Trench Box Design/Analysis - Reference Availability 1

[lemmiwinksownz]

Hello,

How are prefabricated/modular trench boxes designed? Are they analyzed the same way as braced sheet pile? Which codes govern the design process of trench boxes?

If you could recommend any literature for trench box design it would be much appreciated.

Thanks

 

[oldestguy]

Regardless of what you come up with, don't forget these get very rough handling. Let's suppose it is stuck down there and you have to get it out. I suspect many are built with the idea of how to avoid wrecking it in the process as one of the loads involved.

 

[bridgebuster]

Yes, trench boxes are designed as braced excavations. Typically, they're governed by OSHA 29CFR 1926.650 to .652 (see link) although the locality you're working in may have stricter design requirements that need to be followed.

Link

There are commercially available systems on the market. See attached for one of them.

 

[chicopee]

And once you have come up with the design, nameplates are to be affixed inside the trench boxes and the nameplates should list soil types, allowable depths and other requirements. I believe that the old requirement of no more than two trench boxed stacked on the top of each other is still in effect

 

[lemmiwinksownz]

Interesting.

Is it common for general contractors to produce their own makeshift "trench-boxes?" I realize shoring systems have to be approved by a PE and meet OSHA regulation, but how common is it to see GC's rig something of their own?

 

[bridgebuster]

I work mainly in NYC, hardly see trench boxes. Braced timber is common for sewer manhole work. HDD has replaced a lot of trenching for major pipe (water main and sewer)installations.