This document presents the results of a parametric study to optimize the design of post-tensioned concrete box-girder pedestrian bridges with main spans ranging from 30 to 60 meters. An optimization algorithm called SAMO2 was used to minimize the cost by varying 33 design variables related to geometry, materials, and construction. The optimal solutions showed that depth and number of prestressing strands correlated with main span length, while slab thicknesses generally took minimum allowed values. Increasing the main span by 1 meter on average increased total cost by 6.38 euros per square meter. Concrete strength varied between 35 to 55 MPa but tended to increase with longer spans.
Three dimensional finite element modeling of pervious concrete pavementeSAT Journals
Abstract Pervious concrete has the unique characteristic of allowing water to pass through its porous matrix. . Pervious concrete pavement systems usually have three main layers, pervious concrete on the top, a subbase layer of aggregate for water storage in the middle and the subgrade (soil) layer below. Finite element modeling of this novel material is challenging due to its complex porous characteristics. In this paper, a method has been proposed to model pervious concrete pavement using finite element methods, which includes a modified approach to capture the unique vertical porosity distribution in the pervious concrete layer by averaging the distribution in three distinct vertical sections. The mechanical properties of the pervious concrete layer are assumed to vary along its depth since the porosity of the pervious concrete also varies with depth. ABAQUS, a general-purpose finite element software package was used to develop the model and perform the analysis. The model was validated through a convergence study, and in comparison with the analytical theory of tensile stress and deflection for traditional concrete pavement. In addition, the significance of the porosity distribution model was validated by comparing the results from EverFE – a specific software for pavement structure analysis. It was found that there is significant difference in tensile stress if modeled using the modified vertical porosity distribution in the previous concrete layer to more fully capture its vertical porosity distribution, as compared to an averaged porosity model in the previous concrete layer. It was also noted that compressive stress demand may have increased importance for pervious concrete, but only for highly porous applications which are not commonly used. Keywords: pervious concrete, vertical porosity, finite element, critical loading, stress, deflection
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
Applications of FEM in Geotechnical Engineering / State-of-the-ArtDr Mazin Alhamrany
This presentation supposed to be given during the 1st Iraqi International Conference on Geotechnical Engineering (ICGE) - Baghdad - 17-19 February 2020. I am uploading this document on LinkedIn as a contribution providing geotechnical engineers an insight for the earlier, recent and "potential" future applications of FEM in the field of Geotechnical Engineering. With my best wishes to the Iraqi Geotechnical Society.
Innovative solutions for complex geotechnical and tunnelling projects, april ...Dr Mazin Alhamrany
Dr Mazin Alhamrany has experience of more than 25 years in the field of Geotechnical and Tunneling Engineering. Dr Mazin is specialist in the field of applications of Finite Element Method for tackling soil-structure interaction problems. He is a highly experienced in 2D and 3D Finite Element Modelling, using advanced soil models, to simulate construction staging and soil-structure interaction to produce buildable economic designs and to assess the impact of carrying out engineering activities such as deep excavations on existing adjacent structures. We have a solid reputation in finding innovative solutions for complex geotechnical and tunneling projects.
Numerical Optimization of Shoring Towers for Slab Formwork SystemsIJTET Journal
The usage of Shoring Tower for slab formwork is getting increased due to not only because of flexibility in the assemble and
construction over Prop-Supported Slab Formwork but also the capacity to withstand maximum construction working loads. The Shoring Tower is
generally used for the construction of heavy structures like Bridges, Culverts, staging of Retaining walls, etc. However a comprehensive scale down
of the shoring tower design goes well with the large span and increased slab thickness of conventional buildings. This research focuses primarily on
Analysis, Modelling, Design and Adaptability of shoring tower for slab formwork through computer models and optimized. The different models are
made from the combination of diameter of tubes with slab thickness and also with plywood thickness in Solid Works. Periodic analysis is done in
ANSYS for different load combinations with the variations of slab thickness and plywood thickness will gives the optimized results for the slab
formwork systems.
Three dimensional finite element modeling of pervious concrete pavementeSAT Journals
Abstract Pervious concrete has the unique characteristic of allowing water to pass through its porous matrix. . Pervious concrete pavement systems usually have three main layers, pervious concrete on the top, a subbase layer of aggregate for water storage in the middle and the subgrade (soil) layer below. Finite element modeling of this novel material is challenging due to its complex porous characteristics. In this paper, a method has been proposed to model pervious concrete pavement using finite element methods, which includes a modified approach to capture the unique vertical porosity distribution in the pervious concrete layer by averaging the distribution in three distinct vertical sections. The mechanical properties of the pervious concrete layer are assumed to vary along its depth since the porosity of the pervious concrete also varies with depth. ABAQUS, a general-purpose finite element software package was used to develop the model and perform the analysis. The model was validated through a convergence study, and in comparison with the analytical theory of tensile stress and deflection for traditional concrete pavement. In addition, the significance of the porosity distribution model was validated by comparing the results from EverFE – a specific software for pavement structure analysis. It was found that there is significant difference in tensile stress if modeled using the modified vertical porosity distribution in the previous concrete layer to more fully capture its vertical porosity distribution, as compared to an averaged porosity model in the previous concrete layer. It was also noted that compressive stress demand may have increased importance for pervious concrete, but only for highly porous applications which are not commonly used. Keywords: pervious concrete, vertical porosity, finite element, critical loading, stress, deflection
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
Applications of FEM in Geotechnical Engineering / State-of-the-ArtDr Mazin Alhamrany
This presentation supposed to be given during the 1st Iraqi International Conference on Geotechnical Engineering (ICGE) - Baghdad - 17-19 February 2020. I am uploading this document on LinkedIn as a contribution providing geotechnical engineers an insight for the earlier, recent and "potential" future applications of FEM in the field of Geotechnical Engineering. With my best wishes to the Iraqi Geotechnical Society.
Innovative solutions for complex geotechnical and tunnelling projects, april ...Dr Mazin Alhamrany
Dr Mazin Alhamrany has experience of more than 25 years in the field of Geotechnical and Tunneling Engineering. Dr Mazin is specialist in the field of applications of Finite Element Method for tackling soil-structure interaction problems. He is a highly experienced in 2D and 3D Finite Element Modelling, using advanced soil models, to simulate construction staging and soil-structure interaction to produce buildable economic designs and to assess the impact of carrying out engineering activities such as deep excavations on existing adjacent structures. We have a solid reputation in finding innovative solutions for complex geotechnical and tunneling projects.
Numerical Optimization of Shoring Towers for Slab Formwork SystemsIJTET Journal
The usage of Shoring Tower for slab formwork is getting increased due to not only because of flexibility in the assemble and
construction over Prop-Supported Slab Formwork but also the capacity to withstand maximum construction working loads. The Shoring Tower is
generally used for the construction of heavy structures like Bridges, Culverts, staging of Retaining walls, etc. However a comprehensive scale down
of the shoring tower design goes well with the large span and increased slab thickness of conventional buildings. This research focuses primarily on
Analysis, Modelling, Design and Adaptability of shoring tower for slab formwork through computer models and optimized. The different models are
made from the combination of diameter of tubes with slab thickness and also with plywood thickness in Solid Works. Periodic analysis is done in
ANSYS for different load combinations with the variations of slab thickness and plywood thickness will gives the optimized results for the slab
formwork systems.
Efficiency of vertical drains using finite element method may 2017Dr Mazin Alhamrany
Incorporating one-dimensional bar elements with two-dimensional quadrilateral axisymmetrical elements to tackle problems of consolidation of clay with vertical drains.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Finite element analysis of innovative solutions of precast concrete beamcolum...Franco Bontempi
Especially to precast concrete structure connections are one of the most essential parts. Connections transfer forces between precast members, so the interaction between precast units is obtained. They are generally the
weakest link in the structure. An acceptable performance of precast concrete structure depends especially on the
appropriate kind of connections choice, adequate detailing of components and design of the connections is fundamental. It is interesting to study the behavior of connecting elements and to compare different solutions of ductile connections for precast concrete structures in case of horizontal applied force and vertical imposed displacement, as well as those produced by hazards situation, like that earthquake and explosion, whereby topics of structure robustness are carried out. The case of study is an innovative dissipative system of connection between precast concrete elements, usable for buildings and bridges, the investigation of these topics is carried out by F.E.A. by program DIANA with comparison with results obtained independently with ASTER.
Effect of infill walls on the seismic performance of the multistoried buildingseSAT Journals
Abstract The most commonly used structural system in our country for almost all types of building are multi-storey reinforced concrete frames with masonry infills. Therefore it is essential to understand the seismic behaviour of these structures when subjected to lateral forces. Several research works has been done on the masonry infilled reinforced concrete frames in the past decades. Mortar is used as a binder in normal brick construction in order to create continuous structural form and to bind together the individual units in brickwork. In the present study, analysis has been carried out by considering the increase in height of building from five to ten storied by using finite element software ANSYS 14.5. The seismic analysis of multi-storeyed building frames with infill walls and without infill walls are conducted. 3D analysis will give more realistic values of deflection and stresses. Since this type of study is not feasible in terms of analysis time taken, 2D model was adopted for the present study. A three bay two dimensional building frame is considered with the number of stories varying from 5 storied to 10 storied. The loading applied is as per IS 1893 (Part I): 2002. Equivalent diagonal strut method is adopted for modelling infill walls. The results showed that there is considerable decrease in deflection when infills are used in RC frames. Key Words: Deflection , Equivalent diagonal strut method, lateral load, Solid brick infills, Storey drift
DESIGN OF RIGID PAVEMENT AND ITS COST-BENEFIT ANALYSIS BY USAGE OF VITRIFIED ...IAEME Publication
A country can achieve sustainable and rapid growth in all fields by improving its connectivity and transit systems. Connectivity of people to resources by improved transit mechanism results in improved living standards. Apart from other means, the major part of connectivity of any country is through road systems. Well designed and maintained pavements provide better and long lasting service. In India, all the major road systems are designed as flexible pavements only, because of their ease of construction and less time it takes to be opened to traffic operations. The major problem with flexible pavements is their design life and high maintenance costs. Also, globally reducing petrol reserves, which are used for bitumen and asphalt production are also increasing the need for alternatives. To tackle these problems, rigid pavements can be constructed. Although the cost of construction of rigid pavements is high, its long life, high load carrying capabilities and low maintenance cost will balance the initial cost aspect. Recently, many studies are being conducted on different pozzolanic admixtures which can be used as partial replacement of cement in rigid pavements, thereby reducing its cost and enhancing properties of the mix. Here, an attempt is made to reduce the construction cost of rigid pavements by incorporating Vitrified Polish Waste (VPW) as partial cement replacement in proportions of 5% for M40 grade concrete. Further, to enhance flexural properties of pavement, Recron fibre is added to optimum VPW in increments of 0.1%, then after C.C pavement is designed for two lane two way national highway and cost benefit analysis is performed.
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
Seismic evelution of rc space frame with rectangular and equivalent square co...eSAT Publishing House
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
Ultra-Thin Whitetopping in India: State-of- Practice IDES Editor
Ultra-Thin Whitetopping (UTW) is a technology to
construct 50-100mm thick cement concrete overlay on
distressed asphalt pavement as a rehabilitation technique.
There have been several UTW projects completed in India,
the first in Pune, subsequently in New Delhi, Ghaziabad,
Mumbai, and Thane. All projects have shown good to excellent
performance so far, indicating that this rehabilitation strategy
can stand up to the Indian climate and traffic conditions. The
suitability of UTW rehabilitation for a particular site is
dependent on several factors including existing asphalt
thickness, volume of truck traffic, base and subgrade support,
and pavement conditions. This paper outlines the state-of-
practice in India for construction of UTW considering mix
traffic, extreme climatic conditions, use of indigenous
materials and design aspects as per Indian Road Congress
(IRC) guidelines.
Analysis of Shear Live Load Girder Distribution Factors in Integral bridges u...IJCMESJOURNAL
This paper studies the accuracy of AASHTO Standard Specifications and AASHTO LRFD design specifications girder distribution factors (GDFs) equations and their applicability to integral abutment bridges (IABs). A three-dimensional (3D) finite element (FE) model of the Scotch Road integral abutment bridge was developed using the finite element software ABAQUS/Cae. The bridge was subjected to vehicular live loading in single and multiple lanes in the FE model(s). The FE model was calibrated using load-displacement data obtained from field testing due to static truck loading. A comparison between the GDFs obtained from the FE models to those computed using both design codes was performed to evaluate their accuracy. A limited parametric study was conducted to evaluate crucial design parameters such as bridge deck thickness, span length, and piles lengths. The results showed that AASHTO LRFD GDFs equations are more conservative compared to those of AASHTO LFD equations in all cases. However, GDFs from the FE models compared more favorably to those calculated based on both design codes for the case single lane loading.
Behaviour of 3 d rc frames with masonry infill under earthquake loads an ana...eSAT Journals
Abstract Moderate and astringent earthquakes have struck different places in the world, causing rigorous damage to reinforced concrete
structures. The bond between the structural elements and masonry in-fills of the building is habitually effected by Earthquake. The
voids between horizontal and vertical resisting elements of the building frame is filled by Masonry in-fills. An infill wall enhances
considerably the strength and rigidity of the structure. It has apperceived that frames with in-fills have more vigor and rigidity
compared to the bare frames Hence this study is about the demeanor of 3D-RC frames with and without masonry in-fills utilizing
E-TABS. parameters were studied like displacement, lateral load distribution, stiffness and overturning moment of the frames and
it is concluded that, the in-fill walls are needed to be considered while designing phase of the structures.
Keywords: Earthquake load, 3D RC Frame, Masonry In-Fill
Rehabilitation of low volume flexible pavements by white topping a case studyeSAT Publishing House
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.
Analysis of Behaviour of U-Girder Bridge DecksIDES Editor
The concept of U-shaped bridge girder is now being
increasingly adopted in urban metro rail projects and for
replacing old bridges where there is a constraint on vertical
clearance. These bridge decks are commonly designed in
practice using simplified methods that assume beam action of
the webs in the longitudinal direction and similar flexural
action of the deck slab in the transverse direction. However,
such assumptions can lead to errors. This paper attempts to
assess the extent of error in the simplified analysis, by
comparing the results with a more rigorous three-dimensional
finite element analysis (3DFEA). A typical prototype railway
bridge girder has been taken as a case study. The results of
the 3DFEA, in terms of load-deflection plots, have been
validated by field testing.
EXPERIMENTAL STUDY ON COIR FIBRE REINFORCED FLY ASH BASED GEOPOLYMER CONCRETE...IAEME Publication
Background/Objectives: By using the fly residue as option substance to bond in concrete it reduces the usage of normal Portland cement in usual concrete which results in the development of Geopolymer concrete furthermore in the lessening of CO2 levels which thusly reduces the Global Warming. Methods/Statistical analysis: This paper presents the trial examination done on the execution of coir fibre reinforced fly residue based geopolymer concrete subjected to severe ecological conditions. The mixes were considered for molarity of 10M. The basic arrangement utilized for present revise is the blend of sodium silicate and sodium hydroxide arrangement with the proportion of 1:2.5. Coir fibre with the varying percentages of 0, 0.75, 1.5, 2.25 and 3 are used as fibre reinforcement. The test specimens of 150mmx150mmx150mm cubes, 150mmx300mm cylinders, 1000mmx150mmx150mm beams are cast and cured under encompassing temperature conditions. Findings: The geopolymer solid examples are tried for their compressive quality, flexural and split tractable tests at 7days, 14days and 28days.The test grades demonstrate that the blend of fly ash and coir fibre can be used for the improvement of geopolymer concrete. Applications: It possesses superior distinctiveness such as high strength, very little drying shrinkage , low creep, durable nature, eco-friendly, fire proof ,better compressive strength etc to be used as an alternative of OPC
Determination of load transfer in reinforced concrete solid slabs by finite e...IOSR Journals
According to the ACI building code, the concrete slab can be divided into two types depending on
the ratio of the long side to the short side. Regarding the results of the ratio, the concrete slab can be divided as
one-way and two-way slabs. The main objective of this paper is to study the stress or moments distribution in
solid slab panel in its two directions and compare with ACI code assumption that the load is transferred mainly
in short direction and most of the load is transferred in one direction only if the ratio of the longer span to the
shorter span is greater than one. This will be discussed by analyzing one panel of solid slab using the computer
software SAP2000. Two types of panels will be used; the first one a panel that is supported simply on its four
sides and the second panel is supported only by four pin supports and beams. This paper shows that the gravity
load on the slab is transferred to long and short direction. This means that one-way concrete solid slab doesn't
exist and all concrete solid slabs work as a two-way concrete slab.
Heuristic Techniques for the Design of Steel-Concrete Composite Pedestrian Br...► Victor Yepes
The objective of this work was to apply heuristic optimization techniques to a steel-concrete composite pedestrian bridge, modeled like a beam on two supports. A program has been developed in Fortran programming language, capable of generating pedestrian bridges, checking them, and evaluating their cost. The following algorithms were implemented: descent local search (DLS), a hybrid simulated annealing with a mutation operator (SAMO2), and a glow-worms swarm optimization (GSO) in two variants. The first one only considers the GSO and the second combines GSO and DLS, applying the DSL heuristic to the best solutions obtained by the GSO. The results were compared according to the lowest cost. The GSO and DLS algorithms combined obtained the best results in terms of cost. Furthermore, a comparison between the CO2 emissions associated with the amount of materials obtained by every heuristic technique and the original design solution were studied. Finally, a parametric study was carried out according to the span length of the pedestrian bridge.
Efficiency of vertical drains using finite element method may 2017Dr Mazin Alhamrany
Incorporating one-dimensional bar elements with two-dimensional quadrilateral axisymmetrical elements to tackle problems of consolidation of clay with vertical drains.
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Finite element analysis of innovative solutions of precast concrete beamcolum...Franco Bontempi
Especially to precast concrete structure connections are one of the most essential parts. Connections transfer forces between precast members, so the interaction between precast units is obtained. They are generally the
weakest link in the structure. An acceptable performance of precast concrete structure depends especially on the
appropriate kind of connections choice, adequate detailing of components and design of the connections is fundamental. It is interesting to study the behavior of connecting elements and to compare different solutions of ductile connections for precast concrete structures in case of horizontal applied force and vertical imposed displacement, as well as those produced by hazards situation, like that earthquake and explosion, whereby topics of structure robustness are carried out. The case of study is an innovative dissipative system of connection between precast concrete elements, usable for buildings and bridges, the investigation of these topics is carried out by F.E.A. by program DIANA with comparison with results obtained independently with ASTER.
Effect of infill walls on the seismic performance of the multistoried buildingseSAT Journals
Abstract The most commonly used structural system in our country for almost all types of building are multi-storey reinforced concrete frames with masonry infills. Therefore it is essential to understand the seismic behaviour of these structures when subjected to lateral forces. Several research works has been done on the masonry infilled reinforced concrete frames in the past decades. Mortar is used as a binder in normal brick construction in order to create continuous structural form and to bind together the individual units in brickwork. In the present study, analysis has been carried out by considering the increase in height of building from five to ten storied by using finite element software ANSYS 14.5. The seismic analysis of multi-storeyed building frames with infill walls and without infill walls are conducted. 3D analysis will give more realistic values of deflection and stresses. Since this type of study is not feasible in terms of analysis time taken, 2D model was adopted for the present study. A three bay two dimensional building frame is considered with the number of stories varying from 5 storied to 10 storied. The loading applied is as per IS 1893 (Part I): 2002. Equivalent diagonal strut method is adopted for modelling infill walls. The results showed that there is considerable decrease in deflection when infills are used in RC frames. Key Words: Deflection , Equivalent diagonal strut method, lateral load, Solid brick infills, Storey drift
DESIGN OF RIGID PAVEMENT AND ITS COST-BENEFIT ANALYSIS BY USAGE OF VITRIFIED ...IAEME Publication
A country can achieve sustainable and rapid growth in all fields by improving its connectivity and transit systems. Connectivity of people to resources by improved transit mechanism results in improved living standards. Apart from other means, the major part of connectivity of any country is through road systems. Well designed and maintained pavements provide better and long lasting service. In India, all the major road systems are designed as flexible pavements only, because of their ease of construction and less time it takes to be opened to traffic operations. The major problem with flexible pavements is their design life and high maintenance costs. Also, globally reducing petrol reserves, which are used for bitumen and asphalt production are also increasing the need for alternatives. To tackle these problems, rigid pavements can be constructed. Although the cost of construction of rigid pavements is high, its long life, high load carrying capabilities and low maintenance cost will balance the initial cost aspect. Recently, many studies are being conducted on different pozzolanic admixtures which can be used as partial replacement of cement in rigid pavements, thereby reducing its cost and enhancing properties of the mix. Here, an attempt is made to reduce the construction cost of rigid pavements by incorporating Vitrified Polish Waste (VPW) as partial cement replacement in proportions of 5% for M40 grade concrete. Further, to enhance flexural properties of pavement, Recron fibre is added to optimum VPW in increments of 0.1%, then after C.C pavement is designed for two lane two way national highway and cost benefit analysis is performed.
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
Seismic evelution of rc space frame with rectangular and equivalent square co...eSAT Publishing House
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
Ultra-Thin Whitetopping in India: State-of- Practice IDES Editor
Ultra-Thin Whitetopping (UTW) is a technology to
construct 50-100mm thick cement concrete overlay on
distressed asphalt pavement as a rehabilitation technique.
There have been several UTW projects completed in India,
the first in Pune, subsequently in New Delhi, Ghaziabad,
Mumbai, and Thane. All projects have shown good to excellent
performance so far, indicating that this rehabilitation strategy
can stand up to the Indian climate and traffic conditions. The
suitability of UTW rehabilitation for a particular site is
dependent on several factors including existing asphalt
thickness, volume of truck traffic, base and subgrade support,
and pavement conditions. This paper outlines the state-of-
practice in India for construction of UTW considering mix
traffic, extreme climatic conditions, use of indigenous
materials and design aspects as per Indian Road Congress
(IRC) guidelines.
Analysis of Shear Live Load Girder Distribution Factors in Integral bridges u...IJCMESJOURNAL
This paper studies the accuracy of AASHTO Standard Specifications and AASHTO LRFD design specifications girder distribution factors (GDFs) equations and their applicability to integral abutment bridges (IABs). A three-dimensional (3D) finite element (FE) model of the Scotch Road integral abutment bridge was developed using the finite element software ABAQUS/Cae. The bridge was subjected to vehicular live loading in single and multiple lanes in the FE model(s). The FE model was calibrated using load-displacement data obtained from field testing due to static truck loading. A comparison between the GDFs obtained from the FE models to those computed using both design codes was performed to evaluate their accuracy. A limited parametric study was conducted to evaluate crucial design parameters such as bridge deck thickness, span length, and piles lengths. The results showed that AASHTO LRFD GDFs equations are more conservative compared to those of AASHTO LFD equations in all cases. However, GDFs from the FE models compared more favorably to those calculated based on both design codes for the case single lane loading.
Behaviour of 3 d rc frames with masonry infill under earthquake loads an ana...eSAT Journals
Abstract Moderate and astringent earthquakes have struck different places in the world, causing rigorous damage to reinforced concrete
structures. The bond between the structural elements and masonry in-fills of the building is habitually effected by Earthquake. The
voids between horizontal and vertical resisting elements of the building frame is filled by Masonry in-fills. An infill wall enhances
considerably the strength and rigidity of the structure. It has apperceived that frames with in-fills have more vigor and rigidity
compared to the bare frames Hence this study is about the demeanor of 3D-RC frames with and without masonry in-fills utilizing
E-TABS. parameters were studied like displacement, lateral load distribution, stiffness and overturning moment of the frames and
it is concluded that, the in-fill walls are needed to be considered while designing phase of the structures.
Keywords: Earthquake load, 3D RC Frame, Masonry In-Fill
Rehabilitation of low volume flexible pavements by white topping a case studyeSAT Publishing House
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.
Analysis of Behaviour of U-Girder Bridge DecksIDES Editor
The concept of U-shaped bridge girder is now being
increasingly adopted in urban metro rail projects and for
replacing old bridges where there is a constraint on vertical
clearance. These bridge decks are commonly designed in
practice using simplified methods that assume beam action of
the webs in the longitudinal direction and similar flexural
action of the deck slab in the transverse direction. However,
such assumptions can lead to errors. This paper attempts to
assess the extent of error in the simplified analysis, by
comparing the results with a more rigorous three-dimensional
finite element analysis (3DFEA). A typical prototype railway
bridge girder has been taken as a case study. The results of
the 3DFEA, in terms of load-deflection plots, have been
validated by field testing.
EXPERIMENTAL STUDY ON COIR FIBRE REINFORCED FLY ASH BASED GEOPOLYMER CONCRETE...IAEME Publication
Background/Objectives: By using the fly residue as option substance to bond in concrete it reduces the usage of normal Portland cement in usual concrete which results in the development of Geopolymer concrete furthermore in the lessening of CO2 levels which thusly reduces the Global Warming. Methods/Statistical analysis: This paper presents the trial examination done on the execution of coir fibre reinforced fly residue based geopolymer concrete subjected to severe ecological conditions. The mixes were considered for molarity of 10M. The basic arrangement utilized for present revise is the blend of sodium silicate and sodium hydroxide arrangement with the proportion of 1:2.5. Coir fibre with the varying percentages of 0, 0.75, 1.5, 2.25 and 3 are used as fibre reinforcement. The test specimens of 150mmx150mmx150mm cubes, 150mmx300mm cylinders, 1000mmx150mmx150mm beams are cast and cured under encompassing temperature conditions. Findings: The geopolymer solid examples are tried for their compressive quality, flexural and split tractable tests at 7days, 14days and 28days.The test grades demonstrate that the blend of fly ash and coir fibre can be used for the improvement of geopolymer concrete. Applications: It possesses superior distinctiveness such as high strength, very little drying shrinkage , low creep, durable nature, eco-friendly, fire proof ,better compressive strength etc to be used as an alternative of OPC
Determination of load transfer in reinforced concrete solid slabs by finite e...IOSR Journals
According to the ACI building code, the concrete slab can be divided into two types depending on
the ratio of the long side to the short side. Regarding the results of the ratio, the concrete slab can be divided as
one-way and two-way slabs. The main objective of this paper is to study the stress or moments distribution in
solid slab panel in its two directions and compare with ACI code assumption that the load is transferred mainly
in short direction and most of the load is transferred in one direction only if the ratio of the longer span to the
shorter span is greater than one. This will be discussed by analyzing one panel of solid slab using the computer
software SAP2000. Two types of panels will be used; the first one a panel that is supported simply on its four
sides and the second panel is supported only by four pin supports and beams. This paper shows that the gravity
load on the slab is transferred to long and short direction. This means that one-way concrete solid slab doesn't
exist and all concrete solid slabs work as a two-way concrete slab.
Heuristic Techniques for the Design of Steel-Concrete Composite Pedestrian Br...► Victor Yepes
The objective of this work was to apply heuristic optimization techniques to a steel-concrete composite pedestrian bridge, modeled like a beam on two supports. A program has been developed in Fortran programming language, capable of generating pedestrian bridges, checking them, and evaluating their cost. The following algorithms were implemented: descent local search (DLS), a hybrid simulated annealing with a mutation operator (SAMO2), and a glow-worms swarm optimization (GSO) in two variants. The first one only considers the GSO and the second combines GSO and DLS, applying the DSL heuristic to the best solutions obtained by the GSO. The results were compared according to the lowest cost. The GSO and DLS algorithms combined obtained the best results in terms of cost. Furthermore, a comparison between the CO2 emissions associated with the amount of materials obtained by every heuristic technique and the original design solution were studied. Finally, a parametric study was carried out according to the span length of the pedestrian bridge.
This paper introduces a two dimensional bridge deck for a cantilever bridge with a 15 m long span that has been modelled and analysed using computational modelling software (LUSAS) to obtain maximum moments and
shear forces. The significance of the problem is to determine the worst scenario case within the deck in terms of highest
bending moment and shear force, for example, the most affected parts of deck under load. The problem was tackled
with the aid of LUSAS Bridge Plus which is part of LUSAS software package. Generally, LUSAS Bridge Plus works
by analysing equations and allowing combinations of load case results.
Comparative Study of Girders for Bridge by Using SoftwareIJERA Editor
According to various research papers, it has been found that composite bridge gives the maximum strength in
comparison to other bridges and the design and analysis of various girders for steel and concrete by using
various software for composite bridge design for girder. In this project, efforts will make to carry outto check
the analysis of girder by using SAP2000 software. Hence, in this project determine three girders which can be
effective to the composite bridges.
Monte Carlo simulation for seismic analysis of a long span suspension bridgeFranco Bontempi
Sgambi L et al. Monte Carlo simulation for seismic analysis of a long span suspension bridge. Eng Struct (2014), http://
dx.doi.org/10.1016/j.engstruct.2014.08.051
The seismic analysis of long-span cable suspended bridges is undoubtedly a problem in structural analysis that involves a high number of uncertain parameters. In this work, through a probabilistic approach (Monte Carlo simulation) seismic analysis is carried out able to take into account the variability of certain factors relating to the seismic input. Displacement time histories, necessary to define seismic scenarios, are built artificially based on the response spectrum of the site. The analysis is carried out using a 3D numerical model built using one-dimensional finite elements using ADINA software code. This model has been developed in conjunction with a purpose-built program in FORTRAN language to conduct the Monte Carlo simulations. The results expressed in terms of displacements and stresses are described by their average value and their variance.
Monte Carlo simulation for seismic analysis of a long span suspension bridgeStroNGER2012
Sgambi L et al. Monte Carlo simulation for seismic analysis of a long span suspension bridge. Eng Struct (2014), http://
dx.doi.org/10.1016/j.engstruct.2014.08.051
The seismic analysis of long-span cable suspended bridges is undoubtedly a problem in structural analysis that involves a high number of uncertain parameters. In this work, through a probabilistic approach (Monte Carlo simulation) seismic analysis is carried out able to take into account the variability of certain factors relating to the seismic input. Displacement time histories, necessary to define seismic scenarios, are built artificially based on the response spectrum of the site. The analysis is carried out using a 3D numerical model built using one-dimensional finite elements using ADINA software code. This model has been developed in conjunction with a purpose-built program in FORTRAN language to conduct the Monte Carlo simulations. The results expressed in terms of displacements and stresses are described by their average value and their variance.
Embodied Energy Optimization of Prestressed Concrete Slab Bridge Decks► Victor Yepes
This paper presents one approach to the analysis and design of post-tensioned cast-in-place concrete slab bridge decks. A Simulated Annealing algorithm is applied to two objective functions: (i) the economic cost; and (ii) the embodied energy at different stages of production materials, transport, and construction. The problem involved 33 discrete design variables: five geometrical ones dealing with the thickness of the slab, the inner and exterior web width, and two flange thicknesses; concrete type; prestressing cables, and 26 variables for the reinforcement set-up. The comparison of the results obtained shows two different optimum families, which indicates that the traditional criteria of economic optimization leads to inefficient designs considering the embodied energy. The results indicate that the objectives are not competing functions, and that optimum energy designs are close to the optimum cost designs. The analysis also showed that the savings of each kW h of energy consumed carries an extra cost of 0.49€. The best cost solution presents 5.3% more embodied energy. The best energy solution is 9.7% more expensive than that of minor cost. In addition, the results have showed that the best cost solutions are not the best energy solutions.
As catastrophic bridge collapse accidents not only cause significant loss of property, but also have a severe social impact. Therefore, the structural health monitoring of bridges for damage detection by vibration analysis gets more attention. Reinforced concrete bridges are the most common and extended structures present in the worldwide. These structures are often characterized by Piers, Abutments, deck slabs. This paper looks on the work of modelling and analysis of bridge in STAAD.Pro software, and the specific bridge model is taken of a particular span. It is subjected to vary Young’s modulus (E) in the mid span of bridge deck slab to induce damage in order to obtain maximum bending moment, as the structural strength reduces. From the analysis Mu/bd2 values from SP 16 code is used to identify the damage on the bridge deck slab, then natural frequency of the bridge, mode shapes, variation of the deflection and node displacements of bridge deck slab under the action of static and dynamic load at different aspect ratios with original design parameters and at failure is carried out in this project.
A Review Paper on Analysis of T Beam Deck Type and T Beam Pre Stressed Deck B...ijtsrd
A Bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. K is the portion of a bridge that acts as the roadway in the support of vehicular or pedestrian traffic. While deck parts like trusses, girders, rails, arches, posts and cantilevers assume a number of forms and types, there are relatively few bridge deck types given the utilitarian nature of the component. Rudresh Meena | Prof. Afzal Khan "A Review Paper on Analysis of T Beam Deck Type and T Beam Pre-Stressed Deck Bridge" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-7 | Issue-2 , April 2023, URL: https://www.ijtsrd.com.com/papers/ijtsrd57385.pdf Paper URL: https://www.ijtsrd.com.com/engineering/civil-engineering/57385/a-review-paper-on-analysis-of-t-beam-deck-type-and-t-beam-prestressed-deck-bridge/rudresh-meena
Optimum Dimensions of Suspension Bridges Considering Natural PeriodIOSR Journals
Abstract: Suspension bridge is an efficient structural system particularly for large spans. Many difficulties
related to design and construction feasibility arises due to its long central span. There are many suspension
bridges around the world and dynamic behavior has been found to be the primary concern for those bridges.
Natural period of a suspension bridge mainly dependent on the span and other structural dimensions related to
the stiffness. In the present study, the effects of structural parameters like deck depth and tower height on
natural period of suspension bridges having different central spans are conducted. Natural periods are
analyzed by modal analysis for central span lengths ranges from 600m to 1400m. The modal analysis is
performed by finite element software package SAP2000. For each central span, tower heights and deck depth
are varied and the consequences of these variations on the natural periods of various types of vibration modes
are investigated and dominant mode for each span is recognized. Obtained values from the analysis were
utilized to plot three dimensional surfaces representing correlation among natural period, deck depth, tower
height, and span, using MATLAB functions. A relationship among tentative optimum deck depth, optimum tower
height and central span of suspension bridge is developed for obtaining minimum natural period. This
relationship can be used to obtain the tentative optimum dimensions of a suspension bridge with central span
between 600m to 1400m.
Keywords: suspension bridge, natural period, optimum dimensions, modal analysis.
Effect of configuration on lateral displacement and cost of the structure for...eSAT Journals
Abstract
The choice of a cost effective lateral-force-resisting system for high-rise structures is challenging. There is no streamlined methodology to quantitatively compare the cost-effectiveness of each system beyond the more qualitative perception based evaluation of advantages or disadvantages. Developers currently base their decisions on architectural layout and structural integrity. Cost considerations are often primarily based on experience.
This decision making process has three primary shortfalls.
1) It may not incorporate factors which greatly affect the economy of a particular framing system.
2) It may not allow engineers to carryout designs at the least cost.
3) Comparison of framing systems may not address the specific building types.
This investigation proposes a prototype cost-effective model for selecting either a skeleton framing system or skeleton frame with bracing system for steel structural frames. A model for selecting cost-effective skeleton framing system or skeleton frame with bracing system will be a valuable tool for all decision makers. Engineers, in particular, will be able to select optimal steel framing faster, thus reducing design time and iterations. Furthermore, selection of economic framing system will also result in direct cost savings for steel structural frames.
The study involves the design and cost estimation of steel frames representing skeleton framing system and skeleton frame with bracingsystem. The cost effectiveness of the framing systems are compared based on lateral displacement requirements and cost.The preferred framing system should meet lateral displacement requirements and is lower in cost. The results of this pilot study showed that the Skelton framing system with bracing is the cost-effective choice for 30storeys steel space frames at wind speeds of 55m/sec, 50m/sec and 47m/sec.
Keywords: Bracings, SFS (Skeleton framing system), SFWB (Skeleton frame with bracing system) etc…
Optimization of Design Parameters for Crane Hook Using Finite Element AnalysisIJRTEMJOURNAL
The Crane hooks are very at risk segments that are regularly utilized for mechanical purposes.
In this way such segments in an industry must be produced and composed in an approach to convey most extreme
execution without failure. Failure of a crane hook essentially relies upon three central point i.e. measurement,
material, overload. The undertaking is worried towards expanding the safe load by fluctuating the cross-sectional
measurements of the four distinct segments and diverse materials. The chose areas are square, circle, and
trapezoidal. The territory stays consistent while changing the measurements of the four unique segments. The
crane hook is demonstrated utilizing catia programming. The pressure and life investigation is finished utilizing
ANSYS 18.1 workbench. The ordinary worry along add up to misshaping, stress and life’s according to the
materials considered. It is discovered that trapezoidal cross segment yields most extreme load of 4000 KG to 5000
KG for steady cross segment zone among four cross segment.
Reinforced concrete (RC) has become one of the most important building materials and is widely used in
many types of engineering structures. For the efficient use of RCC it is necessary to know the properties and the
behavior of RCC elements under various constrains. Within the framework of developing advanced design and
analysis methods for modern structures the need for experimental research continues
Reinforced concrete (RC) has become one of the most important building materials and is widely used in
many types of engineering structures. For the efficient use of RCC it is necessary to know the properties and the
behavior of RCC elements under various constrains. Within the framework of developing advanced design and
analysis methods for modern structures the need for experimental research continues
ANALYSIS AND COMPARATIVE STUDY OF COMPOSITE BRIDGE GIRDERSIAEME Publication
The composite bridge gives the maximum strength in comparison to other bridges. The design and analysis of various girders for steel and concrete by using various software, in that paper for composite bridge calculate the bending moment for T girder and finding which is more effective. The efforts will make to carry out to check the analysis of bridge by using SAP 2000 software. To determine the static analysis of T girder by using manual method as well as software. The results obtained from the software in structural analysis are compare the results obtained from manual calculations.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
2. Parametric study of concrete box-girder footbridges 68
topics arose, such as, the structural behavior at
different construction stages [3,8], the durability
conditions and their effect on the strength
conditions [9,10], deflections during construction
[11], long-term behavior [12], life-cycle assessment
[13,14] and multi-criteria decision making methods
applied to the sustainable bridge design [15].
Some authors have published recommendations
for the geometry and material of prestressed
concrete bridge design [2,16-18]. These guides are
useful in the first stage in the design process. Once
the geometrical layout is a priori defined, the
stresses and displacement are compared with the
allowable values, according to the code
specifications [19,20]. Should the initial design
dimensions or material grades be insufficient or
excessive, the structure is redefined on a trial-and-
error basis. The final design does not guarantee to
be optimal. For that reason, structural optimization
methods are clear alternatives to designs based on
experience. However, finding the optimal design is
a difficult and challenging task since it requires
deciding on many variables such that the design
goals are fulfilled while many constraints are
satisfied. In fact, these methods are seldom adopted
by practicing engineers, who prefer intuition-based
trial-and-error methods to optimization algorithms.
A review of heuristic algorithms applied to
structural optimization is presented in the study of
Hare et al. [21]. For the complex and realistic non-
linear structural optimization problems that are
investigated in this study, these algorithms appear
to be the only reliable approach.
Srinivas and Ramanjaneyulu [22] minimized
the cost of a T girder bridge deck using artificial
neural networks and genetic algorithms. Hernández
et al. [23] optimized the design of prestressed
concrete beams. Martínez-Martín et al. [24]
proposed a variant of ant colony optimization to
optimize tall bridge piers. Martí-Vargas et al. [25]
predicted the transfer length of prestressing strands
with neural networks. Rana et al. [26] presented an
evolutionary operation, based on a global
optimization algorithm for the minimum cost
design of a two-span, continuous, prestressed
concrete I-girder bridge structure. A hybrid
simulated annealing algorithm [27] and a memetic
algorithm with variable-depth neighborhood search
[28] were applied to find the most economical
solution for precast-prestressed concrete U-beam
road bridges. A glowworm swarm algorithm was
used to optimize concrete I-beams [29]. However,
studies on the optimum box girder design are
comparatively scarce [30-33]. Hassanain and Loov
[34] present a review of cost optimization of
concrete bridge infrastructure.
In addition to the above, the use of other
materials, like high-strength concrete, can alter the
design criteria [35,36]. The use of high-strength
concrete reduces self-weight and, therefore, the
amount of concrete and steel required. To this end,
this study employs the SAMO2 heuristic
optimization technique to find the best economic
designs for a box-girder pedestrian bridge made
with different concrete grades for a three-span deck
in which the main span ranges from 30 to 60 m. For
this purpose, a program encompasses modules for
structural analysis, limit states verification and cost
evaluation. We demonstrate not only the
applicability of the algorithm to the structure, but
also we provide practicing engineers with
guidelines for the efficient design.
2. Optimum bridge design problem
This study minimizes the cost of a continuous beam
deck with a box-girder cross section of post-
tensioned concrete. A candidate design is defined
by design variables (x1, x2... xn). The problem
involves an objective function F of Eq. (1), subject
to the constraints represented by Eq. (2).
F(𝑥𝑥1,𝑥𝑥2,.....𝑥𝑥𝑛𝑛) (1)
𝐺𝐺𝑗𝑗(𝑥𝑥1,𝑥𝑥2,.....𝑥𝑥𝑛𝑛)≤0 (2)
The objective function evaluates the cost for the
total number of construction units (r), considering
material and placement costs listed in Eq. (3).
𝐶𝐶 = ∑ 𝑝𝑝𝑖𝑖𝑖𝑖=1,𝑟𝑟 × 𝑚𝑚𝑖𝑖�𝑥𝑥1, 𝑥𝑥2, … . , 𝑥𝑥𝑛𝑛� (3)
Unit prices (pi), shown in Table 1, were
obtained from the BEDEC ITEC database
(Catalonia Institute of Construction Technology,
3. 69 Yepes et al.
Table 1. Basic prices
Unit measurements Cost (€)
m3
of scaffolding 10.02
m2
of formwork 33.81
m3
of lighting 104.57
kg of steel (B-500-S) 1.16
kg of post-tensioned steel (Y1860-S7) 3.40
m3
of concrete HP-35 104.57
m3
of concrete HP-40 109.33
m3
of concrete HP-45 114.10
m3
of concrete HP-50 118.87
m3
of concrete HP-55 123.64
2015). Concrete unit prices were determined for
each compressive strength grade according to the
mix design, including the cost of raw materials
extraction, manufacture and transportation. The
measurements (mi) concerning the construction
units depend on the design variables.
This study describes the cost minimization of a
pedestrian deck bridge with three spans and a low
height. The three spans into which the deck length
is split follow the relation that the external span is
80% of the central (Fig. 1). The pedestrian bridge is
3.5 m wide. This problem includes 33 discrete
design variables that define the geometry, the
concrete, the reinforcing steel bars and the post-
tensioned steel. The parameters define the overall
geometry, the materials, the loads acting on the
structure, the exposure class, and the Spanish codes
for structural concrete and bridge design loads
followed by this study [19,20]. To this end, a
program analyzes and evaluates the serviceability
and ultimate limit states (SLS and ULS) and the
geometrical and constructability requirements. This
modulus verifies the demands of the safety, as well
as those relating to the aptitude for service
requirement. The structure was modelled by a linear
element with 30 bars, 31 sections and 93 degrees of
freedom. Transverse analysis was carried out using
a frame model. Besides, the minimum amount of
reinforcement for the stress requirements and the
geometrical conditions are also examined. The
readers are encouraged to refer to our previous
work [30] for detailed description of the design
Fig. 1. Three span post-tensioned concrete box-girder
bridge
variables, the parameters, and the structural
analysis and constraints.
3. SAMO2 optimization algorithm
The heuristic method used for this study is a hybrid
SA algorithm with a mutation operator (SAMO).
SAMO, proposed by Martí et al. [27], takes both of
the benefits of good convergence in simulated
annealing and enhancing diversity of genetic
strategy. SAMO takes both of the advantages of
good convergence in simulated annealing and
enhancing diversity of genetic strategy. Here, we
propose an extended version of SAMO, called
SAMO2. SAMO2 accepts worse solutions when
the increment is lower than a value, which depends
on the temperature and a stochastic variable.
Therefore, this probabilistic jumping property
facilitates global optimum searching. Eq. (4) gives
the transition rule of this method.
𝑝𝑝𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆2 =
1
1+𝑒𝑒
𝛥𝛥𝛥𝛥
𝑇𝑇
(4)
The calibrated method involves random
variation of up to 50% of the variables, the initial
temperature by Medina’s method, Markov chains of
5000 iterations, a cooling coefficient of 0.80 and a
stop criterion of three Markov chains without
improvement. The algorithm was coded in
MATLAB with an INTEL® CoreTM i7-3820 CPU
processor and 3.6 GHz. Computer runs were
performed nine times, according to the extreme
value theory methodology used by Carbonell et al.
[37], to obtain minimum, mean and standard
deviations of the random results. The difference
between the minimum cost obtained after nine runs
and the extreme value estimated was €509.53, a
difference of just 0.34% compared to the theoretical
minimum value. From the point of view of the
4. Parametric study of concrete box-girder footbridges 70
structural engineer, this indicates that the difference
is small enough to make the solution provided by
the proposed SAMO2 acceptable.
4. Best results for the span-length parametric
study
This section presents the best solutions for five
three-span bridges with the main span ranging from
30 to 60 m. Table 2 gives the best geometrical
characteristics obtained after nine computer runs
for each case. Table 3 summarizes the mean values
to detail the information. The depth and the number
of strands depended on the span length. The mean
values for the depth varied between 1/34 and 1/39
in relation to the main span and the ratio Ns/L1
ranged from 0.93 to 1.70.
The width of the bottom slab tended to the
minimum (1.4 m) to minimize the weight.
However, the geometrical restrictions conditioned
by the thickness of the webs and the haunches
forced this width to be increased. Regarding the
width of web inclination (d), there is no good
correlation between this variable and the
minimization of the cost for each span length. The
vertical web reduces the amount of concrete and,
therefore, the total cost. Nevertheless, the web
inclination reduces the cantilever length and the
width of the bottom slab. Consequently, the
longitudinal shear is decreased and there are less
depth requirements. Therefore, this variable can be
adjusted for esthetic reasons without major
economic consequences.
The thickness of every slab, except the webs,
tended to adopt the minimum value proposed by the
optimization program (150 mm). It is only
advisable to increase the thickness for geometrical
reasons, for instance, when the distance from the
reinforcing bars is a determining factor. The web
thickness took values between 400 and 460 mm.
This value enables strands to fit in this thickness
and guarantee the structural and constructability
requirements. Comparing these results with some
recommendations, it is worth noting that Ministerio
de Fomento [17] suggested slab thickness greater
than 200 mm for road bridges and web thickness of
more than 300 mm or 6 cm/m total width. Schlaich
and Scheff [2] proposed deck and bottom slabs
greater than 200 mm and 150 mm, respectively.
Regarding webs, the thickness suggested should not
be less than 300 or 200+2*Ød, where Ød is the duct
diameter. Note that loads for pedestrian bridges are
smaller and therefore, the thickness was limited in
this study to 150 mm.
The concrete type for the best solutions varied
between 35 and 55 MPa, independent of the span
length. However, analyzing the mean values, a
concrete strength increment with the span length
was highlighted.
Table 2. Best geometrical variables for 30-60 m span
L1 (m) L2 (m) h (m) b (m) d (m) es (m) ev (m) ei (m) ea (m) t (m) fck (MPa) LPI Ns
60 48 1.65 1.50 0.00 0.15 0.15 0.15 0.45 0.30 45 0.05 100
55 44 1.50 1.60 0.00 0.15 0.15 0.18 0.43 0.28 50 0.10 76
50 40 1.25 1.45 0.28 0.15 0.15 0.15 0.43 0.28 55 0.15 68
40 32 1.10 1.45 0.00 0.15 0.15 0.15 0.45 0.15 40 0.20 44
30 24 0.90 1.40 0.00 0.15 0.15 0.18 0.40 0.18 35 0.20 26
Table 3. Mean geometrical variables for 30-60 m span
L1 (m) L2 (m) h (m) b (m) d (m) es (m) ev (m) ei (m) ea (m) t (m) fck (MPa) LPI Ns
60 48 1.68 1.55 0.04 0.16 0.16 0.19 0.46 0.29 54 0.09 102
55 44 1.42 1.52 0.11 0.15 0.15 0.16 0.45 0.30 54 0.12 83
50 40 1.28 1.43 0.21 0.15 0.15 0.16 0.43 0.28 52 0.13 70
40 32 1.10 1.48 0.03 0.15 0.15 0.16 0.45 0.16 42 0.20 46
30 24 0.89 1.54 0.24 0.15 0.15 0.16 0.40 0.16 38 0.19 28
5. 71 Yepes et al.
The number and dimensions of the ducts
conditioned the haunch. The 30-m case and 40-m
case had one duct per web. Therefore, the mean
limitation was the thickness of the bottom slab.
However, other cases presented two ducts per web;
this led to an increase in the haunch to provide space
for ducts on the high and low points.
With regard to the point of inflection LPI, this
was placed at 0.2 times the span length from the pier
for the 30-m case and 40-m case. Nevertheless, as
the span length increased, this distance was
reduced. The results suggest that for longer spans
the inflection point is nearer to the pier to intensify
the prestressing steel effect in the piers.
Tables 4 and 5 summarize the best and mean
measurements to be taken into account for the
footbridge design. The mean measurements
presented better correlation with the span length
than the best measurements. Increasing the main
span length by one meter resulted in an increment
of 6.38 euros per square meter of the deck. Fig. 2
shows the relationship between the cost per square
meter of deck (C) and the main span length
(C=6.3808L1+33.296 with a regression coefficient
R2
=0.9258).
The amount of concrete and the post-tensioned
steel had a direct relation to the span length, since
these measurements depended on the depth and the
number of strands, and these variables in turn, were
intimately related to the span length. Fig. 3 shows
the correlation between the amount of steel and the
volume of concrete per square meter of the deck and
the main span length.
Fig. 2. Mean cost per m2
of deck according to the main
span length
Fig. 3. Mean amount of steel and volume of concrete per
m2 of deck according to the main span length
Table 4. Best measurements for the 30-60 m span solutions
L1
(m)
Cost (m) Cost
(€/m2
)
Concrete
(m3
/m2
)
Post-tensioned steel
(kg/m2
)
Longitudinal
reinforcement (kg/m2
)
Transverse
reinforcement (kg/m2
)
60 215393.49 391.48 0.62 31.49 23.72 45.15
55 179063.66 354.79 0.57 23.93 18.49 43.83
50 151043.99 328.93 0.50 21.41 18.38 42.73
40 100368.53 272.59 0.44 13.85 18.26 34.88
30 65230.57 235.32 0.39 8.19 19.16 29.49
Table 5. Mean measurements for the 30-60 m span solutions
L1
(m)
Cost (m) Cost
(€/m2
)
Concrete
(m3
/m2
)
Post-tensioned steel
(kg/m2
)
Longitudinal
reinforcement (kg/m2
)
Transverse
reinforcement (kg/m2
)
60 245763.61 446.68 0.66 32.19 33.65 68.84
55 184496.87 365.56 0.56 26.03 20.58 48.29
50 153146.55 333.51 0.51 22.11 20.88 42.91
40 103560.62 281.26 0.44 14.34 20.37 37.34
30 66237.03 238.95 0.39 8.82 16.10 32.04
6. Parametric study of concrete box-girder footbridges 72
The amount of post-tensioned steel per square
meter of the deck is represented by a good linear
function (P=0.7633L1-15.176 with a regression
coefficient R2
=0.9824). The volume of concrete per
square meter of deck also has a good correlation
with the span length (CO=0.0085L1+0.1131 with a
regression coefficient R2
=0.9258). One meter of
main span length involved a further 0.0085 m3
of
concrete per square meter of the deck and 0.76 kg
more of post-tensioned steel per square meter of the
deck. Longitudinal reinforcement presented less
depending on span length, since post-tensioned
steel was the biggest factor contributing to
longitudinal strength. Therefore, the proportion of
the variance of the reinforcing steel that is
predictable from the deck length is lower. A linear
relation may be used to describe the general trend
for the longitudinal reinforcing steel per square
meter of the deck (LR=0.4284L1+2.1768 with a
regression coefficient R2=0.6049) and the
transverse reinforcing steel per square meter of the
deck (TR=1.0413L1-3.0545 with a regression
coefficient R2=0.78). Comparing the mean and the
best measurements (Tables 4-5), it is worth noting
that the best values had, on average, 2% more
longitudinal reinforcement, 4% less post-tensioned
steel and 8% less transverse reinforcement.
5. Conclusion
This study has evaluated the optimum design of a
three-span deck post-tensioned concrete box-girder
pedestrian deck with a main span ranging from 30
to 60 m. The SAMO2 algorithm, which combines
SA with a mutation operator, found the economic
solutions. The findings in this study addresses that
the depth and the number of strands for the
optimum design depend on the span length, with a
relation that varies between 1/34 and 1/39 for the
depth and between 0.93 and 1.70 for the strands.
Conversely, the slab thickness is not related to the
span length. The web thickness ranges between 400
mm and 460 mm and the slab thickness is about 150
mm. The amount of steel and volume of concrete
per square meter of deck shows a good correlation
with the main span length. By increasing the main
span length by one meter, the total cost per square
meter of the deck increases by 6.38 euros on
average. Considering that the goal is addressing
practitioners’ practical needs, this parametric study
provides design criteria to guide designers as to the
characteristics of optimum box-girder pedestrian
deck bridges. Besides, the algorithm is quite
flexible to further structural designs instead of
traditional try-and-error methods.
Acknowledgments
This research was financially supported by the
Spanish Ministry of Economy and Competitiveness
along with FEDER funding (Project BIA2014-
56574-R and Project BIA2017-85098-R).
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