If not, check if the amount of reinforcement is reasonable. This paper compares design provisions for punching shear at internal columns in the superseded british standard bs8110, eurocode 2 ec2 and fib model code 2010 mc2010. Punching shear design the design to prevent punching shear failure proceeds as. Pdf punching shear analysis of reinforced concrete flat. Reinforced concrete design to bs8110 structural design 1. Basic principle of pile cap design the structural world. Footing thickness is adequate for resisting punching shear once vu vc. Critical section for punching shear is at a distance.
Civil engineering spreadsheet collection 2018 update. The resulting stresses are verified along defined control perimeters around the loaded area. The shear capacity of the slab is checked against the design shear forces at the critical shear perimeter refer to as 36002009 for further details on determining the critical shear perimeter and if required. The tension reinforcement should be provided with full anchorage in accordance with section 3. The basic perimeter, u 1 is at 2d eff from the column. The punching shear is a failure mechanism in structural members like slabs and foundation by shear under the action of concentrated loads. A spreadsheet is a computer application that simulates a paper worksheet where becoming increasingly popular in solving engineering related problems. As per the british code bs 8110, the ultimate shear strength. I argued with a senior engineer about the punching shear check for shear wall. For slabs spanning in both directions published tables and charts should be used to find bending moment and shear per unit width of slab. 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. Changing the form of structure includes deepening the slab, making the column.
Problem with punching shear in shear wall points in slab. Punching shear twoway shear beam shear oneway shear minimum reinforcement in the following, the values in square brackets are defaults of the program. Aug 14, 2017 the concrete shear strength in oneway action is defined by the expression. Punching shear in pad foundations on rock techylib. In the indian code is 456, the punching shear strength is expressed as. Also in the case of design itself, the controlling case from a combination that contains earthquake will be the tension axial force not the compression please verify or disagree 3. Apr 28, 2020 the critical perimeter should be found iteratively, but it is generally acceptable to check at d and 2d. Apr 14, 2018 a spreadsheet is a computer application that simulates a paper worksheet where becoming increasingly popular in solving engineering related problems.
Punching shear analysis of reinforced concrete flat plates. Sep 06, 2016 since the slab is thin and there are no beams around the column, the column slab joint is prone to punching. Among the strong features of spreadsheets are their instinctive cellbased structure and easy to use capabilities. In uls design of the whole or any part of a structure each of the combinations of loading given in. Punchingshear faq safe computers and structures, inc. Shear design of beams and slabs design of columns detailing of members 7. Check stability against overturning in y direction total overturning moment. Form of shear reinforcement to be area of shear reinforcement provided to be provided nmm2 less than 0.
Total length of inner perimeter at edge of loaded area. Footings example 1 design of a square spread footing of a. Comparison of punching shear requirements in bs 8110, ec2 and mc2010 article in magazine of concrete research 6724. To check the punching shear, the following are the design considerations.
An assumption fundamental to the punchingshear check is that each column has one drop. 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 the shape of control perimeters have rounded corners bz by 2d 2d 2d 2d u1 u1 u 1 punching shear ec2. Dec 01, 2018 the tension reinforcement should be provided with full anchorage in accordance with section 3. Design the pile cap shown in the following figure with 12 in. 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. We strongly recommend the shear stud design is verified against an alternate standard, such as bs 8110 or bs en 1992, eurocode 2. For punching shear cases not affected by free edges or holes. It is assumed that the crack forms at about 45 degrees though it may vary between 2540 degrees and the failure is in the form of a tru. Required area for torsion shear per stirrups spacing according to eq. Since the slab is thin and there are no beams around the column, the column slab joint is prone to punching.
Column design as per bs8110 free download as powerpoint presentation. Punching shear analysis of reinforced concrete flat plates osman m. On the other hand, the punching shear strength depends of the column location on the footing, either interior, edge or corner, per the expression. Reinforced concrete design to bs8110 structural design 1 lesson 5 3 these basic ratios may be enhanced by provision and over provision of both tension and compression reinforcement as shown by the following tables. We are designing a foundation having two rcc slab as per bs 8110. 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. A finite element model may be created to analyse a complicated loading arrangement. Pdf punching shear analysis of reinforced concrete flat plates. In this sequence, safe traces the punching perimeters required for calculation. Punching shear % steel structural engineering general. In most cases, this reaction is the one from the column acting against the slab. This part of bs 8110 gives recommendations for the structural use of concrete in buildings and structures.
Sep 25, 2017 i argued with a senior engineer about the punching shear check for shear wall. 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. Pile supported foundation pile cap analysis and design. The action of concentrated loads is on a smaller area in the structural members. Pile supported foundation pile cap analysis and design based on a geotechnical study, a pile supported foundation is required to support a heavily loaded building column. The bottom of the footing is ft below finished grade. Punching shear resistance of various slabcolumn connections is calculated and compared with the corresponding. Punching shear resistance of various slabcolumn connections is calculated and compared with the corresponding predictions of different design specifications such as. Generally the punching shear strength values specified in different codes vary with concrete compressive strength f c or f ck and are usually expressed in terms of f n ck. Comparison of design methods for punching in bs8110, ec2 and mc2010. For the purposes of this part of bs 8110, the definitions given in bs 81101 apply, together with the following.
How to calculate punching shear in flat slab quora. The latter is based on the critical shear crack theory csct of muttoni which. View test prep 957267026punchingshearcalculation from cs 05 at university of tunku abdul rahman. It was found that, only euro code 2 pren 199211 outlines briefly the issue of pad foundations on rock. These discrepancies have arisen in the historical development of the codes, and the implication is that one. Comparison of punching shear requirements in bs 8110, ec2. 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. Sep 03, 2011 design of reinforced concrete slabs 107 b 1. The concrete shear strength in oneway action is defined by the expression. Design for punching shear concrete structures eurocode. Refer attached pdf file as per bs 8110, for calculating punching shear capacity we have to consider % tensile reinforcement. Punching strength with shear reinforcement firstly, one has to check if the design shear force v d is smaller than the maximum punching.
The procedure for determining the punching shear requirements is shown in figure 4. The tension bars must be anchored by bending them up the sides of the pile cap. The critical perimeter should be found iteratively, but it is generally acceptable to check at d and 2d. Part 1 1985, eurocode 2 pren 199211 and aci 31802 on pad foundations, with particular emphasis on punching shear was first carried out. A summary of essential differences between ec2 and bs8110. 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. Punching shear arises when a concentrated load is applied to a small area of a slab or, most commonly, the reaction of a column against a slab. Bs 8110 is a british standard for the design and construction of reinforced and prestressed concrete structures. Design of foundations universiti teknologi malaysia. An assumption fundamental to the punching shear check is that each column has one drop. 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. Safe checks punching shear twice, once for column punching through the drop panel, then once for droppanel punching through the slab. For the purposes of this part of bs 8110, the definitions given in bs 8110 1 apply, together with the following. Excel, for example, is a powerful spreadsheet with vba robust programming.
Although used for most civil engineering and building structures, bridges and waterretaining structures are covered by separate standards bs 5400 and bs 8007. Punching shear in safe 16 general discussion structural. The punching shear strength of the concrete is not sufficient. Design reinforcement if reasonable, if not, change form of structure. Comparison of punching shear requirements in bs 8110, ec2 and. Critical section for punching shear is at a distance of 1.
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