Basic principle of pile cap design the structural world. Depending on the code of a country, the critical section for checking punching shear in slabs is taken at 0. Shear design of beams and slabs design of columns detailing of members leading variable action and accompanying variable action. This part of bs 8110 gives recommendations for the structural use of concrete in.
This paper compares design provisions for punching shear at internal columns in the superseded british standard bs 8110, eurocode 2 ec2 and fib model code 2010 mc2010. Design of concrete structures part i general rules and rules for buildings. Aci 31805, cebfip mc 90, and bs 8110 97, represent different. As per slab dimensions, only bottom slab having depth d2 is effective for resisting punching. Design for punching shear should allow for the effects of moment transfer at the columnslab junction. Pdf the reinforced concrete flat slab is an economical and popular. The punching shear strength of the concrete is not sufficient. Sharedesign strength for bs 8110 the design strength of material for different cases is tabulated in the bs 8110 part 01 table 2. A total of 79 tested slabs without shear reinforcement were selected from literature to study the treatments by these methods. Discrepancies exist in the provisions for the design of reinforced concrete pile caps for shear strength between the two uk codes for structural concrete design, bs 8110 and bs 5400. Chapter documents the design output produced by 4 the programs.
The results of this exercise have also been used for recommending a revision to the clauses given in the eurocode dd env 199211. This paper compares design provisions for punching shear at internal columns in the superseded british standard bs8110, eurocode 2 ec2 and fib model code. This has not been particularly difficult, as the fundamental approach to the provision of punching shear reinforcement is the same in most design codes. Punching shear % steel structural engineering general.
Aug 30, 2010 rcc2000 spreadsheets for concrete design to bs 8110 and ec2 user guides for each spreadsheet in ms word format and acrobat. Designing for shear in slabs including punching shear. The design shear for beamcolumn joint depends upon the relative strength of beam and column at the joint. Punching shear strength of reinforced concrete slabs. Sep 03, 2011 design of reinforced concrete slabs 103 calculated punching shear stress at perimeter ui shear force per unit width for bending about xaxis shear force per unit width for bending about yaxis maximum crack width mm depth of neutral axis from compression face distance from edge in ldirection to start of a yield line. Punching shear analysis of reinforced concrete flat plates osman m. Manual for the design of reinforced concrete building. According to muttoni and schwartz,12 the width of the critical crack can. The punching shear strength predicted by the fuzzybased model is compared with those predicted by current punching shear strength models widely used in the design practice, such as aci 31805. Your participation and feedback are deeply appreciated, thank you very much indeed.
Bending moment coefficient for simply supported twoway slab ref. The ancon design program allows reductions to be applied to the critical shear perimeter as appropriate. Concentric punching shear strength of reinforced concrete flat plates fariborz moeinaddini submitted in total fulfilment of the requirement of the degree of master of engineering june 2012 centre for sustainable infrastructure, faculty of engineering and industrial science swinburne university of technology, melbourne, australia. Design reinforcement if reasonable, if not, change form of structure. Punching shear strength as function of slab rotation the opening of the critical shear crack reduces the strength of the inclined concrete compression strut carrying shear and eventually leads to the punching shear failure. Footing thickness is adequate for resisting punching shear once vu vc. Shear design capacity deep beam 27% ok ok consulting e n g i n e e r s 4 member design reinforced concrete beam bs8110 v2015. The program allows analysis to bs en 1992 eurocode 2. Punching shear design the design to prevent punching shear failure proceeds as.
The shear capacity of the slab is checked against the design shear forces at the critical shear perimeter. Structural engineers and uses the format of the green book manualfor bs 8110. Empirical methods of designing against punching shear failure are given in 3. The punching shear strength predicted by the fuzzybased model is compared with those predicted by current punching shear strength models widely used in the design. Part 1 1985, eurocode 2 pren 199211 and aci 31802 on pad foundations, with particular emphasis on punching shear was first carried out. Pdf punching shear analysis of reinforced concrete flat. Chapter 2 provides detailed descriptions of thedeign prerequisites used for bs 8110 1997. We strongly recommend the shear stud design is verified against an alternate standard such as bs en 199211 eurocode 2 or bs 8110. Reinforced concrete design to bs8110 structural design 1 lesson 5 1 lesson 5. Bs 8110 details how deflections and the accompanying crack widths may be. Member design reinforced concrete beam bs8110 v2015. Chapter 3 provides detailed descriptions of the code specific process used for 8110 1997. These discrepancies have arisen in the historical development of the codes, and the implication is that one. To check the punching shear, the following are the design considerations.
Therefore the software is based on a research paper. Pdf punching shear resistance of normal and high strength. Ultimate moment and shear coefficients in continuous one way slab ref. Form of shear reinforcement to be area of shear reinforcement provided to be provided nmm2 less than 0. It was found that, only euro code 2 pren 199211 outlines briefly the issue of pad foundations on rock.
The tension bars must be anchored by bending them up the sides of the pile cap. Punching shear in safe 16 general discussion structural. Footings example 1design of a square spread footing of a sevenstory building design and detail a typical square spread footing of a six bay by five bay sevenstory building, founded on stiff soil, supporting a 24 in. Punching shear in pad foundations on rock techylib. Shearfix punching shear reinforcement ancon australia.
Punching shear punching shear symbols ui ith perimeter. Comparison of punching shear requirements in bs 8110, ec2 and. Comparison of punching shear requirements in bs 8110, ec2. Reinforced concrete design to bs8110 structural design 1 lesson 5 6 4.
The first stage of the design is finding the bending moment of the slab panels. As with the green book the scope of the manualcovers the majority of concrete building structures and has now been extended to cover slender columns and prestressed concrete. Shearfix designed to bs en 1992 can also be applied to structures designed to bs 8110. Mc2010 is based on the critical shear crack theory proposed by muttoni, which relates shear resistance to the width of the socalled critical shear crack which depends. Pdf punching shear analysis of reinforced concrete flat plates. Rcc2000 spreadsheets for concrete design to bs 8110 and ec2 user guides for each spreadsheet in ms word format and acrobat. Min and max reinforcement as a percentage of the gross csa. Footings example 1 design of a square spread footing of a. It can check a userdefined base design or autodesign an optimum solution to suit user and code criteria.
For structures, the lateral stability of which do not rely on the frame action between the slab and columns and in which adjacent spans do not differ in length by more than 25%, the design punching shear may be obtained by enhancing v ed by 1. Design of shear reinforcement against punching the. Sep 25, 2017 the attached picture is a snapshot of the example bs 8110 97 rcpn001. Changing the form of structure includes deepening the slab, making the column. Sachpazis date 18012014 chkd by date appd by 1 flat slab design to bs8110. Sachpazis date 18012014 chkd by date appd by 2 characteristic strength of concrete. Depending on the boundary condition and the properties of the slabs, methods of finding bending moment is expressed in the bs 8110 part 01 as follows. Its the effect of the bending moments on a particular critical section that adds a considerable amount of punching shear stress which is hard to grasp. Safe checks punching shear twice, once for column punching through the drop panel, then once for droppanel punching through. If not, check if the amount of reinforcement is reasonable. The bsi committee b5252 csb39 as it was then called had expressed concern about the present design method given in bs 8110.
Member design reinforced concrete two way spanning. The attached picture is a snapshot of the example bs 8110 97 rcpn001. Usually in malaysia, the design of structures will be guided by using british standard, bs 8110. Punching shear twoway shear beam shear oneway shear minimum reinforcement in the following, the values in square brackets are defaults of the program. Punching shear analysis of reinforced concrete flat plates. As discussed in chapter 4, the critical section for punching shear is located at distance d 2 from column faces and usually takes the shape of the column. Reinforced concrete design to bs8110 structural design 1. Although used for most civil engineering and building structures, bridges. A summary of essential differences between ec2 and bs8110. Overview stud rails have been used extensively and have been verified by testing in canada and mainland europe.
The bottom of the footing is ft below finished grade. This paper examines the design methods for providing resistance against punching shear, generally concerning the strength requirement for transfer of the load from a flat slab to the supporting column or from a column to its base. Apr 28, 2020 alternatively, a spreadsheet could be used e. Slab punching shear check in the key features and terminology manual. In addition to as3600, the ancon program enables design of a shearfix system to bs 8110 and bs en 1992, eurocode 2. Critical section for punching shear is at a distance of 1. Comparison of partial factors for loading design situations bs 8110 ec2 with one variable action live load 1. Design of foundations universiti teknologi malaysia. Punching shear with a punch dennis mercados structural.
Concrete bs 8110 1997, which is referred to as bs in this manual. This easytouse program allows the optimum design to be determined and generates a printable calculation sheet, a dxf file and a parts list of the specified layout. Punching strength with shear reinforcement firstly, one has to check if the design shear force v d is smaller than the maximum punching. Punching shear does notuse the variable strut inclination method and is similar to bs 8110 methods the basic control perimeter is set at 2d from the loaded area. Hi i am not familiar with bs 8110, but basic physics of the phenomenon is the same. Refer attached pdf file as per bs 8110, for calculating punching shear capacity we have to consider % tensile reinforcement. The ancon design program simplifies the specification and ordering of a shearfix system. Bs 8110 design shear construction solutions a division of arcelormittal kent wire limited table 3 form and area of shear reinforcements in beams value of. The tension reinforcement should be provided with full anchorage in accordance with section 3. Rcc2000 spreadsheets for concrete design to bs 8110 and ec2. Design for punching shear concrete structures eurocode.
Mc2010 is based on the critical shear crack theory proposed by muttoni, which relates shear resistance to the width of the socalled critical shear crack which depends on slab rotation. Nov 05, 2019 slab design is comparatively easy when compared with the design of other elements. Most design codes base their verifications on a critical section, with the punching shear strength of slabs with orand without shear reinforcement defined as a function of the concrete compressive strength and often of the reinforcement ratio. Design of reinforced concrete slabs 103 calculated punching shear stress at perimeter ui shear force per unit width for bending about xaxis shear force per unit width for bending about yaxis maximum crack width mm depth of neutral axis from compression face distance from edge in ldirection to start of a yield line.
If it were only bs like the equations shown above, the additional punching shear brought about by the unbalanced bending moment in the columns of a flat slab or flat. The procedure for determining the punching shear requirements is shown in figure 4. Cads rc slab designer provides fast, automatic rc design to bs 8110 for all typical bar arrangements, mesh and slab configurations and can be used standalone or as part of the cads integrated analysis, design and detailing solution. Code of practice for design and construction this part of bs 8110 gives recommendations for the structural use of concrete in buildings and structures, excluding bridges and structural concrete made with high alumina cement. Concentric punching shear strength of reinforced concrete. Member design reinforced concrete two way spanning slab bs8110 v2015.
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