Abstract:

Pile driving engenders disadvantage influence to stability of warf slopes，first it brings the excess pore water pressure in the soil around pile to sharp increase; and this leads to decrease of the effective stress; second vibratory acceleration owing to piling brings adverse instantaneous inertial force to stability. The first is primary for stability of insensitive soil slopes. Distribution of the original excess pore water pressure has been studied; and based on popular expression of Biot concretion differential equation, analytical formula for excess pore water pressure resulted from pile driving has been set up. Considering disadvantage influence from piling, formula of safety factor of stability was set up based on strip dispart method. Stability analysis on a wharf slopes has been done considering sequence of driving construction; result shows that safety factor reduces evidently，excess pore water pressure dissipates gradually; and factor varies with working procedure of driving. In period of construction slope is most dangerous because of accumulation of the pressure value; and the excess pore water pressure dissipate mostly after three months since finish piling, safety factor approximates the value that calculated without taking influence of piling into account. So it is important to check stability of slope during driving.

Key words: driving, excess pore water pressure；slope, stability