Being manner in order to presume the rebound tonnage which it occurs due to the fact that

摘要

PPROBLEM TO BE SOLVED: To estimate the amount of rebound expected to occur during excavation of the ground with high accuracy, in advance. PSOLUTION: In this method for estimating amount of rebound, underground water is pumped from the soil in a deeper layer than a bottom face to be excavated through a well 7 provided in the soil to be excavated, then pumping is stopped to restore a level of underground water, and underground water pumping and restoring tests for measuring pressure of water, in a clearance in the soil and amount of displacement in the vertical direction during the period of time are conducted. The coefficient of deformation being a ratio of effective stress in the vertical direction in the soil in the deeper layer than the bottom face to be excavated to distortion is obtained, based on the values obtained by measuring the pressure of water in the clearance and the amount of displacement in the vertical direction by the underground water pumping and restoring tests to perform FEM analysis, by using the coefficient of deformation and estimate the amount of rebound. The ground is excavated by using the estimated value as reference for management, and underground water is pumped through the well, when the amount of rebound exceeds the estimated value to prevent increase of the amount of rebound, by reducing the pressure of water in the clearance. PCOPYRIGHT: (C)2009,JPO&INPIT