Question

A 30-ft-deep cut for a basement excavation is specified to be sloped at 1:2 (one horizontal to two vertical). The upper 60 ft of soil at the site consists of a homogenous clay with a density of 90 PCF and unconfined compressive strength averaging 2,400 psf. The water table is in great depth.

• Question: please discuss if the cut can be made?

• Question: If so, what is the factor of safety for the slope? Please show your calculation.

• Question: Is the slope safe enough for normal construction activities on the bottom of the excavated area? Please discussion this problem from the view point of the OSHA regulations.

Answer 1