topic Re: add two simple concrete blocks on the both sides in Structural Bridge Design Forum

add two simple concrete blocks on the both sides

evyzh2 — Sat, 04 Mar 2023 11:47:38 GMT

hello, I have made a 3D model of truss bridge, while i am required to add more support underneath , show how to support it .My thought is to add two simple concrete blocks on the both sides .

Could you please help me how to deal with it? If you can show me some steps of doing it , would be perfect.

I really appreciate it

Re: add two simple concrete blocks on the both sides

dave_geeves — Sat, 04 Mar 2023 13:34:54 GMT

Hi,

Thanks for posting this query on the forum and I will happily try to describe the steps needed, but first I will need a bit more information regarding the location of these concrete blocks. For example, are these blocks encasing, and acting compositely with, the bottom boom - in which case the concrete will almost certainly be in tension for all load cases and will therefore be cracked, so will not really be effective - or is the concrete representing an RC slab spanning between the booms. Or do you mean the concrete to be concrete diaphragms spanning transversely between the supports.

Could you please send a few sketches to show what you require and it would be useful if you could "zip up" your data file and attach it to your reply so that I could use this to show how it might be achieved. Thanks

Kind regards

Dave Geeves

Re: add two simple concrete blocks on the both sides

evyzh2 — Sun, 05 Mar 2023 08:34:02 GMT

Dear sir,

the bridge is 100m long and 24.1 width the truss height is 10m.My task is to add something on the both sides of the bridge in order to support the bridge.As shown below , Could you pelase tell me how to deal with it, You don't need to be exact

Re: add two simple concrete blocks on the both sides

dave_geeves — Mon, 06 Mar 2023 19:46:38 GMT

Hi,

My apologies for not understanding you correctly. From your diagram it looks like you wish to add concrete abutments at each end of the span as shown below.

This can be done a number of ways but I would suggest that using shell finite element in a vertical plane will achieve this . It is important to ensure that the relevant nodes in the finite element mesh are coincident with the end nodes of the truss to ensure continuity. If the truss is not actually integral with the abutments, such that the truss is connected to bearings sitting on top of the abutment, and that some degrees of freedom are not fully connected, then the abutment wall should be slightly lower than the bottom of the truss and then the bearings can be modelled as stiff short beam members connecting the truss to the abutment. Then "member releases" can be applied to the top of these short members to fully or partially release some of the degrees of freedom.

I have put together a short video to show how to create the abutments if they are fully connected to the truss ends but the short stiff members can be added into each of the sub-models as described above.

(view in My Videos)

I hope this helps. If this has answered your query then please mark my reply as a solution so that others may benefit. Thanks.

Kind regards

Dave Geeves