Temporary Sheet pile ERS

[wheels72]

The California Trenching and Shoring Manual states that for systems subject to dynamic loading (adjacent to railroads, pile driving operations, etc.)use wall friction = 0. What is the reasoning(theory) for this?

 

[ishvaaag]

I don't know what IS the theory but I can imagine what one theory might be: upon vibration at some time the ground separates from the retention system. In fact the ground is being consolidated by the vibratory movement. That they decide add that statement as one of the clauses leading to sound design needs to be calibrated with the other provisions therein; you could get a similar result stating higher mandatory earth ground push and keeping some standing friction. Since most codes are in some way derived from practical considerations, the totum in the code was seen to produce a sound design, one can't take just a part of it as the specification, since all comes together.