考虑渗流效应下基坑水土压力计算的新方法

用经典的土力学理论计算基坑支护结构上的水土压力时,由于没有考虑地下水渗流对基坑土压力的影响,造成计算所得数值和实测值相差较大，针对该原因,提出了同时考虑作用在水体上的黏滞力和作用在土体上的渗透力，建立微分平衡方程,求解得到计算新公式,它不但能够解释 “水土分算”的微观机理，而且证明了渗透力和黏滞力是分别作用在土体和水体上的一对作用力和反作用力,得到黏滞力和静孔隙水压力与土中的水的重力是一对平衡力的重要结论.通过算例计算表明，计算结果比较接近实测量.该方法对均质成层基坑工程，边坡工程均适用.

New method for calculation of water-earth pressure on foundation pit considering groundwater seepage

Nonconsideration of groundwater seepage is one of the main reasons why measured values of water-earth pressure on supporting structures are generally very different from those calculated with classic earth pressure theories.Mechanical effects of groundwater seepage on earth pressure were studied and the viscous drag force and seepage force were considered together.By setting up differential coefficient equations and constructing a set of entire new calculation expressions on the foundation pit were presented with consideration of groundwater seepage.It was proved that the viscous drag force and the water pressure around the earth are in equilibrium with the water weight.The results calculated with the new expressions were very close to the measured water-earth pressure values.This calculation method is universally applicable to excavation engineering and the stability analysis of earth slopes.