Publication Abstract

Proceedings - Fourth International Conference - Theory and Practice of Piling and Deep Foundations in China, 1991, Beijing, China, (DFI)

11 Vacuum Wellpoints for Slope Stabilization in the Foundation Pit During a Dry Dock Construction
Mai Yuanjian; Fourth Harbour Engineering Bureau of the Ministry of Communications, China

The stabilization effect in large excavation slopes with vacuum wellpoints system during construction of a dry dock located in Guangzhou is introduced in this paper. In-situ observations indicate that the effect of wellpoints for decreasing seepage in slope is remarkable even though the muddy sitty clay in it has poor permeability and the slope can remain its stability well. Meanwhile, a non-linear partial differential equation has been set up to the whole unsteady seepage process as water level in the foundation pit excavated under water goes down to the bottom and so does the seepage in slope due to dewater by vacuum wellpoints system at the same time. And the finite-differential method has been used to solve the equation mentioned above, which differs from conventional ways where the equation will be linearized firstly. Since the water heads in slope with wellpoints dewatering are more variable, it is necessary to keep non-linear. The calculation results are in good accordance with observation. Vacuum wellpoint for slope stabilization in this work is successful.

 article #15; publication #38 (IC-1991-CH)