This document provides information on designing and detailing steel reinforcement in combined footings. It begins by defining a combined footing as a single spread footing that supports two or more columns in a straight line. It then discusses types of combined footings and provides steps for their design including proportioning the footing size, calculating shear forces and bending moments, and designing the longitudinal and transverse reinforcement. The document concludes by providing an example problem demonstrating how to design a combined footing with a central beam.
This document provides information on the structural design of a simply supported reinforced concrete beam. It includes:
- A list of students enrolled in an elementary structural design course.
- Equations and diagrams showing the forces and stresses in a reinforced concrete beam with a singly reinforced bottom section.
- Limits on the maximum depth of the neutral axis according to the grade of steel.
- Examples of analyzing the stresses and determining steel reinforcement for a given beam cross-section.
- A design example calculating the dimensions and steel reinforcement for a rectangular beam with a factored uniform load.
The document discusses the design of staircases. It begins by defining key components of staircases like treads, risers, stringers, etc. It then describes different types of staircases such as straight, doglegged, and spiral. The document outlines considerations for designing staircases like dimensions, loads, and structural behavior. It provides steps for geometric design, load calculations, structural analysis, reinforcement design, and detailing of staircases. Numerical examples are also included to illustrate the design process.
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,
Bearing capacity of shallow foundations by abhishek sharma ABHISHEK SHARMA
elements you should know about bearing capacity of shallow foundations are included in it. various indian standards are also used. Bearing capacity theories by various researchers are also included. numericals from GATE CE and ESE CE are also included.
This presentation summarizes the key aspects of one-way slab design. It defines one-way slabs as having an aspect ratio of 2:1 or greater, with bending primarily along the long axis. The presentation discusses the types of one-way slabs including solid, hollow, and ribbed. It also outlines the design considerations for one-way slabs according to the ACI code, including minimum thickness, reinforcement ratios, and bar spacing. An example problem demonstrates how to design a one-way slab for a given set of loading and dimensional conditions.
The document discusses different methods of designing concrete structures, focusing on the limit state method. It describes the limit state method's goal of achieving an acceptable probability that a structure will not become unsuitable for its intended use during its lifetime. The document then discusses stress-strain curves for concrete and steel. It covers stress block parameters and equations for calculating the depth of the neutral axis and moment of resistance for singly reinforced concrete beams. The document concludes by providing examples of analyzing an existing beam section and designing a new beam section.
This document provides information on the structural design of a simply supported reinforced concrete beam. It includes:
- A list of students enrolled in an elementary structural design course.
- Equations and diagrams showing the forces and stresses in a reinforced concrete beam with a singly reinforced bottom section.
- Limits on the maximum depth of the neutral axis according to the grade of steel.
- Examples of analyzing the stresses and determining steel reinforcement for a given beam cross-section.
- A design example calculating the dimensions and steel reinforcement for a rectangular beam with a factored uniform load.
The document discusses the design of staircases. It begins by defining key components of staircases like treads, risers, stringers, etc. It then describes different types of staircases such as straight, doglegged, and spiral. The document outlines considerations for designing staircases like dimensions, loads, and structural behavior. It provides steps for geometric design, load calculations, structural analysis, reinforcement design, and detailing of staircases. Numerical examples are also included to illustrate the design process.
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,
Bearing capacity of shallow foundations by abhishek sharma ABHISHEK SHARMA
elements you should know about bearing capacity of shallow foundations are included in it. various indian standards are also used. Bearing capacity theories by various researchers are also included. numericals from GATE CE and ESE CE are also included.
This presentation summarizes the key aspects of one-way slab design. It defines one-way slabs as having an aspect ratio of 2:1 or greater, with bending primarily along the long axis. The presentation discusses the types of one-way slabs including solid, hollow, and ribbed. It also outlines the design considerations for one-way slabs according to the ACI code, including minimum thickness, reinforcement ratios, and bar spacing. An example problem demonstrates how to design a one-way slab for a given set of loading and dimensional conditions.
The document discusses different methods of designing concrete structures, focusing on the limit state method. It describes the limit state method's goal of achieving an acceptable probability that a structure will not become unsuitable for its intended use during its lifetime. The document then discusses stress-strain curves for concrete and steel. It covers stress block parameters and equations for calculating the depth of the neutral axis and moment of resistance for singly reinforced concrete beams. The document concludes by providing examples of analyzing an existing beam section and designing a new beam section.
This document provides 10 examples of problems related to bearing capacity of foundations. The examples calculate bearing capacity using Terzaghi's analysis for different soil and foundation conditions, including cohesionless and cohesive soils, square and strip footings, and considering the water table depth. One example compares results to field plate load tests. The solutions show calculations for determining soil shear strength parameters, factor of safety, and safe bearing capacity.
This document discusses pile foundations. It begins by listing the topics that will be covered, including types of piles, pile spacing, pile caps, load testing, and failures. It then defines a pile foundation as using slender structural members like steel, concrete or timber that are installed in the ground to transfer structural loads to deeper, stronger soil layers. The document goes on to classify piles based on their function, material, and installation method. It describes common pile types such as precast concrete, driven steel, and cast-in-place piles. The document provides details on pile uses, selection factors, and installation procedures.
Combine piled raft foundation (cprf)_Er.Karan ChauhanEr.Karan Chauhan
Combine Piled Raft Foundation(CPRF) is an emerging type of new foundation techniques in High rise buildings and skyscraper which raft as a shallow foundation and pile as deep foundation works sharing the total load and reduce settlement and bending moment. the modern approach of design philosophy is included in post graduation level with soil structure interaction of CPRF and this will use to understand the basic concept regarding it.
This document provides guidance on the design of lacing and battens for built-up compression members. It discusses the key design considerations and calculations for both single and double lacing systems, including the angle of inclination, slenderness ratio, effective lacing length, bar width and thickness. Similar guidelines are given for battens, covering spacing, thickness, effective depth, transverse shear and overlap. The document also includes an example problem on designing a slab foundation for a column with given load and material properties.
1) Two-way slabs are slabs that require reinforcement in two directions because bending occurs in both the longitudinal and transverse directions when the ratio of longest span to shortest span is less than 2.
2) The document discusses various types of two-way slabs and design methods, focusing on the direct design method (DDM).
3) Using the DDM, the total factored load is first calculated, then the total factored moment is distributed to positive and negative moments. The moments are further distributed to column and middle strips using factors that consider the slab and beam properties.
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.
The document discusses retaining walls and includes:
- Definitions of retaining walls and their parts
- Common types of retaining walls including gravity, semi-gravity, cantilever, counterfort and bulkhead walls
- Earth pressures like active, passive and at rest pressures
- Design principles for stability against sliding, overturning and bearing capacity
- Drainage considerations for retaining walls
- Theories for analyzing earth pressures like Rankine and Coulomb's theories
- Sample design calculations and problems for checking stability of retaining walls
The document discusses the design of a combined footing to support two columns. It first defines what a combined footing is and why it is used. It then describes the types of combined footings and the forces acting on it. The document provides the design steps for a rectangular combined footing, which include determining dimensions, reinforcement requirements, and design checks. As an example, it shows the detailed design of a rectangular combined footing supporting two columns with loads of 450kN and 650kN respectively. The design includes calculating dimensions, reinforcement, development lengths, and design checks.
This document provides information on doubly reinforced concrete beams. It introduces the concept of doubly reinforced beams, which have reinforcement in both the tension and compression zones. This allows for an increased moment of resistance compared to singly reinforced beams. The key advantages of doubly reinforced beams are that they can be used when the applied moment exceeds the capacity of a singly reinforced beam, when beam depth cannot be increased, or when reversal of stresses may occur. The document includes stress diagrams, design concepts, and differences between singly and doubly reinforced beams.
Piles are deep foundations used to transfer structural loads through weak or wet soils to stronger soils below. Piles can be classified based on function (end bearing, friction, tension), material (concrete, timber, steel), or installation method (driven, cast-in-place). Key factors in pile design include soil properties, load types, and groundwater conditions. The ultimate load capacity of a pile considers end bearing and side friction, while the allowable load uses a factor of safety. Dynamic testing and soil parameters can be used to estimate pile capacities.
Question and Answers on Terzaghi’s Bearing Capacity Theory (usefulsearch.org)...Make Mannan
This document contains solved examples of questions on bearing capacity from previous year question papers. It includes 6 questions calculating the ultimate bearing capacity, safe bearing capacity, and size of footing for given soil properties and loading conditions using Terzaghi and general shear failure theories. The properties provided are unit weight, cohesion, friction angle, and bearing capacity factors. Depths, widths, loads, and factors of safety are also given. The step-by-step workings and solutions are shown for each question.
This document discusses the design of beams. It defines different types of beams like floor beams, girders, lintels, purlins, and rafters. It describes how beams are classified based on their support conditions as simply supported, cantilever, fixed, or continuous beams. Commonly used beam sections include universal beams, compound beams, and composite beams. The document also covers plastic analysis of beams, classification of beam sections, and failure modes of beams.
The document provides details on the design procedure for beams. It discusses estimating loads, analyzing beams to determine shear forces and bending moments, and designing beams. The design process involves selecting the beam size and shape, calculating the effective span, determining critical moments and shears, selecting reinforcement, and checking requirements such as shear capacity, deflection limits, and development lengths. An example problem demonstrates designing a singly reinforced concrete beam with a span of 5 meters to support a working live load of 25 kN/m.
Tension members are structural elements subjected to direct tensile loads. Their strength depends on factors like length of connection, size and spacing of fasteners, cross-sectional area, fabrication type, connection eccentricity, and shear lag. Failure can occur through gross section yielding, net section rupture, or block shear. Design involves selecting a member with sufficient gross area to resist factored loads in yielding, then checking strength considering net section rupture and block shear failure modes.
The document discusses different methods of designing reinforced concrete elements:
1. Modular ratio (working stress) method, which assumes elastic behavior and uses factors of safety. It was the first accepted method but has limitations.
2. Load factor method, which avoids modular ratio and uses load factors to account for ultimate loads. However, it does not consider serviceability.
3. Limit state method, adopted in modern codes, which considers both ultimate and serviceability limit states using partial safety factors applied to loads and material strengths. It provides a comprehensive solution for safety and serviceability.
This document describes cantilever retaining walls. It defines a retaining wall as a structure that maintains ground surfaces at different elevations on either side. Cantilever retaining walls consist of a stem supported by a base and resist lateral forces through bending. The document discusses the types of forces acting on retaining walls, methods for calculating lateral earth pressures, and design considerations for stability, soil pressure distribution, and reinforcement in the stem, toe slab, and heel slab.
The document describes the design of a stepped footing to support a column with an unfactored load of 800 kN. A square footing with dimensions of 2.1m x 2.1m is designed with two 300mm steps. Reinforcement of #12 bars at 150mm c/c is provided. Checks are performed for bending moment, one-way shear, two-way shear, and development length which all meet code requirements. Therefore, the stepped footing design is adequate to support the given column load.
Retaining walls are used at the Shraddha Vivanta Residency construction site in Mumbai for two main purposes. Cantilever retaining walls around 3.5 meters deep allow for a basement and four floors of stacked parking underneath the residential building. Additional retaining walls surround underground water tanks for suction and firefighting. The walls are located along the building perimeter and around the tank areas. Proper waterproofing of the retaining walls is important given their underground locations.
The document discusses the reinforcement requirements and design process for axially loaded columns. It provides guidelines on the minimum longitudinal and transverse reinforcement, including the pitch and diameter of lateral ties. Examples are given to calculate the ultimate load capacity of rectangular and circular columns based on the grade of concrete and steel. Design assumptions and checks for minimum eccentricity are also outlined.
This document provides information on designing and detailing combined footings with steel reinforcement. It begins with defining what a combined footing is and the types of combined footings. It then outlines the design steps which include proportioning the footing size, calculating shear forces and bending moments, designing the longitudinal and transverse reinforcement, and preparing bar bending schedules. An example is provided to demonstrate the full design of a combined footing with a central beam joining two columns. The summary includes designing the slab and beam sections, checking development length and shear capacity, and determining the required steel reinforcement.
- The document discusses the design of a combined footing to support two columns carrying loads of 700 kN and 1000 kN respectively.
- A trapezoidal combined footing of size 7.2m x 2m is designed to support the loads and transmit them uniformly to the soil.
- Longitudinal and transverse reinforcement is designed for the footing and a central beam is included to join the two columns. Detailed design calculations and drawings of the footing and beam are presented.
This document provides 10 examples of problems related to bearing capacity of foundations. The examples calculate bearing capacity using Terzaghi's analysis for different soil and foundation conditions, including cohesionless and cohesive soils, square and strip footings, and considering the water table depth. One example compares results to field plate load tests. The solutions show calculations for determining soil shear strength parameters, factor of safety, and safe bearing capacity.
This document discusses pile foundations. It begins by listing the topics that will be covered, including types of piles, pile spacing, pile caps, load testing, and failures. It then defines a pile foundation as using slender structural members like steel, concrete or timber that are installed in the ground to transfer structural loads to deeper, stronger soil layers. The document goes on to classify piles based on their function, material, and installation method. It describes common pile types such as precast concrete, driven steel, and cast-in-place piles. The document provides details on pile uses, selection factors, and installation procedures.
Combine piled raft foundation (cprf)_Er.Karan ChauhanEr.Karan Chauhan
Combine Piled Raft Foundation(CPRF) is an emerging type of new foundation techniques in High rise buildings and skyscraper which raft as a shallow foundation and pile as deep foundation works sharing the total load and reduce settlement and bending moment. the modern approach of design philosophy is included in post graduation level with soil structure interaction of CPRF and this will use to understand the basic concept regarding it.
This document provides guidance on the design of lacing and battens for built-up compression members. It discusses the key design considerations and calculations for both single and double lacing systems, including the angle of inclination, slenderness ratio, effective lacing length, bar width and thickness. Similar guidelines are given for battens, covering spacing, thickness, effective depth, transverse shear and overlap. The document also includes an example problem on designing a slab foundation for a column with given load and material properties.
1) Two-way slabs are slabs that require reinforcement in two directions because bending occurs in both the longitudinal and transverse directions when the ratio of longest span to shortest span is less than 2.
2) The document discusses various types of two-way slabs and design methods, focusing on the direct design method (DDM).
3) Using the DDM, the total factored load is first calculated, then the total factored moment is distributed to positive and negative moments. The moments are further distributed to column and middle strips using factors that consider the slab and beam properties.
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.
The document discusses retaining walls and includes:
- Definitions of retaining walls and their parts
- Common types of retaining walls including gravity, semi-gravity, cantilever, counterfort and bulkhead walls
- Earth pressures like active, passive and at rest pressures
- Design principles for stability against sliding, overturning and bearing capacity
- Drainage considerations for retaining walls
- Theories for analyzing earth pressures like Rankine and Coulomb's theories
- Sample design calculations and problems for checking stability of retaining walls
The document discusses the design of a combined footing to support two columns. It first defines what a combined footing is and why it is used. It then describes the types of combined footings and the forces acting on it. The document provides the design steps for a rectangular combined footing, which include determining dimensions, reinforcement requirements, and design checks. As an example, it shows the detailed design of a rectangular combined footing supporting two columns with loads of 450kN and 650kN respectively. The design includes calculating dimensions, reinforcement, development lengths, and design checks.
This document provides information on doubly reinforced concrete beams. It introduces the concept of doubly reinforced beams, which have reinforcement in both the tension and compression zones. This allows for an increased moment of resistance compared to singly reinforced beams. The key advantages of doubly reinforced beams are that they can be used when the applied moment exceeds the capacity of a singly reinforced beam, when beam depth cannot be increased, or when reversal of stresses may occur. The document includes stress diagrams, design concepts, and differences between singly and doubly reinforced beams.
Piles are deep foundations used to transfer structural loads through weak or wet soils to stronger soils below. Piles can be classified based on function (end bearing, friction, tension), material (concrete, timber, steel), or installation method (driven, cast-in-place). Key factors in pile design include soil properties, load types, and groundwater conditions. The ultimate load capacity of a pile considers end bearing and side friction, while the allowable load uses a factor of safety. Dynamic testing and soil parameters can be used to estimate pile capacities.
Question and Answers on Terzaghi’s Bearing Capacity Theory (usefulsearch.org)...Make Mannan
This document contains solved examples of questions on bearing capacity from previous year question papers. It includes 6 questions calculating the ultimate bearing capacity, safe bearing capacity, and size of footing for given soil properties and loading conditions using Terzaghi and general shear failure theories. The properties provided are unit weight, cohesion, friction angle, and bearing capacity factors. Depths, widths, loads, and factors of safety are also given. The step-by-step workings and solutions are shown for each question.
This document discusses the design of beams. It defines different types of beams like floor beams, girders, lintels, purlins, and rafters. It describes how beams are classified based on their support conditions as simply supported, cantilever, fixed, or continuous beams. Commonly used beam sections include universal beams, compound beams, and composite beams. The document also covers plastic analysis of beams, classification of beam sections, and failure modes of beams.
The document provides details on the design procedure for beams. It discusses estimating loads, analyzing beams to determine shear forces and bending moments, and designing beams. The design process involves selecting the beam size and shape, calculating the effective span, determining critical moments and shears, selecting reinforcement, and checking requirements such as shear capacity, deflection limits, and development lengths. An example problem demonstrates designing a singly reinforced concrete beam with a span of 5 meters to support a working live load of 25 kN/m.
Tension members are structural elements subjected to direct tensile loads. Their strength depends on factors like length of connection, size and spacing of fasteners, cross-sectional area, fabrication type, connection eccentricity, and shear lag. Failure can occur through gross section yielding, net section rupture, or block shear. Design involves selecting a member with sufficient gross area to resist factored loads in yielding, then checking strength considering net section rupture and block shear failure modes.
The document discusses different methods of designing reinforced concrete elements:
1. Modular ratio (working stress) method, which assumes elastic behavior and uses factors of safety. It was the first accepted method but has limitations.
2. Load factor method, which avoids modular ratio and uses load factors to account for ultimate loads. However, it does not consider serviceability.
3. Limit state method, adopted in modern codes, which considers both ultimate and serviceability limit states using partial safety factors applied to loads and material strengths. It provides a comprehensive solution for safety and serviceability.
This document describes cantilever retaining walls. It defines a retaining wall as a structure that maintains ground surfaces at different elevations on either side. Cantilever retaining walls consist of a stem supported by a base and resist lateral forces through bending. The document discusses the types of forces acting on retaining walls, methods for calculating lateral earth pressures, and design considerations for stability, soil pressure distribution, and reinforcement in the stem, toe slab, and heel slab.
The document describes the design of a stepped footing to support a column with an unfactored load of 800 kN. A square footing with dimensions of 2.1m x 2.1m is designed with two 300mm steps. Reinforcement of #12 bars at 150mm c/c is provided. Checks are performed for bending moment, one-way shear, two-way shear, and development length which all meet code requirements. Therefore, the stepped footing design is adequate to support the given column load.
Retaining walls are used at the Shraddha Vivanta Residency construction site in Mumbai for two main purposes. Cantilever retaining walls around 3.5 meters deep allow for a basement and four floors of stacked parking underneath the residential building. Additional retaining walls surround underground water tanks for suction and firefighting. The walls are located along the building perimeter and around the tank areas. Proper waterproofing of the retaining walls is important given their underground locations.
The document discusses the reinforcement requirements and design process for axially loaded columns. It provides guidelines on the minimum longitudinal and transverse reinforcement, including the pitch and diameter of lateral ties. Examples are given to calculate the ultimate load capacity of rectangular and circular columns based on the grade of concrete and steel. Design assumptions and checks for minimum eccentricity are also outlined.
This document provides information on designing and detailing combined footings with steel reinforcement. It begins with defining what a combined footing is and the types of combined footings. It then outlines the design steps which include proportioning the footing size, calculating shear forces and bending moments, designing the longitudinal and transverse reinforcement, and preparing bar bending schedules. An example is provided to demonstrate the full design of a combined footing with a central beam joining two columns. The summary includes designing the slab and beam sections, checking development length and shear capacity, and determining the required steel reinforcement.
- The document discusses the design of a combined footing to support two columns carrying loads of 700 kN and 1000 kN respectively.
- A trapezoidal combined footing of size 7.2m x 2m is designed to support the loads and transmit them uniformly to the soil.
- Longitudinal and transverse reinforcement is designed for the footing and a central beam is included to join the two columns. Detailed design calculations and drawings of the footing and beam are presented.
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.
The document provides details on the design of a reinforced concrete column footing to support a column load of 1100kN from a 400mm square column. It describes the design process which includes determining the footing size, calculating bending moment, reinforcement requirements, checking shear capacity and development length. The design example shows a 3.5m x 3.5m square footing with 12mm diameter bars at 100mm c/c is adequate to support the given load based on the specified material properties and design codes. Reinforcement and footing details are also provided.
The document provides details on the design of a reinforced concrete column footing to support a column with a load of 1100kN. It includes calculating the footing size as a 3.5m x 3.5m square to support the load, determining the reinforcement with 12mm diameter bars at 100mm spacing, and checking that the design meets requirements for bending capacity, shear strength, and development length. The step-by-step worked example shows how to analyze and detail the reinforcement of the column footing.
Gantry girder
Gantry girder or crane girder hand operated or electrically operated overhead cranes in industrial building such as factories, workshops, steel works, etc. to lift heavy materials, equipment etc. and carry them from one location to other , within the building
The GANTRY GIRDER spans between brackets attached to columns, which may either be of steel or reinforced concrete. Thus the span of gantry girder is equal to centre to centre spacing of columns. The rails are mounted on gantry girders.
Loads acting on gantry girder
Gantry girder, having no lateral support in its length (laterally unsupported) has to withstand the following loads:
1. Vertical loads from crane :
Self weight of crane girder
Hook load
Weight of crab (trolley)
2. Impact load from crane :
As the load is lifted using the crane hook and moved from one place to another, and released at the required place, an impact is felt on the gantry girder.
3. Longitudinal horizontal force (Drag force) :
This is caused due to the starting and stopping of the crane girder moving over the crane rails, as the crane girder moves longitudinally, i.e. in the direction of gantry girder.
This force is also known as braking force, or drag force.
This force is taken equal to 5% of the static wheel loads for EOT or hand operated cranes.
4. Lateral load (Surge load) :
Lateral forces are caused due to sudden starting or stopping of the crab when moving over the crane girder.
Lateral forces are also caused when the crane is dragging weights across the' floor of the shop.
Types of gantry girders
Depending upon the span and crane capacity, there can be many forms of gantry girders. Some commonly used forms are shows in fig .
Rolled steel beams with or without plates, channels or angles are normally used for spans up to 8m and for cranes up to 50kN capacity.
Plate girder are suitable up to span 6 to 10 m.
Plate girder with channels, angles, etc. can be used for spans more than 10m
Box girder are used foe spans more than 12m.
This document discusses the design of an isolated column footing, including:
1) Types of isolated column footings and factors that influence footing size like bearing capacity of soil.
2) Key sections to check for bending moment, shear, and development length.
3) Reinforcement requirements.
4) An example problem where a rectangular isolated sloped footing is designed for a column carrying an axial load of 2000 kN. Design checks are performed for footing size, bending moment, shear, development length, and reinforcement.
The document summarizes the analysis and design of a steel flyover at Vandalur Junction by a group of batch members supervised by an assistant professor. It includes the introduction, objectives, scope, literature review, methodology, materials used, design of the deck slab, longitudinal girders, cross girders, piers, pile foundation and conclusion. The key elements - deck slab, girders, piers and pile foundation - were designed according to codes like IRC and IS using software. The design aims to reduce traffic congestion at the junction by providing a grade separated flyover structure.
One way slab is designed for an office building room measuring 3.2m x 9.2m. The slab is 150mm thick with 10mm diameter reinforcement bars spaced 230mm centre to centre. It is simply supported on 300mm thick walls and designed to support a 2.5kN/m2 live load. Reinforcement provided meets code requirements for minimum area and spacing. Design checks for cracking, deflection, development length and shear are within code limits.
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.
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.
This document provides the design of a rectangular water tank with a capacity of 2500 cubic meters. It includes:
1) Design of the roof slab as a flat slab with columns spaced 5 meters apart and a thickness of 240mm.
2) Design of columns with a size of 350mm and reinforcement of 6 bars of 16mm diameter.
3) Design of the vertical walls with a thickness of 230mm at the base reducing to 180mm in the middle. Reinforcement of 16mm diameter bars at 125mm centers is provided.
4) Checks for crack width for the columns and walls show the crack width is less than the permissible 0.2mm.
This document details the planning, analysis, and design of the academic block of a high school building. It includes the dimensions and specifications of the building components. Load calculations are performed to determine dead and live loads. The key structural elements - slab, beam, column, footing, and staircase - are designed based on the loading. Reinforcement details are provided for each element. The column with the maximum load of 1588.25 kN and beam with maximum bending moment of 166.526 kNm are identified. Manual calculations are included for design verification. The project helps gain knowledge of structural planning and design using software and code-based manual methods.
Design of Steel Grillage Foundation for an AuditoriumIRJET Journal
This document describes the design of a grillage foundation for an auditorium. Some key points:
- The foundation will consist of a grid structure of steel beams and columns supported by a concrete slab. This type of foundation is economical for transferring heavy loads to soil with low bearing capacity.
- The members of the grillage foundation like beams, columns, grid slab, footing and slab will be manually designed according to IS 456-2000 code specifications.
- The two-way slab will be designed to be 110mm thick with main reinforcement and distribution bars. The slab design will be checked for shear and deflection.
- The grid slab will be 3m x 3m with ribs 1300mm deep
Design of shallow foundation slide sharezameer1979
1. The document discusses various types of shallow foundations including spread footings, combined footings, strap or cantilever footings, and mat or raft foundations.
2. Design of foundations involves determining the safe bearing capacity of soil and proportioning the size, thickness, and reinforcement of footings based on bending moment and shear force calculations.
3. Numerical examples show how to calculate the required width, length, or depth of different footings given soil properties and applied loads using bearing capacity equations.
The document summarizes the design of a 787.8m long flyover with 22 piers and 2 abutments located in Mathura, India. It includes the design of the deck slab, longitudinal and cross girders, piers, and foundations. Pigeaud's and Courbon's methods were used to design the deck slab and girders respectively. Reinforcement details are provided for all elements following Indian design codes. The flyover has a 250mm thick deck slab with 16mm and 12mm bars and 1.575m deep longitudinal girders with 32mm bars. Piers are 2-2.5m in diameter with 28mm or 25mm longitudinal bars. Foundations are 10.
The document presents the design of a post-tensioned prestressed concrete tee beam and slab bridge deck. Key details include:
- The bridge will have an effective span of 30m and width of 7.5m with 600mm kerbs and 1.5m footpaths on each side.
- The project team will design the bridge to meet Class AA loading standards for a national highway.
- The bridge will have 4 main girders spaced at 2.5m intervals with a 250mm thick deck slab cast between them.
- The document outlines the design process for the interior slab panel, longitudinal girders, and calculation of design moments and shear forces. Properties of the main girder cross
This resource material is exclusively for the purpose of knowledge dissemination for the use of Civil engineering Fraternity, professionals & students.
This file contains state of art techniques adopted & practiced as per IS456 code provisions for analysis design & detailing of flat slab structural systems.
The presentation aims to provide clear,concise, technical details of flat slabs design.
The presentation deals with structural actions & behavior of flat slabs with visual representations obtained through finite element analysis.
The knowledge gained can be used for designing building structures frequently encountered in construction.
The presentation covers an important feature of slab systems supported on rigid & flexible support & clearly demarcates the minimum beam dimensions required to consider the supports to be either rigid or flexible.
The presentation alsoincludes clear technical drawings to highlight the importance of detailing w.r.t. rebar lay out - positioning & curtailment. Typical section drawing through middle & column strips are also included for visualizing rebar patterns in 3 -d views.
This presentation is an outcome of series of lectures for undergrad & grad students studying in civil engineering.
My next presentation would be on Analysis & design of deep beams.
Kindly mail me ( vvietcivil@gmail.com) your questions & valuable feedback.
This is an overview of my current metallic design and engineering knowledge base built up over my professional career and two MSc degrees : - MSc in Advanced Manufacturing Technology University of Portsmouth graduated 1st May 1998, and MSc in Aircraft Engineering Cranfield University graduated 8th June 2007.
Impartiality as per ISO /IEC 17025:2017 StandardMuhammadJazib15
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An In-Depth Exploration of Natural Language Processing: Evolution, Applicatio...DharmaBanothu
Natural language processing (NLP) has
recently garnered significant interest for the
computational representation and analysis of human
language. Its applications span multiple domains such
as machine translation, email spam detection,
information extraction, summarization, healthcare,
and question answering. This paper first delineates
four phases by examining various levels of NLP and
components of Natural Language Generation,
followed by a review of the history and progression of
NLP. Subsequently, we delve into the current state of
the art by presenting diverse NLP applications,
contemporary trends, and challenges. Finally, we
discuss some available datasets, models, and
evaluation metrics in NLP.
This study Examines the Effectiveness of Talent Procurement through the Imple...DharmaBanothu
In the world with high technology and fast
forward mindset recruiters are walking/showing interest
towards E-Recruitment. Present most of the HRs of
many companies are choosing E-Recruitment as the best
choice for recruitment. E-Recruitment is being done
through many online platforms like Linkedin, Naukri,
Instagram , Facebook etc. Now with high technology E-
Recruitment has gone through next level by using
Artificial Intelligence too.
Key Words : Talent Management, Talent Acquisition , E-
Recruitment , Artificial Intelligence Introduction
Effectiveness of Talent Acquisition through E-
Recruitment in this topic we will discuss about 4important
and interlinked topics which are
Data Communication and Computer Networks Management System Project Report.pdfKamal Acharya
Networking is a telecommunications network that allows computers to exchange data. In
computer networks, networked computing devices pass data to each other along data
connections. Data is transferred in the form of packets. The connections between nodes are
established using either cable media or wireless media.
We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
Online train ticket booking system project.pdfKamal Acharya
Rail transport is one of the important modes of transport in India. Now a days we
see that there are railways that are present for the long as well as short distance
travelling which makes the life of the people easier. When compared to other
means of transport, a railway is the cheapest means of transport. The maintenance
of the railway database also plays a major role in the smooth running of this
system. The Online Train Ticket Management System will help in reserving the
tickets of the railways to travel from a particular source to the destination.
2. 2
Summary Sheet
Session Number :
Date :
Subject Expert :
8
14.05.2007-
Dr. M.C. NatarajaDr. M.C. Nataraja
Professor
Department of Civil Engineering,
Sri Jayachamarajendra College of Engineering,
Mysore – 570 006.
Phone:0821-2343521, 9880447742
E-mail: nataraja96@yahoo.com
3. 3
Learning Outcomes:
• After this students will be able design and detailAfter this students will be able design and detail
combined footings through drawing and bar bendingcombined footings through drawing and bar bending
schedule. This is for Part B and is one full questionschedule. This is for Part B and is one full question
for about 70 marks.for about 70 marks.
Design and Detailing of
steel in Combined Footings
4. 4
Footings
The function of a footing or a foundation is to
transmit the load form the structure to the
underlying soil.
The choice of suitable type of footing depends on
the depth at which the bearing strata lies, the soil
condition and the type of superstructure.
5. 5
Combined footing
Whenever two or more columns in a straight line are carried on
a single spread footing, it is called a combined footing.
Isolated footings for each column are generally the
economical.
Combined footings are provided only when it is absolutely
necessary, as
1. When two columns are close together, causing overlap
of adjacent isolated footings
2. Where soil bearing capacity is low, causing overlap of
adjacent isolated footings
3. Proximity of building line or existing building or sewer,
adjacent to a building column.
6. 6
P2
l a2a1
x R
Combined footing with
loads
P1
L/2L/2
Types of combined
footings
Property line
+
+
+
b
7. 7
2. Slab and beam type
3. Strap type
Types of combined footing
1. Slab type
8. 8
• The combined footing may be rectangular,
trapezoidal or Tee-shaped in plan.
The geometric proportions and shape are so fixed that the
centeroid of the footing area coincides with the resultant of the
column loads. This results in uniform pressure below the entire
area of footing.
• Trapezoidal footing is provided when one column load is much
more than the other. As a result, the both projections of footing
beyond the faces of the columns will be restricted.
• Rectangular footing is provided when one of the projections of
the footing is restricted or the width of the footing is restricted.
9. 9
Rectangular
combined footing
• Longitudinally, the footing acts as an upward loaded
beam spanning between columns and cantilevering
beyond. Using statics, the shear force and bending
moment diagrams in the longitudinal direction are drawn.
Moment is checked at the faces of the column. Shear
force is critical at distance ‘d’ from the faces of columns
or at the point of contra flexure. Two-way shear is
checked under the heavier column.
• The footing is also subjected to transverse bending and
this bending is spread over a transverse strip near the
column.
11. 11
d d
d/2
1 2 3 4 5 6
1 2 3 4 5 6
Section 1-1, 2-2, 5-5, and 6-6 are sections for critical moments
Section 3-3, 4-4 are sections for critical shear (one way)
Section for critical two way shear is abcd
a b
d c
CRITICAL SECTIONS FOR MOMENTS AND SHEAR
13. 13
Design Steps
• Locate the point of application of the column
loads on the footing.
• Proportion the footing such that the resultant of loads
passes through the center of footing.
• Compute the area of footing such that the allowable soil
pressure is not exceeded.
• Calculate the shear forces and bending moments at the
salient points and hence draw SFD and BMD.
• Fix the depth of footing from the maximum bending
moment.
• Calculate the transverse bending moment and design
the transverse section for depth and reinforcement.
Check for anchorage and shear.
14. 14
Design Steps -Contd.,
• Check the footing for longitudinal shear and hence
design the longitudinal steel
• Design the reinforcement for the longitudinal
moment and place them in the appropriate
positions.
• Check the development length for longitudinal steel
• Curtail the longitudinal bars for economy
• Draw and detail the reinforcement
• Prepare the bar bending schedule
15. 15
Detailing
Detailing of steel (both longitudinal and transverse) in a
combined footing is similar to that of conventional beam-
SP-34
Detailing requirements of beams and slabs should be
followed as appropriate-SP-34
16. 16
Design of combined footing –
Slab and Beam type
1. Two interior columns A and B carry 700 kN and 1000
kN loads respectively. Column A is 350 mm x 350 mm
and column B is 400 mm X 400 mm in section. The
centre to centre spacing between columns is 4.6 m.
The soil on which the footing rests is capable of
providing resistance of 130 kN/m2
. Design a combined
footing by providing a central beam joining the two
columns. Use concrete grade M25 and mild steel
reinforcement.
17. 17
Draw to a suitable scale the following
1. The longitudinal sectional elevation
2. Transverse section at the left face of the heavier
column
3. Plan of the footing
Marks 60
18. 18
Solution: Data
fck = 25 Nlmm2
,
fy= 250 N/mm2
,
fb = l30 kN/m2
(SBC),
Column A = 350 mm x 350 mm,
Column B = 400 mm x 400 mm,
c/c spacing of columns = 4.6 m,
PA = 700 kN and PB = 1000 kN
Required: To design combined footing with central beam
joining the two columns.
Ultimate loads
PuA= 1.5 x 700 = 1050 kN, PuB = 1.5 x 1000 = 1500 kN
19. 19
Proportioning of base size
Working load carried by column A = PA = 700 kN
Working load carried by column B = PB = 1000 kN
Self weight of footing 10 % x (PA + PB) = 170 kN
Total working load = 1870 kN
Required area of footing = Af = Total load /SBC
=1870/130 = 14.38 m2
Let the width of the footing = Bf = 2m
Required length of footing = Lf = Af /Bf = 14.38/2 = 7.19m
Provide footing of size 7.2m X 2m,Af = 7.2 x 2 = 14.4 m2
20. 20
Then x = (PB x 4.6)/(PA + PB) = (1000 x 4.6)/(1000 +700)
= 2.7 m from column A.
If the cantilever projection of footing beyond column A is ‘a’
then, a + 2.7 = Lf /2 = 7.2/2, Therefore a = 0.9 m
Similarly if the cantilever projection of footing beyond B is 'b'
then, b + (4.6-2.7) = Lf /2 = 3.6 m,
Therefore b = 3.6 - 1.9 = 1.7 m
The details are shown in Figure
For uniform pressure distribution the C.G. of
the footing should coincide with the C.G. of
column loads. Let x be the distance of C.G.
from the centre line of column A
21. 21
C
700 kN 1000 kN
4600 mm b=1700a=900
x R
Combined footing with loads
A B D
pu=177 kN/m2
wu=354 kN/m
22. 22
Rectangular Footing with Central Beam:-
Design of Bottom slab.
Total ultimate load from columns = Pu
= 1.5(700 + 1000) = 2550 kN.
Upward intensity of soil pressure wu
= P/Af
= 2550/14.4 = 177 kN/m2
Design of slab
Intensity of Upward pressure = wu
=177 kN/m2
Consider one meter width of the slab (b=1m)
Load per m run of slab at ultimate = 177 x 1 = 177 kN/m
Cantilever projection of the slab (For smaller column)
=1000 - 350/2 = 825 mm
Maximum ultimate moment = 177 x 0.8252
/2 = 60.2 kN-m.
23. 23
For M25 and Fe 250, Q u max
= 3.71 N/mm2
Required effective depth = √ (60.2 x 106
/(3.71 x 1000)) = 128 mm
Since the slab is in contact with the soil clear cover of 50 mm is
assumed.
Using 20 mm diameter bars
Required total depth = 128 + 20/2 + 50 =188 mm say 200 mm
Provided effective depth = d = 200-50-20/2 = 140 mm
pu=177 kN/m2
1m
0.825 m
Slab design-Contd.,
1m
0.35m
24. 24
To find steel
Mu
/bd2
=3.07<3.73, URS
Mu=0.87 fy Ast[d-fyAst/(fckb)]
pt
=1.7%
Ast
= 2380 mm2
Use Φ20 mm diameter bar at spacing
= 1000 x 314 / 2380 = 131.93 say 130 mm c/c
Area provided =1000 x 314 / 130 = 2415 mm2
25. 25
Check the depth for one - way
shear considerations- At ‘d’ from face
Design shear force=Vu
=177x(0.825-0.140)=121kN
Nominal shear stress=τv
=Vu
/bd=121000/
(1000x140)=0.866MPa
Permissible shear stress
Pt
= 100 x 2415 /(1000 x 140 ) = 1.7 %, τuc
= 0.772 N/mm2
Value of k for 200 mm thick slab =1.2
Permissible shear stress = 1.2 x 0.772 = 0.926 N/mm2
τuc
> τv
and hence safe
The depth may be reduced uniformly to 150 mm at the
edges.
26. 26
Check for development length
Ldt
= [0.87 x 250 / (4 x 1.4)]Ф =39 Ф
= 39 x 20 = 780 mm
Available length of bar=825 - 25 = 800mm
> 780 mm and hence safe.
Transverse reinforcement
Required Ast
=0.15bD/100
=0.15x1000 x 200/100 = 300mm2
Using Ф8 mm bars, Spacing=1000x50/300
= 160 mm
Provide distribution steel of Ф8 mm at 160 mm
c/c,<300, <5d
pu=177 kN/m2
1m
0.825 m
27. 27
Design of Longitudinal Beam
Load from the slab will be transferred to the beam.
As the width of the footing is 2 m, the net upward soil
pressure per meter length of the beam
= wu
= 177 x 2 = 354 kN/m
Shear Force and Bending Moment
VAC
= 354 x 0.9 =318.6 kN, VAB
= 1050-318.6 =731.4 kN
VBD
= 354 x 1.7 = 601.8kN, VBA
= 1500-601.8 = 898.2 kN
Point of zero shear from left end C
X1
= 1050/354 = 2.97m from C or
X2
= 7.2-2.97 = 4.23 m from D
28. 28
Maximum B.M. occurs at a distance of 4.23 m from D
MuE
= 354 x 4.232
/ 2 - 1500 (4.23 - 1.7) = -628 kN.m
Bending moment under column A= MuA
=354x0.92
/2 =
143.37 kN.m
Bending moment under column B = MuB
= 354 x 1.72
= 511.5 kN-m
Let the point of contra flexure be at a distance x from
the centre of column A
Then, Mx
= I050x - 354 (x + 0.9 )2
/ 2 = 0
Therefore x = 0.206 m and 3.92 m from column A
i.e. 0.68 m from B.
29. 29
1050 kN 1500 kN
354 kN/m
0.9 m 1.7 m4.6 m
C
A B
D
E
ME=628 kN-m
MA=143.37 kN-m
+
_
.+
X=0.206 m 0.68m
MB=511.5 kN-mBMD at Ultimate
V1=318.6 kN
V4=601.8 kN
V2=731.4 kN
V3=898.2 kN
SFD at Ultimate
+
+
-
X1=2.97
m
X2=4.23
m
E
-
30. 30
Depth of beam from B.M.
The width of beam is kept equal to the maximum
width of the column i.e. 400 mm. Determine the
depth of the beam where T- beam action is not available.
The beam acts as a rectangular section in the cantilever
portion, where the maximum positive moment = 511.5 kN/m.
d =√ (511.5 x 106
/ (3.73 x 400)) = 586 mm
Provide total depth of 750 mm. Assuming two rows of bars
with effective cover of 70 mm.
Effective depth provided = d= 750-70 = 680 mm (Less than
750mm and hence no side face steel is needed.
31. 31
Check the depth for Two-way Shear
The heaver column B can punch through the footing only if
it shears against the depth of the beam along its two
opposite edges, and along the depth of the slab on the
remaining two edges. The critical section for two-way
shear is taken at distance d/2 (i.e. 680/2 mm) from the
face of the column. Therefore, the critical section will be
taken at a distance half the effective depth of the slab
(ds/2) on the other side as shown in Fig.
32. 32
350 x 350 400 x 400400
7200 mm
2000
mm
+
0.8m
2.7m 1.9m
1.5m
0.825m
A B
a=0.9m b=1.7m4.6m
B=400 x 400 mm
2000B
D
D+db
D+ds
D+db/2
33. 33
In this case b=D=400 mm, db
=680 mm, ds
=140 mm
Area resisting two - way shear
= 2(b x db
+ ds
x d s
) + 2 (D + d b
)ds
= 2 (400 x 680+ 140 x 140) + 2(400+680) 140= 885600 mm2
Design shear=Pud
= column load – W u
x area at critical section
= 1500 - 177 x(b + ds
) x (D + db
)
=1500-177 x (0.400+0.140) x (0.400+ 0.680)
=1377.65kN
τv
=Pud
/bo
d= 1377.65x1000/885600=1.56 MPa
Shear stress resisted by concrete = τuc
= τuc
x K s
where, τuc
= 0.25 √ f ck
= 0.25√ 25 = 1.25 N/mm2
K s
= 0.5 + d / D = 0.5 + 400/400 = 1.5 ≤ 1 Hence K s
= 1
τuc =
1 x 1.25 = 1.25 N/mm2 .
Therefore Unsafe
34. 34
Area of Steel: Cantilever portion BD
Length of cantilever from the face of column
=1.7- 0.4/2 = 1.5 m.
Ultimate moment at the face of column
=354x1.52
/2=398.25 kN-m
Mumax
= 3.71 x 400 x 6802
x 10 -6
= 686 kN-m > 398.25 kN-m
Therefore Section is singly reinforced.
Mu
/bd2
=398.25x106
/(400x6802
) =2.15 <3.73, URS
Pt
=1.114%
A st
=3030 mm2
, Provide 3-Φ32 mm + 4-Φ16 mm at bottom face,
Area provided = 3217 mm2
Ldt
= 39 x 32 =1248 mm
35. 35
Curtailment
All bottom bars will be continued up to the end of
cantilever. The bottom bars of 3 - Ф 32 will be
curtailed at a distance d (= 680 mm) from the
point of contra flexure (λ = 680 mm) in the portion BE with its
distance from the centre of support equal to 1360 mm from B.
Cantilever portion AC
Length of cantilever from the face of column =900-350/2 = 725 mm
Ultimate moment = 354 x 0.7252 /2 = 93 kN-m
Mu/bd2
=93x106
/(400x6802) =0.52 <3.73, URS
Pt=0.245% (Greater than minimum steel)
Ast =660 mm2
Provide 4 - Ф 16 mm at bottom face, Area provided = 804 mm2
Continue all 4 bars of 16 mm diameter through out at bottom.
36. 36
Region AB between points of contra flexures
The beam acts as an isolated T- beam.
bf = [Lo/( Lo / b +4)] + bw, where,
L o
= 4.6 - 0.206 - 0.68 = 3.714 m = 3714 mm
b= actual width of flange = 2000 mm, b w
= 400 mm
bf
= [3714/(3714/2000+4) + 400] =1034mm < 2000mm
Df
=200 mm, Mu
= 628 kN-m
Moment of resistance Muf
of a beam for x u
= D f
is :
Muf
= [0.36 x 25 x1034 x 200(680 - 0.42x200)]x10-6
= 1109 kN.m > Mu
( = 628 kN-m)
37. 37
Therefore Xu
<Df
Mu
=0.87fy
Ast
(d - fy
Ast
/fck
bf)
Ast
= 4542 mm2
Provide 5 bars of Ф 32 mm and 3 bars of Ф 16 mm,
Area provided = 4021 + 603 = 4624 mm2
>4542 mm2
pt
= 100 x 4624/(400x680) = 1.7 %
38. 38
Curtailment:
Consider that 2 - Ф 32 mm are to be curtailed
No. of bars to be continued = 3 - Ф16 + 3 - Ф 32
giving area = Ast
=3016 mm2
Moment of resistance of continuing bars
Mur
= (0.87 x 250 x 3016 (680 – ((250 x 3016) / (25 x 400) x 10-6
= 396.6 kN-m
Let the theoretical point of curtailment be at a distance x from
the free end C,
Then, Muc
= Mur
Therefore -354 x2
/ 2 + 1050 (x- 0.9) = 396.6
x2
-5.93x + 7.58 =0, Therefore x = 4.06m or 1.86m from C
39. 39
Actual point of curtailment = 4.06 + 0.68 = 4.74 m
from C or 1.86 - 0.68 = 1.18 m from C
Terminate 2 - Φ 32 mm bars at a distance of 280
mm (= 1180 - 900) from the column A and 760mm
(= 5500 - 4740) from column B. Remaining bars 3 -
Φ 32 shall be continued beyond the point of
inflection for a distance of 680 mm i.e. 460 mm
from column A and up to the outer face of column
B. Remaining bars of 3 - Φ 16 continued in the
cantilever portion.
40. 40
Design of shear reinforcement
Portion between column i.e. AB
In this case the crack due to diagonal tension will occur
at the point of contra flexure because the distance of
the point of contra flexure from the column is less than
the effective depth d(= 680mm)
(i) Maximum shear force at B = Vumax
= 898.2 kN
Shear at the point of contra flexure
= VuD
- 898.2-354 x 0.68 = 657.48 kN
τv
=657000/(400x680) =2.42 MPa < τc,max.
41. 41
Area of steel available 3 - Φ 16 + 3 - Φ 32 ,
Ast
= 3016 mm2
pt
= 100 x 3016 / (400 x 680) = 1.1%
τc
=0.664MPa
τv
> τc
Design shear reinforcement is required.
Using 12 mm diameter 4 - legged stirrups,
Spacing= [0.87 x 250x(4x113)] /(2.42-0.664)x400 =139 mm
say 120 mm c/c
Zone of shear reinforcements between τv
to τc
= m from support B towards A
42. 42
(ii) Maximum shear force at A
= Vu max
= 731.4 kN.
Shear at the point contra flexure = VuD
= 731.4 - 0.206 x
354 = 658.5 kN
τv
=658500/(400x680) =2.42MPa < τc,max.
Area of steel available = 4624 mm2
, pt
= 100 x 4624 / (400 *
680) = 1.7 %
τuc
= 0.772 N/ mm2
,
τv
> τc
43. 43
Design shear reinforcement is required.
Using 12 mm diameter 4 - legged stirrups,
Spacing = 0.87 x 250 x (4 x 113) /(2.42-0.774)x400
=149 mm say 140 mm c/c
Zone of shear reinforcement.
From A to B for a distance as shown in figure
For the remaining central portion of 1.88 m provide
minimum shear reinforcement using 12 mm diameter 2 -
legged stirrups at
Spacing , s = 0.87 x 250 x (2 x 113)/(0.4 x 400)=307.2
mm, Say 300 mm c/c< 0.75d
44. 44
Cantilever portion BD
Vumax
= 601.8kN,
VuD
=601.8-354(0.400/2 + 0.680) = 290.28kN.
τv
=290280/(400x680) =1.067MPa < τc,max.
Ast
= 3217 mm2
and pt
= 100 x 3217/(400 x 680) = 1.18%
τc
=0.683N/mm2
(Table IS:456-2000)
τv
> τc
and τv
- τc
<0.4. Provide minimum steel.
Using 12 mm diameter 2- legged stirrups,
Spacing = 0.87 x 250 x (2 x 113) /(0.4x400) =307.2 mm
say 300 mm c/c
45. 45
Cantilever portion AC
Minimum shear reinforcement of Ф 12 mm
diameters 2 - legged stirrups at 300mm c/c will
be sufficient in the cantilever portions of the
beam as the shear is very less.
46. 46
350x350 400x400
Φ12@300,
2L Stp
Φ12@120,
4L Stp
Φ12@300,
2L Stp
Φ12@140,
4L Stp
Φ12@300,
2L Stp
(5-Φ32 + 3-
Φ16)
3- Φ16
3-Φ32
+
4-Φ16
0.9 m 4.6 m 1.7 m
(3-Φ32 + 3- Φ163- Φ16
Side face
2- Φ12
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