Tutorial for Punnching Shear reinforcement

„ Punching Shear“ is a type of slab reinforcement that is placed in a zone around column and serves to prevent Slab-Column connection failure.

„ Punching Shear“ is made by placing an additional steel in a slab around column, up to predefined distance from column face.

1. This additional steel can be in form of Links that will be attached to the slab main steel mesh.

2. As a Ties that are hooked for main mesh, or hooked onto mesh of additional bars around the column.

In this tutorial, we will show example of Punching Shear reinforcement done with links, attached to slabs main reinforcement ( main mesh).

Here is the case of links distributed on a distance 180+900=1080 mm from column edge at 150mm spacing.

Previous Output AddElements Keyplan

Previous Output Other Needed Documents WO-Z1-F1- PunnchingShearReinforcement ID01-ID02.

Lets start with more simple example, the ID 01 .When working on this type of Punching shear you must remmember two things :

1. Links are attached on slabs main reinforcement mesh

2. Your „ Basic File“ ( IFC drawing) with steel information is often given as a „ TYPICAL detail“ which means that your column dimmensions may be differet that IFC dwg and your links will need to be updated as per your CO.

NOTE : Example of item #2 difference between IFC and your case, here we can see that on IFC dwg column is rectangular, while our column has round cross section and different dimmensions.

NOTE : As you can see, links are T10@150 ,the big link covers 5 Top and Bottom bars spacing, while two small ones cover one spacing of main reinforcement.

As per WIP, for Punching shear reinforcement, we should follow IFC drawing and take all necessary information from it.On IFC section you can see that the largest link covers 6 Top and Bottom bars of slab main reinforcement ( red bars).

Take information about your slab main mesh reinforcement from keyplan.

Start drawing from plan view, by drawing 6 bars in each way, on 150mm spacing.

NOTE : Slab main mesh is always drawn symetrically to the column axis.

Place first set of links at 180 mm distance from the column edge.

180 mm

180 mm

There is something interesting in this job, that you should pay attention to :When you look at your sample ,you can see that is actualy a sample for Punching Shear reinforcement done with Ties, and not with Links ( which is case here).

180 mm

180 mm

This means that final presentation will not look like this, but instead, like IFC. If you happend to have this situation, raise an RFI with request for another sample, but there is no need for you to wait for an RFI reply, you can still match with this SAMPLE a BM description text size and style, SHAPE CODES, LAYERS and DIMMENSION LINES.

Distribute the rest of the links @150mm spacing until 900+180=1080mm from the edge of the column.

New sample received in RFI reply.There is no need to show main reinf. bars, so delete blue bars. Magenta rectangle is border of Punching Shear,and it is just for help, so delete it too.

New sample received in RFI reply.As you can see, as per this sample, we should provide additional section in same direction, but in front of the existing one, so the CO of the section will remain the same, but reinforcement that will be shown is different.

Do ofset for cover 30 mm to get shape of main mesh.

h=400-30-30=340mmA1=150+14+2 x 10=166mm 165mmA2=5x150+14+2 x 10=766mm 765mm

First we will draw reinforcement on section through column and slab.

New sample received in RFI reply.

Do ofset for cover 30 mm to get shape of main mesh.

h=400-30-30=340mmA1=150+14+2 x 10=166mm 165mmA2=5x150+14+2 x 10=766mm 765mm

Now to draw reinforcement on section through slab.

Put leaders and bm text on plan view as per sample

The look of finished PS ID 01

Now we have to do reinforcement of the ID 02 .

Punching Shear ID 02 has the same steel information as ID 01 (Links T10@150 and 1080mm from the edge of the column) ,but the CO is different.

The slab thickness is 600mm ( ID01 slab Thk=400mm) and there is an opening in a slab, which means that links height will be 200mm greater and we will have to cut bars in a opening.

The plan view distribution of links on three sides is the same as for ID01 .

Now lets see what happens on the side where we have an opening in a slab.There will be one set of links same as on other three sides.There will be 6 set of a small link that cover one spacing of main steel, and one link that covers two spacings .

Since the section line is on the same position as for ID 01, I will skip the explanation of how to draw section,and just show you slides of step-by-step proces.

The look of finished PS ID 02

And now, work finished and ready for closing the job Don’t forget to put user Id, Job Id, Element name, and WIP and Sample versions information as per Job Instruction.

The End