Designed Ground Water Level for Sheet Pile Wall Design 1

[ynnuseel0106]

Does anyone know why there are two design ground water levels for the design of ELS system? The highest groundwater level is for ULS checking, i.e. overturning, strutural member design, and the lowest groundwater level is for SLS checking, i.e. dewatering settlement. Why a lower ground water level is more critical to induced settlement??

 

[Panars]

A lower ground water level will induce more settlement because the effective stresses in the soil increase.

 

[oldestguy]

I trust your method has appropriate factor of safety of sheet depth against quick conditions at the base of the excavation.