, failure modes, classifications, and design considerations. Columns primarily resist axial compression but may also experience bending moments. They can fail due to compression, buckling, or a combination. Design depends on whether the column is short or slender, braced or unbraced. Reinforcement is designed based on the column's expected loads and dimensions using methods specified in design codes like BS 8110.
A raft foundation is a large concrete slab that interfaces columns with the base soil. It can support storage tanks, equipment, or tower structures. There are different types including flat plate, plate with thickened columns, and waffle slab. The structural design uses conventional rigid or flexible methods. It involves determining soil pressures, load eccentricities, moment and shear diagrams for strips, punching shear sections, steel reinforcement, and checking stresses. A beam-slab raft foundation design follows the same process as an inverted beam-slab roof.
A group of 16 square piles extends 12 m into stiff clay soil, underlain by rock at 24 m depth. Pile dimensions are 0.3 m x 0.3 m. Undrained shear strength of clay increases linearly from 50 kPa at surface to 150 kPa at rock. Factor of safety for group capacity is 2.5. Determine group capacity and individual pile capacity.
The group capacity is calculated to be 1600 kN. The individual pile capacity is determined to be 100 kN. The factor of safety of 2.5 is then applied to determine the safe load capacity.
This document provides information about the design of strap footings. It begins with an overview of strap footings, noting they are used to connect an eccentrically loaded column footing to an interior column. The strap transmits moment caused by eccentricity to the interior footing to generate uniform soil pressure beneath both footings.
It then outlines the basic considerations for strap footing design: 1) the strap must be rigid, 2) footings should have equal soil pressures to avoid differential settlement, and 3) the strap should be out of contact with soil to avoid soil reactions. Finally, it provides the step-by-step process for designing a strap footing, including proportioning footing dimensions, evaluating soil pressures, designing reinforcement,
This document provides an example of designing a rectangular reinforced concrete beam. It includes calculating the loads, bending moment, required tension reinforcement, checking shear capacity and deflection. For a simply supported beam with a uniformly distributed load, the document calculates the steel reinforcement area required using formulas and tables. It then checks that the beam satisfies requirements for shear capacity, minimum and maximum steel ratios, and deflection. The document also provides an example of designing a doubly reinforced beam.
Footings transfer structural loads from a building to the ground. This document discusses various types of footings and their design procedures. Spread footings are the most common type and are proportioned to have an area large enough that soil and building settlement will be minimized. The general design process involves checking that factored loads are less than the soil's allowable bearing capacity and footing thickness is sufficient to resist punching and beam shear. Reinforcement is calculated and placed to resist bending stresses. Combined and strap footings are also discussed along with their unique design considerations. Brick footings can be used for small residential loads.
This document describes the design of a pile cap by a group of civil engineering students. It defines a pile cap as a concrete mat that rests on piles driven into soft ground to provide a stable foundation. It then provides two examples of pile cap design, showing dimensions, load calculations, reinforcement requirements and construction details. The document concludes that a pile cap distributes a building's load to piles to form a stable foundation on unstable soil. It acknowledges the guidance of professors in completing this project.
Is code underremead pile Bearing capacityMake Mannan
This document provides information on an Indian Standard code of practice for the design and construction of under-reamed pile foundations. It begins with background information on under-reamed piles and how they provide substantial bearing and anchorage in various soil conditions. It then provides definitions of key terms related to pile foundations. The document outlines the necessary site investigation and soil property information required for the design and construction of under-reamed piles. It also includes sections on load testing, design considerations, construction methods, and other recommendations for under-reamed piles.
The document discusses reinforced concrete columns, including their functions, failure modes, classifications, and design considerations. Columns primarily resist axial compression but may also experience bending moments. They can fail due to compression, buckling, or a combination. Design depends on whether the column is short or slender, braced or unbraced. Reinforcement is designed based on the column's expected loads and dimensions using methods specified in design codes like BS 8110.
A raft foundation is a large concrete slab that interfaces columns with the base soil. It can support storage tanks, equipment, or tower structures. There are different types including flat plate, plate with thickened columns, and waffle slab. The structural design uses conventional rigid or flexible methods. It involves determining soil pressures, load eccentricities, moment and shear diagrams for strips, punching shear sections, steel reinforcement, and checking stresses. A beam-slab raft foundation design follows the same process as an inverted beam-slab roof.
A group of 16 square piles extends 12 m into stiff clay soil, underlain by rock at 24 m depth. Pile dimensions are 0.3 m x 0.3 m. Undrained shear strength of clay increases linearly from 50 kPa at surface to 150 kPa at rock. Factor of safety for group capacity is 2.5. Determine group capacity and individual pile capacity.
The group capacity is calculated to be 1600 kN. The individual pile capacity is determined to be 100 kN. The factor of safety of 2.5 is then applied to determine the safe load capacity.
This document provides information about the design of strap footings. It begins with an overview of strap footings, noting they are used to connect an eccentrically loaded column footing to an interior column. The strap transmits moment caused by eccentricity to the interior footing to generate uniform soil pressure beneath both footings.
It then outlines the basic considerations for strap footing design: 1) the strap must be rigid, 2) footings should have equal soil pressures to avoid differential settlement, and 3) the strap should be out of contact with soil to avoid soil reactions. Finally, it provides the step-by-step process for designing a strap footing, including proportioning footing dimensions, evaluating soil pressures, designing reinforcement,
This document provides an example of designing a rectangular reinforced concrete beam. It includes calculating the loads, bending moment, required tension reinforcement, checking shear capacity and deflection. For a simply supported beam with a uniformly distributed load, the document calculates the steel reinforcement area required using formulas and tables. It then checks that the beam satisfies requirements for shear capacity, minimum and maximum steel ratios, and deflection. The document also provides an example of designing a doubly reinforced beam.
Footings transfer structural loads from a building to the ground. This document discusses various types of footings and their design procedures. Spread footings are the most common type and are proportioned to have an area large enough that soil and building settlement will be minimized. The general design process involves checking that factored loads are less than the soil's allowable bearing capacity and footing thickness is sufficient to resist punching and beam shear. Reinforcement is calculated and placed to resist bending stresses. Combined and strap footings are also discussed along with their unique design considerations. Brick footings can be used for small residential loads.
Geotechnical Engineering-II [Lec #19: General Bearing Capacity Equation]Muhammad Irfan
Class notes of Geotechnical Engineering course I used to teach at UET Lahore. Feel free to download the slide show.
Anyone looking to modify these files and use them for their own teaching purposes can contact me directly to get hold of editable version.
This document provides an overview of pile foundations, including different types of piles classified by material, length, orientation, and installation method. Piles transfer structural loads to deeper firm soil layers when the top soil is loose, soft, or swelling. Piles are long slender columns that can be driven, bored, or cast in place using materials like concrete, steel, or timber. Driven piles compact the surrounding soil to increase capacity, while cast-in-place piles are constructed by drilling holes and filling with concrete to avoid disturbing soil. The document discusses advantages and disadvantages of different pile types.
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
This document provides details on the design of a rectangular water tank resting on ground. It discusses the analysis done to determine bending moments and tensile forces in the walls. It then shows the step-by-step design of the walls and base slab of a 5m x 4m rectangular tank with 3m depth, reinforced with Fe415 steel bars in M20 concrete. Reinforcement details are calculated and sketched to resist vertical and horizontal bending moments at the wall corners and edges.
This document summarizes Coulomb's earth pressure theory for calculating active and passive lateral earth pressures on retaining walls. It provides derivations of the equations for active and passive pressures in cohesionless soils based on force equilibrium. The key equations given are for the active earth pressure coefficient Ka, which relates the active earth pressure Pa to the vertical stress σv using soil unit weight γ, wall inclination α, and soil friction angle φ.
This document provides information on the design of a concrete beam, including:
1) Key principles in beam design such as determining the effective depth ratio and performing deflection checks.
2) Details on flanged beam design including how the location of the neutral axis affects the process.
3) Procedures for continuous beam design including determining load cases, calculating fixed end moments, and using moment distribution.
This document discusses the design of compression members under uniaxial bending. It notes that columns are rarely under pure axial compression due to eccentricities from rigid frame action or accidental loading. Columns can experience uniaxial or biaxial bending based on the loading. The behavior depends on the relative magnitudes of the bending moment and axial load, which determine the position of the neutral axis. Methods for designing eccentrically loaded short columns include using equations that calculate the neutral axis position and failure mode, or using interaction diagrams that graphically show the safe ranges of moment and axial load.
This document provides measurement quantities for the construction of a guard house for Panicsonic Sdn Bhd. It includes measurements for site clearance, foundation works including piling, pile caps, and column stumps. Reinforcement details and quantities are also provided for pile caps and column stumps. The document is organized by construction stage and provides dimensions, calculations, and quantities for various elements of the project.
This document summarizes the design of a reinforced concrete overhead water tank located in Kalyani, West Bengal, India to serve a population of 1500 people. Key aspects of the design include a diameter of 12 meters, total height of 5 meters, capacity of 540000 liters, and a raft foundation. Load calculations and analysis of the dome shape determine that the meridional and hoop stresses are within code limits for the minimum M30 grade concrete. Nominal tensile reinforcement of 6-8mm bars at 180mm centers in both directions is sufficient. Design codes and references used are cited.
This document provides an overview of mat foundations. It discusses common types of mat foundations including flat plate, flat plate thickened under columns, beams and slab, and slab with basement walls. It describes how to calculate the bearing capacity of mat foundations and differential settlement. Methods for structural design of mat foundations are presented, including the conventional rigid method and approximate flexible method. Examples are provided to illustrate how to design combined footings, calculate bearing capacity, and structurally design mat foundations.
This document provides details on the design of a continuous one-way reinforced concrete slab. It includes minimum thickness requirements, equations for calculating moments and shear, maximum reinforcement ratios, and minimum reinforcement ratios. An example is then provided to demonstrate the design process. The slab is designed to have a thickness of 6 inches with 0.39 in2/ft of tension reinforcement in the negative moment region and 0.33 in2/ft in the positive moment region.
This test measures the compressive strength of concrete cubes made and cured according to specific standards. It provides a measure of quality control by testing one property, compressive strength, but results can vary depending on test conditions like specimen size and loading rate. The document outlines how to conduct compression tests on concrete cubes to determine if the concrete meets design specifications. Cubes are made, cured, weighed, and tested for compressive strength at various ages to see how strength develops over time. Detailed procedures are provided for casting, curing, operating the compression machine, and analyzing results.
1. The document discusses the design and analysis of storage reservoirs and overhead tanks. It covers various types of tanks, design considerations for concrete mixes, crack development remedies, permissible stresses, and reinforcement requirements.
2. Methods for analyzing circular and rectangular tanks are presented. For circular tanks, designs consider rigid versus flexible joints with the base slab. Approximate methods analyze the bottom portion as cantilever and the rest as resisting pressure through horizontal forces.
3. Rectangular tank analysis depends on the length-breadth ratio, treating short walls as bending horizontally between long walls which transfer pressure as tension.
This document provides an overview of analysis and design methods for concrete slabs, including:
1. Elastic analysis methods like grillage analysis and finite element analysis can be used to determine moments and shear forces in slabs.
2. Yield line theory is an alternative plastic/ultimate limit state approach for determining the ultimate load capacity of ductile concrete slabs. It involves assuming yield line patterns that divide the slab into rigid regions and equating external and internal work.
3. Examples are provided to illustrate yield line analysis for one-way spanning slabs and rectangular two-way slabs. Conventions, assumptions, and calculation procedures are explained.
The document provides information about a 21 meter long prestressed concrete pile driven into sand. The pile has an allowable working load of 502 kN, with an octagonal cross-section of 0.356 meters diameter and area of 0.1045 m^2. Skin resistance supports 350 kN of the load and point bearing the rest. The document requests calculating the elastic settlement of the pile given its properties, the load distribution, and soil parameters.
This document provides information on Indian Standard IS:2911 regarding the design and construction of pile foundations. It outlines the necessary members of the committee working on revising the standard. The standard covers driven precast concrete piles, providing guidance on pile design, construction methods, site investigation needs, and other relevant details. It aims to incorporate recent developments in pile foundation engineering practices in India.
1) This document describes the design of a residential building located in Sirumalai, Dindigul district. It is a G+2 storied building located in a congested area without setbacks.
2) The methodology section outlines the process of drawing plans, locating columns and beams, applying dimensions, calculating loads, analyzing shear and bending moments, identifying critical structural elements, and designing the slab, beams, columns, and footings.
3) Key aspects of the design include the load calculations, analysis of the critical frame, design of the slab, beams, columns, and edge and corner footings. Reinforcement is designed according to code provisions.
Circular slabs are commonly used as roofs or floors with a circular plan, such as water tanks. They experience bending stresses in two perpendicular directions - radially and circumferentially. Reinforcement is provided as a mesh of bars with equal cross-sectional area in both directions. Near the edges, additional radial and circumferential reinforcement may be needed if edge stresses are significant. Circular slabs are analyzed based on elastic theory, and deflect into a saucer shape under uniform loads, developing tensile and compressive stresses on the convex and concave surfaces respectively. Reinforcement must be provided in both radial and circumferential directions near the convex surface.
This document discusses different types of retaining walls and their design considerations. It describes:
1. Gravity, cantilever, counterfort, and buttress retaining wall types based on their structural components and typical height ranges.
2. Design considerations for retaining walls including stability against overturning, sliding, and settlement; drainage; and structural design basis using load and safety factors.
3. An example problem showing calculations for earth pressure, restoring moments, and checking stability of a gravity wall.
The document compares the design of an Intze water tank using membrane design and continuity analysis methods. Membrane design assumes members act independently and are only subjected to direct stresses, while continuity analysis considers restraint at edges causing secondary stresses. For a 9 lakh liter tank, continuity analysis results in higher hoop forces, moments, and steel reinforcement compared to membrane design. A similar trend is seen for a 6 lakh liter tank, with continuity analysis giving higher stresses and reinforcement.
Geotechnical Engineering-II [Lec #19: General Bearing Capacity Equation]Muhammad Irfan
Class notes of Geotechnical Engineering course I used to teach at UET Lahore. Feel free to download the slide show.
Anyone looking to modify these files and use them for their own teaching purposes can contact me directly to get hold of editable version.
This document provides an overview of pile foundations, including different types of piles classified by material, length, orientation, and installation method. Piles transfer structural loads to deeper firm soil layers when the top soil is loose, soft, or swelling. Piles are long slender columns that can be driven, bored, or cast in place using materials like concrete, steel, or timber. Driven piles compact the surrounding soil to increase capacity, while cast-in-place piles are constructed by drilling holes and filling with concrete to avoid disturbing soil. The document discusses advantages and disadvantages of different pile types.
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
This document provides details on the design of a rectangular water tank resting on ground. It discusses the analysis done to determine bending moments and tensile forces in the walls. It then shows the step-by-step design of the walls and base slab of a 5m x 4m rectangular tank with 3m depth, reinforced with Fe415 steel bars in M20 concrete. Reinforcement details are calculated and sketched to resist vertical and horizontal bending moments at the wall corners and edges.
This document summarizes Coulomb's earth pressure theory for calculating active and passive lateral earth pressures on retaining walls. It provides derivations of the equations for active and passive pressures in cohesionless soils based on force equilibrium. The key equations given are for the active earth pressure coefficient Ka, which relates the active earth pressure Pa to the vertical stress σv using soil unit weight γ, wall inclination α, and soil friction angle φ.
This document provides information on the design of a concrete beam, including:
1) Key principles in beam design such as determining the effective depth ratio and performing deflection checks.
2) Details on flanged beam design including how the location of the neutral axis affects the process.
3) Procedures for continuous beam design including determining load cases, calculating fixed end moments, and using moment distribution.
This document discusses the design of compression members under uniaxial bending. It notes that columns are rarely under pure axial compression due to eccentricities from rigid frame action or accidental loading. Columns can experience uniaxial or biaxial bending based on the loading. The behavior depends on the relative magnitudes of the bending moment and axial load, which determine the position of the neutral axis. Methods for designing eccentrically loaded short columns include using equations that calculate the neutral axis position and failure mode, or using interaction diagrams that graphically show the safe ranges of moment and axial load.
This document provides measurement quantities for the construction of a guard house for Panicsonic Sdn Bhd. It includes measurements for site clearance, foundation works including piling, pile caps, and column stumps. Reinforcement details and quantities are also provided for pile caps and column stumps. The document is organized by construction stage and provides dimensions, calculations, and quantities for various elements of the project.
This document summarizes the design of a reinforced concrete overhead water tank located in Kalyani, West Bengal, India to serve a population of 1500 people. Key aspects of the design include a diameter of 12 meters, total height of 5 meters, capacity of 540000 liters, and a raft foundation. Load calculations and analysis of the dome shape determine that the meridional and hoop stresses are within code limits for the minimum M30 grade concrete. Nominal tensile reinforcement of 6-8mm bars at 180mm centers in both directions is sufficient. Design codes and references used are cited.
This document provides an overview of mat foundations. It discusses common types of mat foundations including flat plate, flat plate thickened under columns, beams and slab, and slab with basement walls. It describes how to calculate the bearing capacity of mat foundations and differential settlement. Methods for structural design of mat foundations are presented, including the conventional rigid method and approximate flexible method. Examples are provided to illustrate how to design combined footings, calculate bearing capacity, and structurally design mat foundations.
This document provides details on the design of a continuous one-way reinforced concrete slab. It includes minimum thickness requirements, equations for calculating moments and shear, maximum reinforcement ratios, and minimum reinforcement ratios. An example is then provided to demonstrate the design process. The slab is designed to have a thickness of 6 inches with 0.39 in2/ft of tension reinforcement in the negative moment region and 0.33 in2/ft in the positive moment region.
This test measures the compressive strength of concrete cubes made and cured according to specific standards. It provides a measure of quality control by testing one property, compressive strength, but results can vary depending on test conditions like specimen size and loading rate. The document outlines how to conduct compression tests on concrete cubes to determine if the concrete meets design specifications. Cubes are made, cured, weighed, and tested for compressive strength at various ages to see how strength develops over time. Detailed procedures are provided for casting, curing, operating the compression machine, and analyzing results.
1. The document discusses the design and analysis of storage reservoirs and overhead tanks. It covers various types of tanks, design considerations for concrete mixes, crack development remedies, permissible stresses, and reinforcement requirements.
2. Methods for analyzing circular and rectangular tanks are presented. For circular tanks, designs consider rigid versus flexible joints with the base slab. Approximate methods analyze the bottom portion as cantilever and the rest as resisting pressure through horizontal forces.
3. Rectangular tank analysis depends on the length-breadth ratio, treating short walls as bending horizontally between long walls which transfer pressure as tension.
This document provides an overview of analysis and design methods for concrete slabs, including:
1. Elastic analysis methods like grillage analysis and finite element analysis can be used to determine moments and shear forces in slabs.
2. Yield line theory is an alternative plastic/ultimate limit state approach for determining the ultimate load capacity of ductile concrete slabs. It involves assuming yield line patterns that divide the slab into rigid regions and equating external and internal work.
3. Examples are provided to illustrate yield line analysis for one-way spanning slabs and rectangular two-way slabs. Conventions, assumptions, and calculation procedures are explained.
The document provides information about a 21 meter long prestressed concrete pile driven into sand. The pile has an allowable working load of 502 kN, with an octagonal cross-section of 0.356 meters diameter and area of 0.1045 m^2. Skin resistance supports 350 kN of the load and point bearing the rest. The document requests calculating the elastic settlement of the pile given its properties, the load distribution, and soil parameters.
This document provides information on Indian Standard IS:2911 regarding the design and construction of pile foundations. It outlines the necessary members of the committee working on revising the standard. The standard covers driven precast concrete piles, providing guidance on pile design, construction methods, site investigation needs, and other relevant details. It aims to incorporate recent developments in pile foundation engineering practices in India.
1) This document describes the design of a residential building located in Sirumalai, Dindigul district. It is a G+2 storied building located in a congested area without setbacks.
2) The methodology section outlines the process of drawing plans, locating columns and beams, applying dimensions, calculating loads, analyzing shear and bending moments, identifying critical structural elements, and designing the slab, beams, columns, and footings.
3) Key aspects of the design include the load calculations, analysis of the critical frame, design of the slab, beams, columns, and edge and corner footings. Reinforcement is designed according to code provisions.
Circular slabs are commonly used as roofs or floors with a circular plan, such as water tanks. They experience bending stresses in two perpendicular directions - radially and circumferentially. Reinforcement is provided as a mesh of bars with equal cross-sectional area in both directions. Near the edges, additional radial and circumferential reinforcement may be needed if edge stresses are significant. Circular slabs are analyzed based on elastic theory, and deflect into a saucer shape under uniform loads, developing tensile and compressive stresses on the convex and concave surfaces respectively. Reinforcement must be provided in both radial and circumferential directions near the convex surface.
This document discusses different types of retaining walls and their design considerations. It describes:
1. Gravity, cantilever, counterfort, and buttress retaining wall types based on their structural components and typical height ranges.
2. Design considerations for retaining walls including stability against overturning, sliding, and settlement; drainage; and structural design basis using load and safety factors.
3. An example problem showing calculations for earth pressure, restoring moments, and checking stability of a gravity wall.
The document compares the design of an Intze water tank using membrane design and continuity analysis methods. Membrane design assumes members act independently and are only subjected to direct stresses, while continuity analysis considers restraint at edges causing secondary stresses. For a 9 lakh liter tank, continuity analysis results in higher hoop forces, moments, and steel reinforcement compared to membrane design. A similar trend is seen for a 6 lakh liter tank, with continuity analysis giving higher stresses and reinforcement.
Pile foundations are commonly used when soil conditions require deep foundations, such as with compressible, waterlogged, or deep soils. There are various types of piles classified by function (e.g. end bearing, friction, tension), material (e.g. concrete, timber, steel), and installation method (e.g. driven, cast-in-place). The load carrying capacity of piles can be determined through dynamic formulas, static formulas, load tests, or penetration tests. Factors like pile length, structure characteristics, material availability, loading types, and costs must be considered for proper pile selection.
This document provides information about pile foundations. Pile foundations are used when the soil cannot support building loads and piles are driven deep into the ground until they reach a bearing stratum. Piles can be made of timber, concrete, or steel. They transfer loads from the building to the stronger subsurface layer. The document discusses different types of piles including end bearing and friction piles and explains how pile caps are reinforced to resist tensile and shear forces from heavy loads. Diagrams show how pile foundations are arranged and how piles transmit loads into the ground.
The pile foundation uses piles to support walls, piers, and other structures. Piles can be placed individually or in clusters. Piles are used when loose soil extends to great depths, and transfer structural loads to harder soils below through end bearing and side friction. Common pile materials include timber, steel, and concrete. Piles can be load bearing, transmitting loads through end bearing and side friction, or non-load bearing, used as retaining walls or sheeting. Pile capacity is assessed through field load tests or theoretical calculations based on soil properties.
Memo 55b-rvk-101-rekommended-reinforcement-patternS.s. Lee
This document provides recommended reinforcement patterns for concrete slabs with RVK 101 units.
Figure 1 shows reinforcement for slabs 265mm thick with a large edge distance of over 450mm. Figures 2 and 3 show reinforcement for slabs with smaller edge distances, down to 180mm. Reinforcement includes stirrups along edges and transverse bars. Load limits for different slab thicknesses and edge distances are provided in Figure 5. General comments address placement of reinforcement, anchoring, and tolerances.
Memo 55c-tss-41-rekommended-reinforcement-patternS.s. Lee
The document provides recommendations for reinforcing concrete slabs with TSS 41 units embedded in them. Figure 1 shows the recommended reinforcement pattern for slabs with an edge distance over 300mm from the unit. Figures 2 and 3 show patterns for closer edge distances. The reinforcement consists of stirrups connecting the unit to rebar in the slab. Comments provide details on rebar sizes, spacing, and intended load transfers. Edge reinforcement is also recommended continuously along all edges according to code standards. Load limits for the slab vary based on thickness and edge distance.
Design of Beam- RCC Singly Reinforced BeamSHAZEBALIKHAN1
Concrete beams are an essential part of civil structures. Learn the design basis, calculations for sizing, tension reinforcement, and shear reinforcement for a concrete beam.
The document discusses the design requirements for lacing, battening, and column bases according to IS 800-2007. It provides details on:
- Two types of lacing systems - single and double
- Design requirements for lacing including angle of inclination, slenderness ratio, effective lacing length, bar width and thickness
- Design of battening including number of battens, spacing, thickness, effective depth, and transverse shear
- Minimum thickness requirements for rectangular slab column bases
It also provides an example problem demonstrating the design of a slab base foundation for a column.
The document discusses buckling of columns under axial compression. It describes:
1) Different buckling theories including elastic buckling, inelastic buckling using tangent modulus theory and reduced modulus theory. Shanley's theory accounts for the effect of transverse displacement.
2) Factors affecting buckling strength including end conditions, initial crookedness, and residual stresses. Effective length accounts for end restraint.
3) Local buckling of thin plate elements can reduce the column's strength before its calculated buckling strength is reached. Flange and web buckling must be prevented.
Because of torsion, the beam fails in diagonal tension forming the spiral cracks around the beam. Warping of the section does not allow a plane section to remain as plane after twisting. Clause 41 of IS 456:2000 provides the provisions for
the design of torsional reinforcements. The design rules for torsion are based on the equivalent moment.
There are three main steps to designing a column splice:
1. Determine loads on the splice from axial, bending and shear forces. For axial loads, splices are designed to carry 50% of the load for machined ends or 100% for non-machined ends.
2. Design the splice plates to resist the loads using the yield stress as the design strength. Plate size is calculated based on load and stress.
3. Determine the number and size of bolts required based on the plate load capacity and bolt strengths in shear or bearing. Splice widths match the column and minimum plate thickness is 6mm.
good for engineering students
to get deep knowledge about design of singly reinforced beam by working stress method.
see and learn about rcc structure....................................................
Design of short columns using helical reinforcementshivam gautam
Helical reinforcement, also known as spiral reinforcement, is used in circular concrete columns. It consists of longitudinal bars enclosed within a continuously wound spiral reinforcement. Helical reinforcement is sometimes designed instead of normal links for columns because it provides increased strength and ductility. The spiral reinforcement acts compositely with the concrete core and allows the column to sustain higher loads than those with normal links. It also minimizes the risk of stirrups opening during seismic events. The document then provides details on the design of helical reinforcement for short concrete columns, including governing equations and an example problem.
This document summarizes design considerations for shear in reinforced concrete structures. It discusses shear strength provided by concrete alone (Vc), shear strength provided by shear reinforcement (Vs), and methods for calculating total shear strength (Vn). It also covers requirements for shear reinforcement spacing and minimum amounts. Design aids are presented for calculating shear capacity of beams, slabs, and members under combined shear and torsion.
This document describes a study analyzing the seismic performance of a 2-story concentrically braced frame (CBF) building with and without dissipative single-pin connections using OpenSees software. It first provides details on the design and modeling of the single-pin connection, which is intended to improve the seismic response of CBFs by allowing full development of brace compressive strength. It then describes the OpenSees model of the connection and calibration against experimental data. Finally, it outlines the numerical analysis conducted, including design of the CBF building based on Canadian standards and comparison of the seismic response of the building with and without pin connections.
1. The document discusses the design of one-way reinforced concrete slabs according to Indian code IS 456:2000.
2. It defines one-way slabs as edge supported slabs spanning in one direction with a ratio of long to short span greater than or equal to 2.
3. The main considerations for slab design discussed are effective span, deflection control, reinforcement requirements including minimum area, maximum bar diameter and cover, and load calculations.
The document provides the step-by-step process for designing a cotter joint to connect two steel rods subjected to an axial tensile force. It involves selecting the material (plain carbon steel), selecting a factor of safety of 6 for the rods and ends and 4 for the cotter, calculating permissible stresses, and designing the spigot, socket, and cotter dimensions based on equations considering failure by tension, crushing, shear, and bending. The key dimensions designed and specified are the diameters of the rod, spigot, socket ends and collars, thicknesses of the spigot and socket collars, length and width of the cotter.
This document discusses tension members in structural engineering. It defines tension members as linear members that experience axial forces that elongate or stretch the member. Examples given include ropes, ties in trusses, suspenders in bridges. The document discusses the types of cross-sections used for tension members like angles, channels, rods. It also discusses the calculation of net effective sectional area and provides examples. Other topics covered include types of failures in tension members, design strength calculations, limiting slenderness ratios, tension splices, and lug angles.
Design of column base plates anchor boltKhaled Eid
This document discusses the design of column base plates and steel anchorage to concrete. It covers base plate materials and design for different load cases including axial, moment, and shear loads. It also discusses anchor rod types, materials, and design for tension and shear loading based on calculations of the steel and concrete breakout strengths according to building codes.
This document provides definitions and design considerations for singly reinforced concrete beams. It defines key terms like overall depth, effective depth, clear cover, and neutral axis. It explains that a singly reinforced beam only has steel reinforcement in the tensile zone below the neutral axis. Beam design aims to select member dimensions and reinforcement amount to safely support loads over the structure's lifetime. Singly reinforced beams can be designed as balanced, under-reinforced, or over-reinforced sections depending on steel reinforcement ratio. Basic design rules cover effective span, depth, bearing capacity, deflection limits, and reinforcement requirements.
The document provides information on the design of singly reinforced concrete beams. It defines key terms like overall depth, effective depth, clear cover, neutral axis, and lever arm. It describes the types of beam sections as balanced, under-reinforced and over-reinforced. Under-reinforced beams are designed for economy and provide warning before failure, while over-reinforced beams fail suddenly from concrete overstress. The procedure for designing singly reinforced beams using the working stress method is outlined in steps involving calculating design constants, assuming beam dimensions, determining loads, finding steel area required, and checking for shear and deflection requirements.
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1. PILE CAP DESIGN
PILE CAP:-
A reinforced concrete slab or block which interconnects a group of piles and acts
as a medium to transmit the load from wall or column to the Piles is called a Pile
Cap. The Pile cap should normally be rigid so as to distribute the forces equally on
the piles of a group. In general it is designed like a footing on soil but with the
difference that instead of uniform reaction from the soil, the reactions in this case
are concentrated either point loads or distributed.
As per IS 2911 (Part I/ Sec 3) -2010, the pile cap may be designed by assuming
that the load from column is dispersed at 45˚ from the top of the cap up to the mid
depth of the pile cap from the base of the column or pedestal. The reaction from
piles may also be taken to be distributed at 45˚ from the edge of the pile, up to the
mid depth of the pile cap. On this basis the maximum bending moment and shear
forces should be worked out at critical sections.
ASSUMPTIONS INVOLVED IN THE DESIGN OF PILE CAPS:-
(i) Pile cap is perfectly rigid.
(ii) Pile heads are hinged to the pile cap and hence no bending moment is
transmitted to piles from pile caps.
(iii) Since the piles are short and elastic columns, the deformations and stress
distribution are planer.
DESIGN PARAMETERS OF PILE CAPS:-
(i) Shape of pile cap.
(ii) Depth of pile cap.
(iii) Amount of steel to be provided.
(iv) Arrangement of reinforcement.
2. (i) Shape of pile cap:-
Whittle and Beattie have developed through computer program the
relationship between dimension of pile cap and the size of the pile.
The minimum spacing of piles permitted from soil mechanics depends on the
type and end conditions. CP 2004 requires a minimum centre- to –centre
spacing of twice the diameter of the piles for end bearing and three times the
diameter for friction piles. IS 2911 part1, sections 1 and 2 recommended a
minimum spacing of two and half times the diameter of the pile for both driven
cast in situ and bored cast in situ piles.
For accommodating deviations in driving of piles, the size of the pile cap is
made 300 mm more than the outer- to outer distance of the exterior piles. (150
mm on either side).
The plan dimension of the pile cap is based on the fact that the actual final
position of piles can be in construction up to 100 mm out of line from the
theoretical centre lines. Pile caps should be made very large to accommodate these
deviations. In practice, pile caps are extended as much as 150 mm beyond the
outer face of the piles.
Standard Pile Caps:
s-spacing of pile = F x hp where
hp = diameter of pile in mm
F = spacing factor= centre to centre spacing
Pile diameter
3. (ii) Depth of Pile Cap :-
The thickness of the Pile Cap is fixed such that it is adequate to resist shear
without shear reinforcement and the bars projecting from the piles and the
dowel bars for the column can be provided adequate bond length. As per IS
456- 2000, the minimum thickness on top of piles should not be less than 300
mm. Pile cap depth should be kept on the high side to effect economy in the
consumption of steel and also to provide adequate rigidity to pile cap. Generally,
pile cap thickness should not be less than 500 mm which may be reduced to 300
mm at the free edges. For pile caps to be rigid, pile cap has to be quite deep
with 600 mm as the minimum depth. As a guide line the formula given in
Reinforced concrete by Reynolds may be followed.
For Pile dia > 550 mm,
Pile cap depth (h) = (2 hp + 100)mm
For Pile dia ≥ 550 mm,
h= ⅓ x( 8 hp + 600) mm
Pile Dia
hp (mm)
300 350 400 450 500 550 600 750
Pile Cap
depth
h(mm)
700 800 900 1000 1100 1200 1400 1800
(i) Amount of steel to be provided :-
The Pile Cap has to be designed either truss theory or beam theory.
Although, the pile caps are assumed to act as a simply supported beam
and are designed for the usual condition of bending and shear, their
tendency is to fail by bursting due to high principal tension and they will
therefore always require a cage of reinforcement in three dimensions to
resist this tendency.
The main reinforcement is usually bend (full bend) and extended
for full depth of pile cap to fulfill the check for development length.
Though IS 456-2000 is silent on specifying the minimum reinforcement, a
minimum reinforcement of 0.15 % BD for main reinforcement and 0.12
% BD for secondary reinforcement may be provided as per clause
3 .11.4.1 and 2 of CP 110 code). For bursting (horizontal binders) it is
4. suggested that 25 % of the main reinforcement (usually 12 Φ RTS at
150 mm c/c) shall be used.
Cover :- A cover of 75 mm is usually provided for the pile cap surfaces in
contact with earth and 60 mm against blinding concrete of 75 to 100 mm
thick. In marine situations the cover should be increased to a minimum
of 80 mm.
DESIGN OF PILE CAP BASED ON TRUSS THEORY:
The truss theory applied to pile caps with up to 5 piles. In this method the
load from the column is transmitted to the piles by inclined thrust and the tie
necessary to maintain equilibrium is provided by reinforcement. (Steel acts as
tension chord and concrete as diagonal struts).
If the Ultimate load on the column is N and we have two piles the load on each
pile is N/2.
From the diagram of forces T = l
(N/2) d
i.e. T = N l/2d
Area of reinforcement required = Nl/ (2d x 0.87 fy )
In the simple frame described above, the dimensions of the columns have been
ignored. If the Column is square of side 2a,
T = N (3l
2
– a
2
)
6 ld
In truss theory, it has usually been the practice to band the
reinforcement along the lines joining the piles. The code now suggests that this
method of banding is only necessary if the piles are spaced at more than
3 times the pile dia. For the more normal spacing of 3 times the pile dia the total
reinforcement forming the tie force in one direction can be distributed uniformly
across the cap with a three- pile cap designed on the truss theory, it is difficult
to see how this can be done and it is suggested that the reinforcement is
banded along the centre lines joining the piles.
In the case of pile caps designed using the truss theory it is
suggested that the effective depth is approximately half the distance between
the centre of piles. This means the truss has an angle of approximately 45˚.
5. Allowable shear resistance is given by
N= 2 (d hp ) 2 ζc (d/av) + (b- 2 hp ) ζc bd where ζc = design shear strength of
concrete.
av = 0.5(l- b) where l= c/c of piles & b = width of column.
The section should be safe without extra shear reinforcement.
Truss theory design can be done using Table 194 of Reynould’s hand book.
6. Beam theory :- When (av / d) ratio is more than 2 as in shallow pile cap or
with the arrangement of 6 or more piles, bending action is more predominant
than truss action. In this case the pile cap is designed as a normal beam for
bending moment and shear. The pile cap area is divided into a framework of
rectangular beam depending on the geometry of the pile group. The width of the
beam is taken as equal to the width of the pile. The beam may be simply
supported or continuous.
The reinforcement is evenly distributed or concentrated. The reaction from
the pile is taken as distributed at 45˚ from the edge of the pile cap up to the
mid- depth of the pile cap. The maximum bending moment and shear force are
calculated on this basis. However, it is much easier to consider the loads as
concentrated loads and calculate the B.M. and S.F. The depth should be such
that no extra shear reinforcement is necessary for the section.
7. Practical Aspects on Pile cap Design:
The structural design of a pile cap is similar to the design of spread footing. The load
acting on the pile cap from the superstructure and piles are resisted by the
developments of bending moment and shear force in the pile cap.
Codal provisions made in IS 2911(Part 1/sec3)-2010 :
1. The size of the pile cap is fixed in such way that it has clear overhang beyond
the outermost pile not less than 100mm, but preferably 150mm.
2. It should be deep enough to allow the necessary overlap of reinforcements from
column and piles.
3. The clear cover to the main reinforcement should not be less than 40mm.
4. The span to thickness ratio of the cap should not be more than 5 so that pile cap
is rigid enough to distribute the load uniformly to the piles.
5. Generally, its thickness should not be less than 500mm which may be reduced to
300mm at the free edges.
6. The piles should atleast 50mm into the pile cap.
7. A leveling course of not less 75mm thick concrete should be provided under the
pile cap.
Design Aspects :-
The reaction from the piles under the concentric axial load on the cap is
assumed equal and is determined by,
Pp = Q/n ----- (1)
where Q = concentric axial load on the cap
n = Number of Piles
When the Pile cap is eccentrically loaded or subjected to a load and moments
then the reactions from the Piles are determined as
Pp = Q/n +/- My x +/- Mx y ----- (2) where
∑x2
∑y2
Mx, My = moments with respect to x and y axes.
X, y = distances from y and x axes to the Piles.
8. The critical section for bending moments and bond shall be calculated at the
face of column or pedestal.
The critical section for two way shear (Punching shear) will be at a distance d/2
from face of column or pedestal.
One way shear is checked at a distance of d/2 from the face of the column.
The Clause 34.2.4.2 of IS 456 – 2000 states the following :-
“In computing the external shear or any section through a footing supported on
Piles, the entire reaction from any pile of diameter Dp whose centre is located
Dp/2 or more outside the section shall be assumed as producing shear on the
section; the reaction from any Pile whose centre is located Dp/2 or more inside
the section shall be assumed as producing no shear on the section. For
intermediate positions of the pile centre, the position of pile reaction to be
assumed as producing shear on the section shall be based on straight line
interpolation between full value at Dp/2 outside the section and zero value at
Dp/2 inside the section.”
In computing external shear on any section the entire (100%) reaction of the
Pile shall be taken if the pile centre is located at 150 mm or more outside the
section. The pile reaction will produce no shear (0%) if the pile centre is located
at 150 mm or more inside the section. A linear interpolation shall be made for
intermediate values of the pile centre.
Let the centre of the pile be located at ‘x’ from the face of the column. Let
‘d’ be the effective depth of the pile cap. Then the critical section is located at
d/2 from face of the column.
If pile centre is located at (d/2 –x) outside the critical section when x
< d/2.
If x > d/2, the expression (d/2-x) yields negative value indicating that
the pile centre is located at (x-d/2) inside the section. When
(d/2-x), outside is true for other case.
Let the fraction of pile reaction inducing shear be f R where R is the pile
reaction.
Rule for checking one way shear,
f = 150 +(x-d/2)
300
where x and d are in millimeters.
9. DESIGN OF TWO PILE CAP
DATA:-
Pile Diameter : 400 mm
Spacing of piles 2 hp = 2 x 400 : 800 mm
Column Dimension B x D : 300 x 450 mm
Factored Load : 1072.8 KN
Factored Moment Mxu :51.29 KN.m
Safe Load on Single Pile :500KN
Concrete Mix : M20
Steel Grade : Fe 415
DESIGN : -
1. Pile Cap Dimension :
Breadth of Pile Cap = C/c of Pile + hp /2+ 150 + hp /2 + 150
= 800 + 400/2+ 150 +400/2+ 150 =1500 mm
Width of pile cap = hp + 150 + 150 = 700 mm
Depth of Pile cap = 2 hp + 100 = 2 x 400 + 100 = 900 mm.
10. 2. Check for Pile Load capacity :-
Total factored axial compressive load
= Pu +/- Mxy +/- Mxx
n ∑y
2
∑x
2
Self weight of Pile Cap = (1.5 x0.7 x 0.9 x 25 ) x1.5 = 35.45 KN
Factored load from column Pu = 1072.80 KN
------------
Total Factored Load Pu = 1108.25 KN
-------------
No. of Piles along one side of axis = 2
y coordinate of Pile cap = 0.4 m
Mx = Moment about x axis = 51.29 KN.m
Compressive load in A1 & A2 about x – x axis
= 1108.25 + 51.29 x 0.4
2 2 x 0.4
2
= 554.13 + 64.11
=618.24 KN
Design working load = 618.24 /1.5 = 412.16 KN < Safe Load on Pile i.e
500KN. O.K.
3. Bending Moment :-
Factored Moment in section Y-Y
Mu = 618.24 x (0.8-0.3)= 154.56 KN.m
2
4. Check for effective depth :
Mu = 0.138 fck b d
2
= 154.56 x 10
6
d required = √ (154.56 x 10
6
) / 2.76 x700 =282.84 mm
D provided = 900 mm
d available = 900 – 60 -12- 6 = 822 mm > d required i.e. 282.84 mm
5. Check for Punching Shear (Two way shear) : -
Punching shear at a distance d/2 (i.e.822/2= 411mm) from face of column
= 1072.80 KN
The critical section of punching comes the centre of pile.
11. Hence the net load is to be taken. However the depth is checked for factored
axial load from column = 1072.80 KN
b= 700 x 822 mm
d= 822 mm
Perimeter of critical section = 2 (700 + 822) = 3044 mm
Punching shear stress = 1072.80 x 10
3
= 0. 43 N/mm
2
3044 x 822
Allowable shear stress for M20
= 0.25 √fck = 0.25 √20 = 1.12 N/mm
2
Hence safe.
6. Main Reinforcement : -
Mu = 154.56 x 10
6
KN.m
K = Mu / bd
2
= 154.56 x 10
6
= 0.33
700 x 822
2
Pt from Table 2 of Design Aid=0.11
Minimum Ast = 0.12 x 700 x 822 = 690.48 mm
2
100
Provide 7 Nos. 12 Φ RTS at bottom on both ways.
(Ast = 791 mm
2
> 690.48 mm
2
)
Reinforcement at top :-
Minimum Ast = 0.12 x 700 x 822 = 690.48 mm
2
100
Provide 7 Nos. 12 mm Dia RTS at top .
(Ast = 791 mm
2
> 690.48 mm
2
)
7. Check for one way shear :-
Maximum Shear force at face of column = 618.24 KN
Shear stress = 618.24 x 10
3
= 1.07 N/mm
2
700 x 822
For Pt = 0.20%
ζc from Table 61 of Design Aid to IS 456 -1978 = 0.33 N /mm
2
Shear to be carried by stirrups shear