Press Pit Design
Press Pit Design
(OP)
I have designed a pit (size 19’x10’x9.5’ deep) that will be located in an existing warehouse. Excavation will be down to 11’ below finish floor. A contractor has proposed drilling in concrete piers 18” dia. practically side by side as shoring. Then installing the 15” retaining wall. This seems like tremendous overkill and is very expensive.
Soil is cohesive so the contractor could bench or cut back at a 45 degree slope. However, this would require demolition and repouring of existing concrete floor. There is approximately 18’ of clearance AFF, which probably limits the installation of sheet piling.
I am looking for ideas on how to support the pit's sides during excavation. All feedback is welcome.
Soil is cohesive so the contractor could bench or cut back at a 45 degree slope. However, this would require demolition and repouring of existing concrete floor. There is approximately 18’ of clearance AFF, which probably limits the installation of sheet piling.
I am looking for ideas on how to support the pit's sides during excavation. All feedback is welcome.






RE: Press Pit Design
Alternatively, with such a little excavation using an internal bracing system might do the trick. This could be constructed of sheet piling (to hold the walls of the excavation) with a metal pipe connected to the sheet to prevent the walls collapsing inside the excavation. Naturally, a stage construction would be necessary to work around the struts. And you probably wouldn't want to do the whole excavation at one time.
RE: Press Pit Design
Alternative idea. Use caisson technology where the walls are built integrally above ground and the structure lowered by subexcavation. This will eliminate the trench shoring.