Caisson construction

[JC]

What is the best, permanent liner to use for an 8'-6" diameter X 15'-0" deep caisson installed in very dense, gravelly sand with silt (GP-GM) with no groundwater detected?

 

[Ginger]

Why not use a concrete box culvert-type section for the caisson and use a bituminous mastic sealant in the seating joint for each unit. If there is no water present in the ground then you will not require a liner. Andy Machon

 

[JC]

Thanks, Andy, for your quick response. However, I did not relate enough information about this problem. This caisson is really a pit with 2' thick walls and base slab. My concern is with construction of the pit and not the design. The site consists of 8 pits and I was looking for the most efficient way of construction. The client has requested that the liner remain in place.