There are many reinforcement solutions available for increasing the punching shear capacity, such as bentup bars, stirrups, double headed shear. Punchingshear faq safe computers and structures, inc. The schock bole is a punching shear reinforcement consisting of doubleheaded studs and anchors with spacing bars to secure correct positioning. If users introduce additional punching shear reinforcement, the program verifies the behaviour of the reinforcement distribution in accordance with the selected code. This paper summarizes the results of 39 punching tests and compares the punching shear resistances obtained from the tests with the punching shear capacity of flat slabs without punching shear reinforcement according to aci 31814. Design software in etaconform version concrete plant precast. Jul, 2016 two way punching shear concept explained and flat plate example csa a23. As we all know, punching shear is a concentrated load causing shear stress on the section around the load and this load should be resisted by the structural member from where the concentrated load or the reaction is rested. Linkstudpsr is the new and definitive solution to the problem of punching shear in concrete structures, providing the ultimate in fast, simple and highly costeffective reinforcement. To determine the, the average soil pressure should be determined in the maximum loads stripes. Punching strength without shear reinforcement the punching shear strength of the concrete is not sufficient. But before going to these methods let us first consider the equation which gives us the punching shear strength of concrete slab without shear reinforcement be.
This paper summarizes the results of 39 punching tests and compares the punching shear resistances obtained from the tests with the punching shear capacity of flat slabs without punching shear reinforcement according to aci 31814 and eurocode 2 along with the german annex. The shear load from the slab is transferred through the. Aside from flexural checks, one of the most important points to consider in the design of the pile cap is the punching shear checks. The linkstudpsr system is the only punching shear reinforcement system. Punching shear how to design against punching shear. Punching shear reinforcement 7 punching shear resistance with doubleheaded anchors 8 design in the area c or 0. Punching shear analysis of reinforced concrete flat plates. Onscreen results and reports using the check option in the general data menu or the button from the toolbar, the following results can viewed onscreen or in a report. Due to the specially designed shape multi lowslip anchorage points in the concrete a component reinforced with hdbz up to 100 % more load capacity than a foundation without punching shear. Structural design of raft foundation pe civil exam. Armata punching reinforcement is the first icc approved doubleheaded shear rail system made from deformed reinforced bars. Although generally preceded by flexural failure, punching shear is a brittle failure mode and the risk of progressive collapse requires a higher safety class in structural design punching shear design.
The problem of punching shear, which is critical for this type of construction, can be resolved cost efficiently and dependably with the reinforcement bar schock bole. By simplifying slab reinforcement at column locations and eliminating column capitals, stirrup cages, or i beam shear heads. Efficiency of various punching shear reinforcement systems. Create punching shear checks tekla structural designer user. Punching shear strength of reinforced concrete slabs without. If the design of v rd,max was performed successfully, the required punching shear reinforcement is determined in the next step. If punching ratio of column on raft foundation 30 thick is 1. I have never yet had to deal with punching shear reinforcement as i usually prefer to increase the slab depth or provide a drop panel, but in this particular job it cant be achieved. Punching shear checks for walls, point loads, and nonconcrete columns. On the other hand, a limited number of analytical work is done using selfdeveloped programs, commercial software, or by utilizing mathematical model.
There are generally 4 methods used to overcome shear failure in general. Design room linkstudpsr specialists in punching shear. What are the solutions for punching shear failures in a. Aug 14, 2018 in the safe interface, click the displayshow punching shear design and the punching shear capacity ratios shear reinforcement will be displayed. Another solution, if the concrete shape is not fixed, would be to add a drop panel to the soffit of the beam at the support as you would do for a flat slab but only for the width of the beam, not l3. Pdf alternative punching shear reinforcement for rc flat. Safe technical knowledge base computers and structures, inc. Shearail prefabricated punching shear reinforcement system for flat, piled and posttensioned slabs. If necessary, safe designs tie and shear stud punching reinforcement. The new halfen hdbz punching shear reinforcement now allows an even more efficient and economic design of foundation slabs and single foundations. Pdf alternative punching shear reinforcement for rc flat slabs. You can do this in the properties window by specifying the point load orientation in relation to the global y axis. Jordahl expert software for punching shear reinforcement. Hdbf punching shear reinforcement in element slabs 28 29 tender speci.
The latest version of ancons shearfix software is 5. The filigran punchingshearreinforcement fdb is the second generation of punching shear reinforcement that has been optimised for flat slabs using the filigran construction method. With better material properties than studs from smooth bars, armata provides more efficient design against punching shear failure in flat slabs. Punching shear design according to eurocode 2 in rfem. Structural analysis software rfem and rfpunch pro addon module for punching shear design of reinforced concrete surfaces acc. Let us take a look at a 2500mm thick pile cap supported with 5 numbers of piles in figure 1. Momentrelease and rigidzone options define kinematic relations where vertical and slab systems interconnect. For the flat slab with the general arrangement as shown below, let us design the punching shear for column b1 given the following design information.
Design example of punching shear in slabs eurocode 2. On the other hand, the punching shear strength depends of the column location on the footing, either interior, edge or corner, per the expression. So for effective control of punching shear the design is necessary. If the hypothetical maximum punching shear stress exceeds the allowable value by a moderate amount, punching shear reinforcement may be provided to bring the. Punching strength with shear reinforcement firstly, one has to check if the design shear. Ancon shearfix punching shear reinforcement system used within a slab to provide additional reinforcement around columns, ancon shearfix provides an ideal solution to the design and construction problems associated with punching shear.
It is mainly used to increase the punching shear capacity of elevated concrete slabs and slabs on grade without increasing their thickness. Ancon shearfix is designed to suit the specific requirements of each application. The latest version of ancons shearfix software is 4. Aug 06, 2019 the two axis systems are locked together, so if the column is rotated, the punching check axes also rotate. There are many reinforcement solutions available for increasing the punching shear capacity, such as bentup bars, stirrups, double headed shear studs, structural steel shear heads, shear bands. Pointdisplacement load assignment is available for support conditions. The system consists of doubleheaded studs welded to flat rails, positioned around the column head or base. Punching shear in beam structural engineering general. Punching shear safe 2016 tutorial example and practical.
Optional consideration of minimum moments according to en 1992. Punching shear how to design against punching shear forces. Integration of design software by the halfen shear reinforcement rails producer. Free software is available from ancon that simplifies the design of punching shear reinforcement. When you apply a punching shear check to a point load, you must manually define the punching shear check z axis orientation. The ancon design program simplifies the specification and ordering of a shearfix system. Easy to use application for analysis of punching shear of reinforced concrete columnslab connection.
The fdb enables punching loads that are more than doubled factor 2. By simplifying slab reinforcement at column locations and eliminating column capitals, stirrup cages, or i beam shear heads, they enable efficient design and rapid. Cads punching shear designer is a software application which performs rapid and costeffective design solution of punching shear calculations for reinforced concrete flat slab structures. It leads to the formulation of a new failure criterion for punching shear based on the rotation of a slab. Jul 17, 2014 punching shear is a phenomenon in flat slabs caused by concentrated support reactions inducing a cone shaped perforation starting from the top surface of the slab. Halfen hdb punching shear and shear reinforcement 4 7 hdb punching shear reinforcement 5 hdbs shear reinforcement 6 product overview 8 halfen hdb as punching shear and shear reinforcement 8 calculation. A sw area of shear reinforcement in one perimeter around the column subject to a sw,min s r radial spacing of perimeters of shear reinforcement. Dsa rails consist of steel doubleheaded dsa studs welded to a steel shape.
Two way punching shear concept explained and flat plate example csa a23. From the above discussion we can see that the providing the shear reinforcement is the best method to solve the problem of punching shear. Punching shear reinforcement asnzs aunz code issues. Punching shear resistance with punching shear reinforcement. Punchingshear force vu should be smaller than the column reaction, and similar to the value of column reaction minus column weight and load within the shear perimeter. Ed, is to be controlled at the critical section, as described in section 2. The required punching shear reinforcement is calculated according to the adjusted expression 6. Your flexural shear reinforcement will be full width of the beam but you should only consider that which is in the punching zone. With better material properties than studs from smooth bars, armata provides more efficient design against punching shear failure in flat slabs peikkos armata is primarily used to increase the punching shear resistance of castinsitu concrete slabs without.
Safe punching shear problem software issues structural. If the maximum punching shear stress calculated does not exceed the allowable value, the section is considered safe. The jordahl expert punching shear reinforcement jda is used to design flat slabs, ground slabs, precast slabs and footings. This criterion correctly describes punching shear failures. Punching stresses generally arises when a concentrated load is applied to a small area of slab. Basic principles 9 14 pointload supported slabs 9 design concept 10combination of system elements 15 combinations of hdb. Used within a slab to provide additional reinforcement around columns, ancon shearfix is the ideal solution to the design and construction problems associated with punching shear. Calculate the required asw shear reinforcement for n perimeter check if the punching shear stress at the loaded area face v exceeds 0. The calculations are done in accordance with bs en 1992.
Introduction to punching shear reinforcement 4 advantages of the jordahl punching shear reinforcement jda 5 design according to eta6 6 9 summary of proofs 6 round cut guide 6 design load 7 punching shear resistance without punching shear reinforcement 7 punching shear resistance with doubleheaded anchors 8. Punching program for verification of punching shear resistance of concrete slabs according to en 199211 and en 19922. Punching shear reinforcement design program ancon ltd. Decon studrails are a proven, costeffective solution to resist punching shear at slabcolumn connections in elevated slabs and foundation mat slabs, as well as bursting stresses in posttension anchorage zones.
Numerical and graphical display of results 3d, 2d, and in sections punching shear design with or without punching shear reinforcement. Although generally preceded by flexural failure, punching shear is a brittle failure mode and the risk of progressive collapse requires a higher safety class in structura. A mechanical explanation of the phenomenon of punching shear in slabs without transverse reinforcement is presented on the basis of the opening of a critical shear crack. The program is able to analyse both plain and reinforced concrete structures. Ancon shearfix punching shear reinforcement system used within a slab to provide additional reinforcement around columns, ancon shearfix provides an ideal solution to the design and construction problems associated with punching shear related links. Punching shear checks in pile caps the structural world. Dsa punching reinforcement is a shear rail system approved by icc evaluation service. There are a couple of reasons the results in adaptfloor pro may differ, specifically to the ec2 code. Punching shear reinforcement filigran tragersysteme gmbh.
For the ystrips, csy4 have maximum shear value in c4. Punching shear capacity in slabs without punching shear reinforcement. As far as i can see the only methods referenced in as3600 to increase shear capacity is the use of a shear head with no guidance given, or provide closed ties in. Punching shear designer, reinforced concrete slabs cads uk. Max frank offer a punching shear reinforcement customised design program which automatically calculates the most costeffective design solution for. Punching shear is a phenomenon in flat slabs caused by concentrated support reactions inducing a cone shaped perforation starting from the top surface of the slab. It is possible that punching shear failures can occur around walls especially walls with a short length.
In this video, we investigate how to analyze a slab for punching shear, how to design rebar and stud rails, and some theory, tips and tricks. This is a shear stud rail system, sometimes called ssr on drawings. The concrete shear strength in oneway action is defined by the expression. Unbalanced moments mu2 and mu3 should be similar to the column moments at the top of the column times the reduction factor aci 318 gama v. The studs are welded to the rail at centres determined by. The punching shear capacity in slabs without punching shear reinforcement. Punching shear reinforcement jdaftkl jordahl jordahl. Feb 06, 2019 in this video, we investigate how to analyze a slab for punching shear, how to design rebar and stud rails, and some theory, tips and tricks.
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