I have been questioned by a local authority for the feasibility of “pushing/driving” “timber planking” (Grade SC3 to 5, BS 5268) into sandy soil (C=0, Angle of fiction = 30 Deg.) by using hydraulic equipment.
Any person would kindly suggest, what are the component/formula of the forces to overcome the resisting stresses by sandy soil.
Component of resistant stresses by sandy soil may as follows:-
(1) Skin Friction of soil
(2) End Bearing Stress of soil
(3) Soil Displacement (I can’t find formula from text books, please help!)
(4) Any other forces not taken into account?
I can handle the Cals of buckling of timber planking due to force applying by the hydraulic equipment. However......
How can I demonstrate the timber planking can be pushed/driven into sand approx 1.0m to 2.0m depth within its working stresses. (Can’t find any reference from the legend “Foundation Design and Construction, M. J. Tomlinson)
In addition, would any person can suggest/quota any reference materials or reports, about the “self-retaining” time of sandy soil (C=0, Angel of Friction =30 Deg) at approx. 0.5m to 2.0m depth excavated trench. Such time is critical to allow workers installing timber shoring system at partly supported trench safely (max. depth of trench excavation, less than 5.0m).