Study on Influence of Dissipation of Negative Pore Water Pressure on Heave of Pit Base

Excavation will induce negative excess pore water pressure in soft soil. In this work, the dissipation rule of negative excess pore water pressure was studied. Analytical formulas for calculating the negative excess pore water pressure and the heave of pit base were derived based on one-dimensional consolidation theory and Terzaghis effective stress principle. Finally, the influence of the permeability coefficient and the stiffness of soil mass on the heave of pit base was analyzed through a numerical example. The calculated result showed that the dissipation of the negative pore water pressure causes the decrease of effective stress and the heave of pit base.