This document discusses the design and analysis of flat slab structures. It begins with an introduction to flat slabs and their uses of column heads and drop panels. The benefits of flat slabs are then outlined, including flexibility in layout, reduced building height, and ease of M&E installation. Design considerations are presented such as structural stiffness, deflection limits, and shear reinforcement. The document analyzes flat slab design methodology including finite element analysis, simplified methods, and equivalent frame analysis. Moment distribution, punching shear, deflection, and detailing of reinforcement mesh are also summarized.
This document discusses the design of flat slab structures. It begins by defining a flat slab as a type of slab supported directly on columns without beams. It then provides details on the types of flat slabs, their common uses in buildings, and benefits such as flexibility in layout and reduced construction time. The document goes on to discuss key design considerations for flat slabs including thickness, drops, column heads, and methods of analysis. It focuses on the direct design method and provides limitations for its use.
Composite structure of concrete and steel.Suhailkhan204
Ā
This document discusses composite structures, which combine steel and concrete materials. The key elements of composite structures are composite deck slabs, beams, and columns, along with shear connectors. Composite structures take advantage of concrete's compressive strength and steel's tensile strength. They provide benefits like increased load capacity, stiffness, fire resistance, and cost savings compared to traditional steel or concrete construction alone. An example project, the Millennium Tower in Vienna, is described. The document analyzes costs and concludes that composite structures are best suited for high-rise buildings due to reduced weight, increased ductility, and savings of around 10% compared to reinforced concrete.
Flat slabs are reinforced concrete slabs that are supported directly by columns without beams. They provide minimum depth, fast construction, and flexible column placement. There are four main types: slabs without drops and with column heads, slabs with drops and without column heads, slabs with both drops and column heads, and typical flat slabs. Column heads increase shear strength while drops increase shear strength and negative moment capacity. Flat slab systems can be either one-way or two-way depending on span ratios and load distribution. Advantages include simple formwork, no beams, and minimum depth, while disadvantages include potential interference from drops.
This document discusses prefabricated modular structures. Some key points:
1. Prefabricated structures have standardized components that are produced off-site in a controlled environment and then transported for assembly. This allows for faster, more efficient construction.
2. Precast concrete offers advantages like higher quality, less weather dependency, and unlimited design possibilities compared to site-cast construction.
3. There are different precast systems like large panel, frame, and lift-slab. Precast components include walls, floors, beams, and more.
This document discusses composite construction, where a prefabricated beam and cast-in-place concrete slab act together as a unit. It defines composite construction and describes its advantages over non-composite construction, including increased stiffness, strength, and span length. The document discusses how shear connectors interconnect the beam and slab to achieve composite action. It provides equations for calculating the effective slab width, section properties of the composite section, and required strength of shear connectors. An example is given for designing a composite slab on a precast reinforced concrete beam.
Structural systems in high-rise buildings have evolved over three generations from the late 18th century to present. Early systems used stone, brick, cast iron and wood. Later systems in the 1850-1940 period used steel frames with concrete. Modern systems from 1940 on use steel cores, outriggers, tube designs, diagrids, and superframes to resist gravity and lateral wind loads. Definitions of high-rise vary but are generally above 35 meters. Drivers for tall buildings include land scarcity, demand for space, and prestige. Innovators like Fazlur Rahman Khan pioneered new efficient systems. Future trends may include taller megatalls over 600 meters using new composite systems and materials.
While Designing a High rise Load & Structural Analysis is major factor to consider. Here we analyzed some data and try to describe briefly. We hope that it will help you lot :) Done by Neeti Lamic, Bayezid, Sykot Hasan
1. Structural systems include architectural structures like buildings that are assemblages of components designed to support loads through interconnected members.
2. Loads on structures can be static like dead loads or dynamic like wind loads, and forces like tension, compression, bending, and shear act on structural members.
3. Common structural forms include trusses, arches, shells, frames, and cable nets which use specific geometries and materials like steel and concrete to transfer loads.
This document discusses the design of flat slab structures. It begins by defining a flat slab as a type of slab supported directly on columns without beams. It then provides details on the types of flat slabs, their common uses in buildings, and benefits such as flexibility in layout and reduced construction time. The document goes on to discuss key design considerations for flat slabs including thickness, drops, column heads, and methods of analysis. It focuses on the direct design method and provides limitations for its use.
Composite structure of concrete and steel.Suhailkhan204
Ā
This document discusses composite structures, which combine steel and concrete materials. The key elements of composite structures are composite deck slabs, beams, and columns, along with shear connectors. Composite structures take advantage of concrete's compressive strength and steel's tensile strength. They provide benefits like increased load capacity, stiffness, fire resistance, and cost savings compared to traditional steel or concrete construction alone. An example project, the Millennium Tower in Vienna, is described. The document analyzes costs and concludes that composite structures are best suited for high-rise buildings due to reduced weight, increased ductility, and savings of around 10% compared to reinforced concrete.
Flat slabs are reinforced concrete slabs that are supported directly by columns without beams. They provide minimum depth, fast construction, and flexible column placement. There are four main types: slabs without drops and with column heads, slabs with drops and without column heads, slabs with both drops and column heads, and typical flat slabs. Column heads increase shear strength while drops increase shear strength and negative moment capacity. Flat slab systems can be either one-way or two-way depending on span ratios and load distribution. Advantages include simple formwork, no beams, and minimum depth, while disadvantages include potential interference from drops.
This document discusses prefabricated modular structures. Some key points:
1. Prefabricated structures have standardized components that are produced off-site in a controlled environment and then transported for assembly. This allows for faster, more efficient construction.
2. Precast concrete offers advantages like higher quality, less weather dependency, and unlimited design possibilities compared to site-cast construction.
3. There are different precast systems like large panel, frame, and lift-slab. Precast components include walls, floors, beams, and more.
This document discusses composite construction, where a prefabricated beam and cast-in-place concrete slab act together as a unit. It defines composite construction and describes its advantages over non-composite construction, including increased stiffness, strength, and span length. The document discusses how shear connectors interconnect the beam and slab to achieve composite action. It provides equations for calculating the effective slab width, section properties of the composite section, and required strength of shear connectors. An example is given for designing a composite slab on a precast reinforced concrete beam.
Structural systems in high-rise buildings have evolved over three generations from the late 18th century to present. Early systems used stone, brick, cast iron and wood. Later systems in the 1850-1940 period used steel frames with concrete. Modern systems from 1940 on use steel cores, outriggers, tube designs, diagrids, and superframes to resist gravity and lateral wind loads. Definitions of high-rise vary but are generally above 35 meters. Drivers for tall buildings include land scarcity, demand for space, and prestige. Innovators like Fazlur Rahman Khan pioneered new efficient systems. Future trends may include taller megatalls over 600 meters using new composite systems and materials.
While Designing a High rise Load & Structural Analysis is major factor to consider. Here we analyzed some data and try to describe briefly. We hope that it will help you lot :) Done by Neeti Lamic, Bayezid, Sykot Hasan
1. Structural systems include architectural structures like buildings that are assemblages of components designed to support loads through interconnected members.
2. Loads on structures can be static like dead loads or dynamic like wind loads, and forces like tension, compression, bending, and shear act on structural members.
3. Common structural forms include trusses, arches, shells, frames, and cable nets which use specific geometries and materials like steel and concrete to transfer loads.
A shear wall is a vertical structural element used to resist horizontal forces such as wind and seismic forces. Shear walls are generally used in high-rise buildings where the effects of wind and seismic forces are more significant. Shear walls are usually provided along both the length and width of buildings and act like vertically-oriented beams that carry earthquake loads downwards to the foundation. Common types of shear walls include reinforced concrete, concrete block, steel, plywood, and mid-ply shear walls. Shear walls must provide the necessary lateral strength to resist horizontal earthquake forces and lateral stiffness to prevent excessive side-sway of the structure.
This document summarizes a lecture on flat slab design and analysis. It discusses key topics such as:
1. Definitions of flat slabs and their components like column strips and middle strips.
2. Methods of analyzing flat slabs including numerical methods and manual methods like the method of substitutive beams.
3. Design considerations for flat slabs including steel distribution above columns, welded mesh reinforcement, loading schemes, and punching shear design.
4. Different types of shear reinforcement that can be used at column heads like links, cages, and bent-up bars.
Framed structures are building skeleton frameworks formed by columns and beams. There are two main types: in-situ reinforced concrete frames and prefabricated frames. Rectangular framed structures use columns and beams arranged at right angles to support floors, walls, and roofs. They are commonly used for multi-story buildings like offices, schools, and hospitals. Framed structures provide large open floor plans and are adaptable to different shapes. Earthquake-resistant features in framed structures include shear walls, moment-resisting frames, and braced structures which resist lateral forces during seismic activity.
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
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.
This report compares design codes for hollow block and ribbed slabs. It includes:
- A comparison of limitations between Egyptian, British, Euro and American codes on rib spacing, slab thickness, and other parameters.
- Solved examples for one-way and two-way slabs according to different codes, finding the Egyptian code most economical.
- Analysis of using one or two cross-ribs, determining one rib at midspan is sufficient.
- Different modeling methods for the slabs in structural analysis software, with minor differences in results.
- Case studies presented for one-way, cantilever, two-way hollow block slabs, and ribbed slabs using
This document discusses ductile detailing of reinforced concrete (RC) frames according to Indian standards. It explains that detailing involves translating the structural design into the final structure through reinforcement drawings. Good detailing ensures reinforcement and concrete interact efficiently. Key aspects of ductile detailing covered include requirements for beams, columns, and beam-column joints to improve ductility and seismic performance. Specific provisions are presented for longitudinal and shear reinforcement in beams and columns, as well as confining reinforcement and lap splices. The importance of cover and stirrup spacing is also discussed.
High Rise Building Structure Systems Types
Slide Contents :
INTRODUCTION
INTRODUCTION TO HIGH-RISE DESIGN
DEMANDS FOR HIGH RISE BUILDING
MATERIAL
TYPES OF SYSTEMS
CONSTRUCTIONAL DETAILS
ADVANTAGES AND DISADVANTAGES
1) The document discusses the analysis and design of a high rise building project submitted by Ishant Kukreja. It includes imposing wind and earthquake loads on the building and analyzing its structural behavior.
2) The structural elements like beams, columns, and shear walls are designed. Beam design, shear reinforcement, and column design results are presented.
3) Future prospects discussed include designing the structure for earthquake loads, designing a staircase, using a hybrid RCC and steel structure, and comparing cost. The project helps expand knowledge in high rise design and analysis considering important loads.
Waffle slabs are reinforced concrete slabs reinforced in two orthogonal directions, forming a ribbed plate. They are characterized by their total edge height, lightening block height, rib spacing, rib thickness, and compression layer thickness. Waffle slabs can adequately support distributed and point loads in two directions. Benefits include flexibility, light weight allowing longer spans, fast construction, slim depths, robustness, vibration control, thermal mass, and durability. Waffle slabs are constructed with ribs forming a grid pattern and solid fills at supports. Larger spans may use post-tensioning or joist construction. Proper design considers loads, materials, deformations, and tile installation compatibility.
Shoring is the construction of a temporary structure to support an unsafe or unstable structure. There are three main types of shoring: raking shores, flying shores, and dead shores. Raking shores use inclined members called rakers to provide lateral support to walls. Flying shores provide temporary support between party walls when an intermediate building is demolished. Dead shores provide vertical support to walls and structures when the lower part of a wall is removed, such as to add an opening.
Stone masonry uses stones bonded together with mortar to construct various building components such as walls, columns, foundations, arches and lintels. Stones are selected based on availability, ease of working, appearance, strength, polishing characteristics and economy. There are two main types of stone masonry - rubble masonry which uses roughly dressed stones with wider joints, and ashlar masonry which uses accurately dressed stones with fine, uniform joints. Rubble masonry includes uncoursed, coursed, random, dry and polygonal styles based on stone arrangement. Ashlar masonry has fine, rough, rock-faced, block and chamfered styles based on stone dressing. Stone
The document discusses structural steel, including its composition, properties, types, and applications in construction. It describes how steel is made from iron with added elements, and its varying properties based on carbon content. The types discussed are mild steel, medium carbon steel, and high carbon steel. Common structural steel applications mentioned include beams, columns, trusses, and framing for buildings like airports and stadiums.
This document provides an overview of different types of retaining walls, including gravity, cantilever, counterfort, sheet pile, and diaphragm walls. It discusses the key components and design considerations for gravity and cantilever retaining walls. Gravity walls rely on their own weight for stability, while cantilever walls consist of a vertical stem with a heel and toe slab acting as a cantilever beam. The document also covers lateral earth pressures, drainage of retaining walls, uses of sheet pile walls, and construction methods for diaphragm walls.
Waffle slab or ribbed slab is a structural component with a flat top surface and grid-like bottom surface containing perpendicular ribs. It has two-directional reinforcement and is used for large spans to avoid many interior columns. The waffle shape is formed by placing pods on the formwork before pouring concrete, leaving ribs containing reinforcement. Waffle slabs provide stiff, lightweight structures suitable for areas requiring low deflection and vibration control like airports and hospitals.
1) High rise buildings are becoming more common due to scarcity of land and demand for space. They are defined differently but generally refer to buildings over 15 meters tall.
2) Foundations for high rise buildings include shallow foundations like spread footings and mat foundations, and deep foundations like piles. Piles transfer load through end bearing or friction along their length.
3) Structural systems for high rise buildings must resist both gravity and lateral loads. Interior systems include rigid frames and shear walls. Exterior systems such as tube and diagrid systems resist loads along the building perimeter.
This document provides details on the design and construction of flat slab structures. It discusses the benefits of flat slabs such as flexibility in layout, reduced building height and faster construction. Key considerations for design include wall and column placement, structural layout optimization, deflection checks, crack control and punching shear. Analysis involves dividing the slab into strips and determining moment and shear distributions. Reinforcement is arranged in two directions and detailing includes reinforcement lapping and service penetrations.
The document discusses tube frame structures for tall buildings. Tube frame structures were introduced by Fazlur Khan and involve a hollow cantilever tube perpendicular to the ground. They allow for buildings over 40 stories tall with configurations including framed tubes, braced tubes, tube-in-tube, and bundled tubes. Tube frame structures provide benefits like increased structural rigidity and regular column placement but also have disadvantages like reduced window size and occurrence of shear lag effects.
This document discusses composite construction and cambering of steel beams. It provides information on:
1) The composite construction process including use of composite metal decking, shear connectors, and concrete pouring to create a composite floor system that is stronger and stiffer than steel alone.
2) The advantages of composite construction such as reduced steel needs, lighter weight, and increased spans.
3) The cambering process of inducing a slight curvature in steel beams to compensate for deflection under loads in order to achieve a level floor slab.
4) When cambering is appropriate such as for filler beams, and when it is not such as for moment connected beams. Alternative methods to cambering like
This document discusses the analysis of singly and doubly reinforced concrete beam sections. It provides definitions and design approaches for singly reinforced, doubly reinforced, and flanged beam sections. The key steps in the design process are outlined, including calculating loads and moments, checking for section type, sizing tension and compression reinforcement, and designing shear reinforcement. Design examples are provided for a singly reinforced and a doubly reinforced concrete beam according to BS 8110 design code standards.
This document discusses the analysis of singly and doubly reinforced concrete beam sections. It begins by defining singly reinforced sections as having tension reinforcement only, while doubly reinforced sections have reinforcement in both tension and compression zones. Design steps are provided for both section types, including calculating loads, moments, reinforcement areas, and shear reinforcement. Formulas and assumptions used in the design process are also outlined. The goal is for students to learn to properly design reinforced concrete beam sections based on given structural loads and material properties.
A shear wall is a vertical structural element used to resist horizontal forces such as wind and seismic forces. Shear walls are generally used in high-rise buildings where the effects of wind and seismic forces are more significant. Shear walls are usually provided along both the length and width of buildings and act like vertically-oriented beams that carry earthquake loads downwards to the foundation. Common types of shear walls include reinforced concrete, concrete block, steel, plywood, and mid-ply shear walls. Shear walls must provide the necessary lateral strength to resist horizontal earthquake forces and lateral stiffness to prevent excessive side-sway of the structure.
This document summarizes a lecture on flat slab design and analysis. It discusses key topics such as:
1. Definitions of flat slabs and their components like column strips and middle strips.
2. Methods of analyzing flat slabs including numerical methods and manual methods like the method of substitutive beams.
3. Design considerations for flat slabs including steel distribution above columns, welded mesh reinforcement, loading schemes, and punching shear design.
4. Different types of shear reinforcement that can be used at column heads like links, cages, and bent-up bars.
Framed structures are building skeleton frameworks formed by columns and beams. There are two main types: in-situ reinforced concrete frames and prefabricated frames. Rectangular framed structures use columns and beams arranged at right angles to support floors, walls, and roofs. They are commonly used for multi-story buildings like offices, schools, and hospitals. Framed structures provide large open floor plans and are adaptable to different shapes. Earthquake-resistant features in framed structures include shear walls, moment-resisting frames, and braced structures which resist lateral forces during seismic activity.
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
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.
This report compares design codes for hollow block and ribbed slabs. It includes:
- A comparison of limitations between Egyptian, British, Euro and American codes on rib spacing, slab thickness, and other parameters.
- Solved examples for one-way and two-way slabs according to different codes, finding the Egyptian code most economical.
- Analysis of using one or two cross-ribs, determining one rib at midspan is sufficient.
- Different modeling methods for the slabs in structural analysis software, with minor differences in results.
- Case studies presented for one-way, cantilever, two-way hollow block slabs, and ribbed slabs using
This document discusses ductile detailing of reinforced concrete (RC) frames according to Indian standards. It explains that detailing involves translating the structural design into the final structure through reinforcement drawings. Good detailing ensures reinforcement and concrete interact efficiently. Key aspects of ductile detailing covered include requirements for beams, columns, and beam-column joints to improve ductility and seismic performance. Specific provisions are presented for longitudinal and shear reinforcement in beams and columns, as well as confining reinforcement and lap splices. The importance of cover and stirrup spacing is also discussed.
High Rise Building Structure Systems Types
Slide Contents :
INTRODUCTION
INTRODUCTION TO HIGH-RISE DESIGN
DEMANDS FOR HIGH RISE BUILDING
MATERIAL
TYPES OF SYSTEMS
CONSTRUCTIONAL DETAILS
ADVANTAGES AND DISADVANTAGES
1) The document discusses the analysis and design of a high rise building project submitted by Ishant Kukreja. It includes imposing wind and earthquake loads on the building and analyzing its structural behavior.
2) The structural elements like beams, columns, and shear walls are designed. Beam design, shear reinforcement, and column design results are presented.
3) Future prospects discussed include designing the structure for earthquake loads, designing a staircase, using a hybrid RCC and steel structure, and comparing cost. The project helps expand knowledge in high rise design and analysis considering important loads.
Waffle slabs are reinforced concrete slabs reinforced in two orthogonal directions, forming a ribbed plate. They are characterized by their total edge height, lightening block height, rib spacing, rib thickness, and compression layer thickness. Waffle slabs can adequately support distributed and point loads in two directions. Benefits include flexibility, light weight allowing longer spans, fast construction, slim depths, robustness, vibration control, thermal mass, and durability. Waffle slabs are constructed with ribs forming a grid pattern and solid fills at supports. Larger spans may use post-tensioning or joist construction. Proper design considers loads, materials, deformations, and tile installation compatibility.
Shoring is the construction of a temporary structure to support an unsafe or unstable structure. There are three main types of shoring: raking shores, flying shores, and dead shores. Raking shores use inclined members called rakers to provide lateral support to walls. Flying shores provide temporary support between party walls when an intermediate building is demolished. Dead shores provide vertical support to walls and structures when the lower part of a wall is removed, such as to add an opening.
Stone masonry uses stones bonded together with mortar to construct various building components such as walls, columns, foundations, arches and lintels. Stones are selected based on availability, ease of working, appearance, strength, polishing characteristics and economy. There are two main types of stone masonry - rubble masonry which uses roughly dressed stones with wider joints, and ashlar masonry which uses accurately dressed stones with fine, uniform joints. Rubble masonry includes uncoursed, coursed, random, dry and polygonal styles based on stone arrangement. Ashlar masonry has fine, rough, rock-faced, block and chamfered styles based on stone dressing. Stone
The document discusses structural steel, including its composition, properties, types, and applications in construction. It describes how steel is made from iron with added elements, and its varying properties based on carbon content. The types discussed are mild steel, medium carbon steel, and high carbon steel. Common structural steel applications mentioned include beams, columns, trusses, and framing for buildings like airports and stadiums.
This document provides an overview of different types of retaining walls, including gravity, cantilever, counterfort, sheet pile, and diaphragm walls. It discusses the key components and design considerations for gravity and cantilever retaining walls. Gravity walls rely on their own weight for stability, while cantilever walls consist of a vertical stem with a heel and toe slab acting as a cantilever beam. The document also covers lateral earth pressures, drainage of retaining walls, uses of sheet pile walls, and construction methods for diaphragm walls.
Waffle slab or ribbed slab is a structural component with a flat top surface and grid-like bottom surface containing perpendicular ribs. It has two-directional reinforcement and is used for large spans to avoid many interior columns. The waffle shape is formed by placing pods on the formwork before pouring concrete, leaving ribs containing reinforcement. Waffle slabs provide stiff, lightweight structures suitable for areas requiring low deflection and vibration control like airports and hospitals.
1) High rise buildings are becoming more common due to scarcity of land and demand for space. They are defined differently but generally refer to buildings over 15 meters tall.
2) Foundations for high rise buildings include shallow foundations like spread footings and mat foundations, and deep foundations like piles. Piles transfer load through end bearing or friction along their length.
3) Structural systems for high rise buildings must resist both gravity and lateral loads. Interior systems include rigid frames and shear walls. Exterior systems such as tube and diagrid systems resist loads along the building perimeter.
This document provides details on the design and construction of flat slab structures. It discusses the benefits of flat slabs such as flexibility in layout, reduced building height and faster construction. Key considerations for design include wall and column placement, structural layout optimization, deflection checks, crack control and punching shear. Analysis involves dividing the slab into strips and determining moment and shear distributions. Reinforcement is arranged in two directions and detailing includes reinforcement lapping and service penetrations.
The document discusses tube frame structures for tall buildings. Tube frame structures were introduced by Fazlur Khan and involve a hollow cantilever tube perpendicular to the ground. They allow for buildings over 40 stories tall with configurations including framed tubes, braced tubes, tube-in-tube, and bundled tubes. Tube frame structures provide benefits like increased structural rigidity and regular column placement but also have disadvantages like reduced window size and occurrence of shear lag effects.
This document discusses composite construction and cambering of steel beams. It provides information on:
1) The composite construction process including use of composite metal decking, shear connectors, and concrete pouring to create a composite floor system that is stronger and stiffer than steel alone.
2) The advantages of composite construction such as reduced steel needs, lighter weight, and increased spans.
3) The cambering process of inducing a slight curvature in steel beams to compensate for deflection under loads in order to achieve a level floor slab.
4) When cambering is appropriate such as for filler beams, and when it is not such as for moment connected beams. Alternative methods to cambering like
This document discusses the analysis of singly and doubly reinforced concrete beam sections. It provides definitions and design approaches for singly reinforced, doubly reinforced, and flanged beam sections. The key steps in the design process are outlined, including calculating loads and moments, checking for section type, sizing tension and compression reinforcement, and designing shear reinforcement. Design examples are provided for a singly reinforced and a doubly reinforced concrete beam according to BS 8110 design code standards.
This document discusses the analysis of singly and doubly reinforced concrete beam sections. It begins by defining singly reinforced sections as having tension reinforcement only, while doubly reinforced sections have reinforcement in both tension and compression zones. Design steps are provided for both section types, including calculating loads, moments, reinforcement areas, and shear reinforcement. Formulas and assumptions used in the design process are also outlined. The goal is for students to learn to properly design reinforced concrete beam sections based on given structural loads and material properties.
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 discusses the design of flat slab structures. It begins by defining a flat slab as a type of slab supported directly on columns without beams. It then provides details on the types of flat slabs, their common uses in buildings, and benefits such as flexibility in layout and reduced construction time. The document goes on to discuss key design considerations for flat slabs including thickness, drops, column heads, and methods of analysis. It focuses on the direct design method and provides limitations for its use, such as rectangular panel shapes and span length ratios.
The document outlines the sequence of activities involved in building a house. It begins with designing the house and obtaining financing, which takes 3 months. Next, the foundation is laid after the design is completed, taking 2 months. Various construction activities like framing, electrical work, plumbing etc are then carried out concurrently or sequentially as needed, with an overall construction period of 6 months. The document thus provides a overview of the key steps and their timeline for a house building project.
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.
The document discusses flat slab construction and design. It begins by defining a flat slab as a reinforced concrete slab without beams that transfers loads directly to supporting columns. It describes various types of flat slabs including simple flat slabs, those with drop panels or column heads, or both. The document outlines design considerations for flat slabs including analyzing column and middle strips, estimating depth, and calculating moments and shear. It also discusses advantages such as reduced height and construction time. In summary, the document provides information on flat slab types, design methodology, and benefits compared to other construction methods.
The document provides information on structural design and analysis. It discusses structural planning, wind load analysis, frame analysis using software, beam, column, slab, footing and retaining wall design. Key steps covered include determining loads, checking member capacities, calculating reinforcement and developing design details. The goal is to ensure the structural safety and stability of the building under various loads like gravity, wind, seismic, etc.
This document discusses various reinforced concrete floor systems for medium and long span structures. It describes objectives like minimizing floor-to-floor height, maximizing column-free spaces, minimizing weight and construction time. Systems covered include flat slabs with drop panels, flat plates, ribbed slabs, waffle slabs, and band beams & slabs. Each system is summarized briefly, including advantages like simple formwork, long spans, and material savings, as well as disadvantages like depth controlling fire rating and need for specialized formwork. Reinforcement details to improve slab punching shear resistance are also mentioned.
The document presents the design of a multi-level car parking structure with 4 floors above ground in Thirunelveli, India. The objectives are to analyze and design the structure, estimate construction costs, and provide safe, accessible parking. The methodology includes planning, analysis, design, detailing, estimation. The building is a concrete frame structure with a conventional car parking layout accessed by a helical ramp and stairs/lift. Structural analysis was conducted manually and using STADD Pro software. Key elements like slabs, beams, columns, footings, staircase, and ramp were designed according to Indian codes and standards.
This document provides an analysis and design of the structural elements for a multi-storey residential building, including slabs, columns, shear walls, and foundations. It discusses the objectives, general approach, types of buildings and concrete mixtures used. The structural elements are then analyzed and designed according to the given specifications and loadings, with reinforcement details provided for slabs, columns, shear walls, and pile caps.
Design of flat plate slab and its Punching Shear Reinf.MD.MAHBUB UL ALAM
Ā
This document provides design considerations and an example problem for designing a flat plate slab using the Direct Design Method (DDM). It discusses slab thickness, load calculations, moment distribution, and reinforcement design for a sample four-story building with 16'x20' panels supported by 12" square columns. The design of panel S-4 is shown in detail, calculating loads, moments, and reinforcement requirements for the column and middle strips in both the long and short directions.
Analysis and Design of G+3 building with flat slab using STAAD PRO V8i M F-1....ManoharManu993491
Ā
This document describes the analysis and design of a residential building with four stories using flat slab construction in STAAD Pro software. It includes modeling the building with drop panels and column heads, applying dead, live and roof loads, performing analysis to obtain deflections, bending moments and pressures, and designing the concrete columns and slab according to IS 456 code. The results show maximum bending moments in beams of 210 kN-m, and designs meet code requirements for shear, bending and deflections.
This document discusses the design of two-way floor slab systems. It compares the behavior of one-way and two-way slabs, describing how two-way slabs carry load in two directions versus one direction for one-way slabs. Different two-way slab systems like flat plates, waffle slabs, and ribbed slabs are described. Methods for analyzing two-way slabs include direct design, equivalent frame, elastic, plastic, and nonlinear analysis. Design considerations like minimum slab thickness are discussed along with examples calculating thickness.
This document discusses the design of a 12-story residential building in Abu Dhabi. It covers the structural elements that will be designed, including flat slabs, columns, shear walls, and pile foundations. The structural system and design loads are defined. Methods for analyzing and designing the different elements are presented, including calculating reactions, moments, and reinforcement. Reinforced concrete is determined to be an economical and environmentally friendly solution for the multi-story building.
The document provides details about an internship at Srushti Engineers & Valuers company. It includes information about the company profile such as its founder, location, and years in operation. It also describes several completed construction projects the company has worked on. The main focus of the internship is a residential building project including plans, cost estimates, and construction methodology for activities like excavation, plinth beams, brick masonry, RCC slabs, plastering and flooring. The intern aims to gain practical experience and apply their theoretical knowledge through this project.
This document provides details on the design of a rectangular water tank resting on ground. It discusses the analysis done to determine bending moments and tensile forces in the walls. It then shows the step-by-step design of the walls and base slab of a 5m x 4m rectangular tank with 3m depth, reinforced with Fe415 steel bars in M20 concrete. Reinforcement details are calculated and sketched to resist vertical and horizontal bending moments at the wall corners and edges.
Formwork is a temporary structure used to hold wet concrete in desired shape until it hardens. It is classified based on size, material, and operation. Requirements include strength, water resistance, smooth surfaces. Common formwork includes foundations, walls, columns, slabs, beams, stairs using timber, steel, aluminum, plastic. Removal timing depends on concrete type. Cost is 30-60% of concrete cost. Advanced systems like REVOLA and LOGICA use steel/plywood/polymer facing for crane-lifted walls and columns, withstanding high pressures.
This document provides information on formwork used for constructing concrete structures. It discusses the different types of formwork including wooden, plywood, steel and combined forms. It also describes requirements for proper formwork like being waterproof and strong enough to support loads. Common formwork systems are described for columns, beams, slabs, stairs and walls. Standards for stripping formwork from concrete structures are also outlined according to the Indian Standard code.
The document discusses the design of reinforced concrete beams. It defines key terms related to beam design such as effective depth, clear cover, and balanced/unbalanced sections. It also describes the process for designing beams, which involves calculating design constants, assuming beam dimensions, determining loads and bending moments, calculating steel reinforcement requirements, checking for shear and deflection, and developing a design summary. The goal of the design process is to select a beam section that will safely and satisfactorily carry loads over the structure's lifetime.
Folded plate structures are assemblies of flat plates connected along their edges that form a rigid structural system capable of carrying loads without internal beams. Engineer Eudene Freyssinet performed the first roof with a folded structure in 1923. Folded structures mimic systems in nature like leaves and insect wings. Their structural behavior depends on factors like the folding pattern and connection of planes. Folded structures have applications as roofs, walls, floors, and foundations and provide advantages like lightness and long spans but also challenges like complex formwork. Examples include the US Air Force Academy Chapel and structures in Bangladesh.
Yield line theory is an analysis approach for determining the ultimate load capacity of reinforced concrete slabs. It was pioneered in the 1940s and is closely related to plastic collapse analysis of steel frames. It assumes ductile behavior where yield lines form that allow further rotation without additional moment. Yield line analysis is allowed by some codes if the ratio of crack spacing to depth is low. Advantages are it is simpler than elastic analysis and gives ultimate capacity rather than just yield load, while disadvantages are it requires understanding likely failure mechanisms and may allow dangerous designs without further checking.
Reinforced cement concrete (RCC) is a composite material made of cement concrete reinforced with steel bars. Some key points:
- FranƧois Coignet built the first reinforced concrete structure, a four story house in Paris in 1853.
- RCC is used in the construction of columns, beams, footings, slabs, dams, water tanks, tunnels, bridges, walls and towers due to its high strength and durability.
- The steel reinforcement provides tensile strength, while the concrete primarily resists compressive forces and protects the steel from corrosion. Together they form a very strong, stable structural material.
Space frames are rigid, lightweight structures constructed from interlocking struts arranged in geometric patterns. They can span large areas with few interior supports due to their inherent rigidity from triangular formations that transmit loads as tension and compression. Folded plate structures are assemblies of rigidly connected flat plates that can carry loads without interior beams. They were first used in 1923 for an aircraft hangar roof in Paris and take inspiration from structures in nature like tree leaves. Cable structures have cables as their primary load-bearing elements and are often used in bridges and roofs to transmit loads between supports.
Fibre reinforced concrete is a composite material consisting of cement, mortar or concrete and discrete, uniformly dispersed fibres that can improve the flexural, impact and fatigue strength of concrete. Common fibres used include steel, polypropylene, nylon, glass and carbon fibres. The fibre geometry, content, orientation and distribution affect the composite material properties. Self-compacting concrete is a highly flowable mixture that does not require vibration for placing and consolidation due to its high deformability and low yield value. It provides benefits over conventional concrete such as faster construction, better surface finish and reduced noise levels. The mix design of SCC focuses on optimizing the powder content, chemical admixtures and viscosity.
Circular slabs are used for roofs that are circular in plan, floors of circular tanks or towers, and roofs over pump houses or traffic control posts. Bending occurs in two perpendicular directions for circular slabs. Reinforcement is provided as a mesh with equal area in both directions, sized for the larger of the radial or circumferential moments. Near edges, radial and circumferential reinforcement may be needed if edge stresses are significant or if the edge is fixed. Circular slabs are commonly used in water tanks, where they deflect into a saucer shape under uniform loads and develop tensile and compressive stresses radially and circumferentially.
The document discusses the design of beams subjected to combined bending, shear, and torsional moments according to Indian code IS 456. It defines the two types of torsional moments, provides examples of structural elements that experience torsion, and explains the code's approach which involves determining equivalent shear and bending moments. The design procedure involves selecting a critical section and determining longitudinal and transverse reinforcement based on the equivalent internal forces. Numerical examples are also provided to illustrate the design process.
- Deep beams are defined as beams with a shear span to depth ratio of less than 2. They behave differently than ordinary beams due to two-dimensional loading and non-linear stress distributions.
- Deep beams transfer significant load through compression forces between the load and supports. Shear deformations are more prominent.
- Design of deep beams requires considering two-dimensional effects, non-linear stress distributions, and large shear deformations. Procedures include checking minimum thickness, designing for flexure and shear, and detailing reinforcement.
The document discusses different types of slabs used in structures. Slabs can be one-way or two-way, with one-way slabs primarily deflecting in one direction and two-way slabs supported by columns allowing deflection in two directions. Common slab types include simply supported, cantilever, fixed, overhanging, and continuous. Slabs require formwork, reinforcement including straight bars and cranked bars near supports, and concrete casting and curing.
Columns are structural elements that transmit loads in compression from beams and slabs above to other elements below. Columns can experience both axial compression and bending loads. Biaxial bending occurs when a column experiences simultaneous bending about both principal axes, such as in corner columns of buildings. The biaxial bending method permits analysis of rectangular columns under these conditions. The document provides details on analyzing a sample reinforced concrete column for adequacy using the reciprocal load method to check that factored loads do not exceed design capacity. Diagrams are presented showing interaction surfaces and stress distributions for concentrically and eccentrically loaded columns.
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 discusses the design of columns subjected to axial compression. It covers various buckling failure modes including flexural, local, and torsional buckling. It provides definitions of critical load and slenderness ratio, which are important parameters for column design. Design approaches are discussed including selecting a trial section based on slenderness ratio, calculating the design compressive stress, and checking if the design strength exceeds the factored load. Details are also provided on built-up column design using lacing, battens, and back-to-back members.
Calulation of deflection and crack width according to is 456 2000Vikas Mehta
Ā
This document discusses the calculation of crack width in reinforced concrete flexural members. It provides information on:
1) Crack width is calculated to satisfy serviceability limits and is only relevant for Type 3 pre-stressed concrete members that crack under service loads.
2) Crack width depends on factors like amount of pre-stress, tensile stress in bars, concrete cover thickness, bar diameter and spacing, member depth and location of neutral axis, bond strength, and concrete tensile strength.
3) The method of calculation involves determining the shortest distance from the surface to a bar and using equations involving member depth, neutral axis depth, average strain at the surface level. Permissible crack widths are specified depending on exposure
- 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.
Foundations can be broadly classified as shallow or deep. Shallow foundations include spread footings, combined footings, strap footings, and mat/raft foundations. Deep foundations transfer load to deeper soils and include pile foundations, pier foundations, and caissons/well foundations. Under-reamed pile foundations are recommended for expansive soils like black cotton soil as they anchor the structure below the moisture fluctuation zone. The piles are bored, under-reamed at the base, reinforced, and poured with concrete to provide a stable foundation.
Footings are the lower part of a building's foundation constructed below ground level. They transfer the building's live and dead loads to the soil over a large area to prevent movement of the soil or building. Footings must resist settlement and lateral loads. Their size depends on the allowable bearing capacity of the soil, total load on the footing, and column dimensions. Shear failure can occur at the footing-column connection or within the footing itself. Combined or strap footings are used to distribute loads across property lines or between closely spaced columns.
Deep beams are structural elements where a significant portion of the load is carried to the supports by compression forces combining the load and reaction. As a result, the strain distribution is nonlinear and shear deformations are significant compared to pure flexure. Examples include floor slabs under horizontal loads, short span beams carrying heavy loads, and transfer girders. The behavior of deep beams is two-dimensional rather than one-dimensional, and plane sections may not remain plane. Analysis requires a two-dimensional stress approach.
Definition Where this system can be used
Features of the Grid Slab
Decorative grid slabs in historical structures
Types of Grid Slab
Comparison: Long Span Structures
Construction
Technique
Formwork Required
Reinforcements Details
Modification in Grid Slab for Utility
Services Provided in Grid Slab
Benefits
Iconic Landmarks using Grid Slabs
The document defines different types of structural footings used to support columns, walls, and transmit loads to the soil. It discusses isolated, combined, cantilever, continuous, raft, and pile cap footings. It also covers footing design considerations like allowable bearing capacity, shear strength, bending moment, and reinforcement requirements. The document provides formulas and steps for calculating footing size, reinforcement, and checking design requirements.
Cricket management system ptoject report.pdfKamal Acharya
Ā
The aim of this project is to provide the complete information of the National and
International statistics. The information is available country wise and player wise. By
entering the data of eachmatch, we can get all type of reports instantly, which will be
useful to call back history of each player. Also the team performance in each match can
be obtained. We can get a report on number of matches, wins and lost.
An In-Depth Exploration of Natural Language Processing: Evolution, Applicatio...DharmaBanothu
Ā
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 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.
A high-Speed Communication System is based on the Design of a Bi-NoC Router, ...DharmaBanothu
Ā
The Network on Chip (NoC) has emerged as an effective
solution for intercommunication infrastructure within System on
Chip (SoC) designs, overcoming the limitations of traditional
methods that face significant bottlenecks. However, the complexity
of NoC design presents numerous challenges related to
performance metrics such as scalability, latency, power
consumption, and signal integrity. This project addresses the
issues within the router's memory unit and proposes an enhanced
memory structure. To achieve efficient data transfer, FIFO buffers
are implemented in distributed RAM and virtual channels for
FPGA-based NoC. The project introduces advanced FIFO-based
memory units within the NoC router, assessing their performance
in a Bi-directional NoC (Bi-NoC) configuration. The primary
objective is to reduce the router's workload while enhancing the
FIFO internal structure. To further improve data transfer speed,
a Bi-NoC with a self-configurable intercommunication channel is
suggested. Simulation and synthesis results demonstrate
guaranteed throughput, predictable latency, and equitable
network access, showing significant improvement over previous
designs
3. What is a flat slab?
A reinforced concrete slab supported directly by concrete columns
without the use of beams
4.
5. Uses of column heads :
ā¢ increase shear strength of slab
ā¢ reduce the moment in the slab by reducing the clear or
effective span
Flat slab with column head
6. Uses of drop panels :
ā¢ increase shear strength of slab
ā¢ increase negative moment capacity of slab
ā¢ stiffen the slab and hence reduce deflection
7. ā¢ Flexibility in room layout
ā¢ Saving in building height
ā¢ Shorter construction time
ā¢ Ease of installation of M&E services
ā¢ Prefabricated welded mesh
ā¢ Buildable score
8. Benefits . . .
ā¢ allows Architect to introduce partition walls anywhere
required
ā¢ allows owner to change the size of room layout
ā¢ allows choice of omitting false ceiling and finish soffit of
slab with skim coating
Benefits . . .
9. Benefits . . .
ā¢ Lower storey height will reduce building weight due to lower
partitions and cladding to faƧade
ā¢ approx. saves 10% in vertical members
ā¢ reduce foundation load
Beam
3.4m 2.8m
Slab
3.2m2.8m
10. Benefits . . .
flat plate design will facilitate the
use of big table formwork to
increase productivity
Benefits . . .
11. Benefits . . .
Living Roo m
Yard
30 Shower
75
26
0Kitchen 30 30
Toilet
Balcony
30
155
Flat Plate Slab
Single Level Ceiling
Simplified the table formwork needed
12. Benefits . . .
ā¢ all M & E services can be mounted directly on the
underside of the slab instead of bending them to avoid
the beams
ā¢ avoids hacking through beams
13. Benefits . . .
ā¢ Prefabricated in
standard sizes
ā¢ Minimised
installation time
ā¢ Better quality
control
14. Benefits . . .
ā¢ allows standardized structural members and
prefabricated sections to be integrated into the design
for ease of construction
ā¢ this process will make the structure more buildable,
reduce the number of site workers and increase the
productivity at site
ā¢ more tendency to achieve a higher Buildable score
15. Design Considerations. . . .
ā¢ Locate position of wall to maximise the structural
stiffness for lateral loads
ā¢ Facilitates the rigidity to be located to the centre of
building
Typical floor plan of Compass the Elizabeth
16. Design Considerations. . . .
ā¢ the sizes of vertical and structural structural members can
be optimised to keep the volume of concrete for the entire
superstructure inclusive of walls and lift cores to be in the
region of 0.4 to 0.5 m3 per square metre
ā¢ this figure is considered to be economical and comparable
to an optimum design in conventional of beam and slab
systems
17. Design Considerations. . . .
ā¢ necessary to include checking of the slab deflection for all
load cases both for short and long term basis
ā¢ In general, under full service load, < L/250 or 40 mm
whichever is smaller
ā¢ Limit set to prevent unsightly occurrence of cracks on
non-structural walls and floor finishes
18. Design Considerations. . . .
ā¢ advisable to perform crack width calculations based on
spacing of reinforcement as detailed and the moment
envelope obtained from structural analysis
ā¢ good detailing of reinforcement will
ā restrict the crack width to within acceptable
tolerances as specified in the codes and
ā reduce future maintenance cost of the building
19. Design Considerations. . . .
ā¢ No opening should encroach upon a column head or drop
ā¢ Sufficientreinforcementmust be providedto take care of
stress concentration
20. Design Considerations. . . .
ā¢ always a critical consideration in flat plate design around the
columns
ā¢ instead of using thicker section, shear reinforcement in the form
of shear heads, shear studs or stirrup cages may be embedded in
the slab to enhance shear capacity at the edges of walls and
columns
22. Design Considerations. . . .
ā¢ critical for fast track project where removal of forms at
early strength is required
ā¢ possible to achieve 70% of specified concrete cube
strength within a day or two by using high strength
concrete
ā¢ alternatively use 2 sets of forms
23. Design Considerations. . . .
ā¢ buildings with flat plate design is generally less rigid
ā¢ lateral stiffness depends largely on the configuration of
lift core position, layout of walls and columns
ā¢ frame action is normally insufficient to resist lateral loads
in high rise buildings, it needs to act in tendam with walls
and lift cores to achieve the required stiffness
25. Design methodology .. .
ā¢ the finite element analysis
ā¢ the simplified method
ā¢ the equivalent frame method
26. Design methodology .. .
FINITE ELEMENT METHOD
ā¢ Based upon the division of complicated structures into smaller
and simpler pieces (elements) whose behaviour can be
formulated.
ā¢ E.g of software includes SAFE, ADAPT, etc
ā¢ results includes
ā moment and shear envelopes
ā contour of structural deformation
32. Design methodology .. .
SIMPLIFIED METHOD
Table 3.19 may be used provided
ā¢ Live load > 1.25 Dead load
ā¢ Live load (excluding partitions) > 5KN/m2
ā¢ there are at least 3 rows of panels of approximately
equal span in direction considered
ā¢ lateral stability is independent of slab column
connections
33. Design methodology .. ..
SIMPLIFIED METHOD
Table 3.19: BM and SF coefficients for flat slab or 3 or more equal spans
Outer Support Near centre
of 1st
span
First interior
span
Centre of
interior
span
Interior
span
Column Wall
Moment -0.04Fl* 0.086Fl 0.083Fl* -0.063Fl 0.071Fl -0.055Fl
Shear 0.45F 0.4F - 0.6F - 0.5F
Total
column
moments
0.04Fl - - 0.022Fl - 0.022Fl
* the design moments in the edge panel may have to be adjusted according to 3.7.4.3
F is the total design ultimate load on the strip of slab between adjacent columns considered
(1.4gk + 1.6 qk)
l is the effective span
34. Design methodology .. .
EQUIVALENT FRAME METHOD
ā¢ most commonly used method
ā¢ the flat slab structure is divided longitudinally and
transversely into frames consisting of columns
and strips of slabs with :
ā stiffness of members based on concrete alone
ā for vertical loading, full width of the slab is used to
evaluate stiffness
ā effect of drop panel may be neglected if dimension <
lx/3
35. Design methodology .. .
EQUIVALENT FRAME METHOD
Plan of floor slab Step 1 : define line of support
in X & Y directions
36. Design methodology .. .
EQUIVALENT FRAME METHOD
9 10 10 9.2 0.8
DESIGN STRIP IN PROTOTYPE
9 10 10.6 10.5 0.8
STRAIGHTENED DESIGN STRIP
DESIGN STRIP IN ELEVATION
Step 2 : define design strips in
X & Y directions
37. Analysis of flat slab..
COLUMN HEAD
lho
lh max
lc
dh
lho
lh max
lc
dh
Effective dimension of a head , lh (mm) = lesser of lho or lh max
where lho = actual dimension, lh max = lc +2(dh-40)
(i) lh = lh, max (ii) lh = lho
38. Analysis of flat slab..
COLUMN HEAD
lho
lh max
lc
dh
(iv) lh = lho
lho
lh max
lc
dh
40
(iii) lh = lh,max
For circular column or column head,
effective diameter , hc = 4 x area/ļÆ < 0.25 lx
39. Analysis of flat slab..
DIVISION OF PANELS
lx/4
Columnstrip
lx/4
lx/4
The panels are divided into ācolumn stripsā and middle stripsā
in both direction.
(a) Slab Without Drops
Column strip
middle strip (ly-lx/2)
middle
strip
lx/4
lx(shorterspan)
ly (longer span)
40. Analysis of flat slab..
lx
Drop
middle strip (ly-drop size)
lx/4
middle
strip
Column strip
= drop size
ly (longer span)
note : ignore drop if dimension is less than lx/3
Drop
(b) Slab With Drops
41. Analysis of flat slab..
MOMENT DIVISION
Apportionment between column
and middle strip expressed as %
of the total negative design
moment
Column strip Middle strip
Negative 75% 25%
Positive 55% 45%
ā¢ Note : For slab with drops where the width of the middle strip
exceeds L/2, the distribution of moment in the middle strip should
be increased in proportion to its increased width and the moment
resisted by the column strip should be adjusted accordingly.
42. Analysis of flat slab..
MOMENT DIVISION - EXAMPLE
6000 6000 6000 6000 6000
5000
Layout of building
7000
5000
A floor slab in a building where stability is provided by shear walls
in one direction (N-S). The slab is without drops and is supported
internally and on the external long sides by square columns . The
imposed loading on the floor is 5 KN/m2 and an allowance of
2.5KN/m2 for finishes, etc. fcu = 40 KN/m2, fy = 460KN/m2
43. Analysis of flat slab..
MOMENT DIVISION - EXAMPLE
6000 60006000 6000
5000
7000
2500
1500
2750
4000
1250
3500 2500
3000 3000
3500 2500
Division of panels into strips in x and y direction
44. Analysis of flat slab..
3000 3000
3500 2500
MOMENT DIVISION - EXAMPLE
6000 6000
200 200
35 35
3500 2500
200 200
369
Column strip
exterior support
centre of 1st span
1st interior support
= 0.75*35 on 2.5m strip = 10.5Knm
= 0.55*200 on 2.5 strip = 44KNm
= 0.75*200 on 3m strip = 50KNm
centre of interior span = 0.55 *369 on 3m strip = 67.7KNm
Middle strip
exterior support
centre of 1st span
1st interior support
= 0.25*35 on 2.5m strip = 3.5KNm
= 0.45*200 on 2.5 strip = 36KNm
= 0.25*200 on 3m strip = 16.7KNm
centre of interior span = 0.45 *369 on 3m strip = 55.4KNm
45. Analysis of flat slab..
DESIGN FOR BENDING
INTERNAL PANELS
ā¢ columns and middle strips should be designed to
withstand design moments from analysis
46. Analysis of flat slab..
DESIGN FOR BENDING
EDGE PANELS
ā¢ apportionment of moment exactly the same as internal
columns
ā¢ max. design moment transferable between slab and
edge column by a column strip of breadth be is
< 0.5 design moment (EFM)
< 0.7 design moment (FEM)
Otherwise structural arrangements shall be changed.
Mt, max = 0.15 be d2 fcu
48. Analysis of flat slab..
DEFLECTION
(i) use normal span/effective depth ratio if drop width >1/3
span each way; otherwise
(ii) to apply 0.9 modification factor for flat slab, or
where drop panel width < L/3
1.0 otherwise
Span/depth ratio
Cantilever 7
Simply supported 20
Continuous 26
49. Holes in areas bounded by the column strips may be formed providing :
ā¢ greatest dimension < 0.4 span length and
ā¢ total positive and negative moments are redistributed between the
remaining structure to meet the changed conditions
Analysis of flat slab..
ly (longer span)
lx(shorterspan)
50. Analysis of flat slab..
Holes in areas common to two column strips may be formed providing :
ā¢ that their aggregate their length or width does not exceed one-tenth of
the width of the column strip;
ā¢ that the reduced sections are capable of resisting with the moments;
and
ā¢ that the perimeter for calculating the design shear stress is reduced if
appropriate
ly (longer span)
lx(shorterspan)
51. Analysis of flat slab..
ly (longer span)
lx(shorterspan)
Holes in areas common to the column strip and the middle strip may be
formed providing :
ā¢ that in aggregate their length or width does not exceed one-quarter of
the width of the column strip and
ā¢ that the reduced sections are capable of resisting the design moments
52. Analysis of flat slab..
For all other cases of openings, it should be framed on all
sides with beams to carry the loads to the columns.
Analysis of flat slab..
53. Detailing of flat slab .. .
F-mesh- A mesh formed by main wire with cross wire at a fixed
spacing of 800 mm
Main wire - hard drawn ribbed wire with diameter and spacing
as per design
Cross wire - hard drawn smooth wire as holding wire
H8-800mm c/c for main wire diameter > 10mm
H7-800mm c/c for main wire diameter of 10mm and
below
54. Detailing of flat slab .. .
Main Wire
F-Mesh 2
Holding Wire
Holding Wire
(800mm c/c)
Main Wire
F-Mesh 1
71. Thank you
Mr. VIKAS MEHTA
School of Mechanical and civil engineering
Shoolini University
Village Bajhol, Solan (H.P)
vikasmehta@shooliniuniversity.com
+91 9459268898