一种软土地区深基坑涌水量计算方法

摘要

The water inflow of foundation pit is an important parameter in dewatering project of foundation pit, which will affect the amount of dewatering wells,the decline of water level and the subsidence of ground.Based on the characteristics of soil layers and seepage nets around deep foundation pit in soft soil area ,the water inflow can be divided into water storage in foundation pit and seepage of the bottom and from outside to inside of foundation pit, their respective formulas are presented.A calculation method on water inflow of deep foundation pit in soft soil area was proposed.Combined with the main structure of Tianjin subway station, the water inflow calculated by the method is consistent with the results of f ield pumping test and local construction experience.The measured value of a deep foundation pit in Shanghai show that the method has good applicability in soft soil area.%基坑涌水量是基坑降水工程的一项重要参数,影响降水井数量、水位降幅和地面沉降.基于软土地区深基坑地层特性和渗流场流网特点,将基坑涌水量分为基坑内储水量和基坑底及基坑外向基坑内的渗流量,并提出各自的计算公式,从而给出了一种深基坑降水工程涌水量计算方法.结合天津地铁一站主体结构基坑,用该计算方法所得基坑涌水量与依据现场抽水试验和施工经验所得结果一致.经上海一深基坑涌水量实测值进一步验证,本文所提方法在软土地区具有较好的适用性.