水文地质工程地质2025，Vol.52Issue(1)：53-61,9.DOI:10.16030/j.cnki.issn.1000-3665.202401044
基坑施工抽水诱发土体渗透破坏的临界抽水量预测
Predicting the critical drainage induced by soil seepage failure during pumping in foundation pit construction
摘要
Abstract
In the construction of foundation pits with shallow groundwater levels,improper control of pumping strength often leads to soil penetration failure,resulting in engineering accidents,casualties,and property losses.Currently,existing research mainly focuses on soil conditions,settlement deformation prediction,construction pumping measures,etc.,and rarely involves the critical pumping quantity.However,the critical pumping quantity is a key parameter for pumping safety in foundation pit construction and there is no effective method to calculate or test this parameter.Based on Darcy's law and the equivalent infinitesimal formula,and the formula for calculating the permeability coefficient of pumping tests recommended by the specification for borehole pumping test of hydropower projects(NB/T 35103-2017),this study deduced the expressions of critical pumping quantity of the seepage failure under four conditions,including submersible incomplete hole,submersible integral hole,confined water incomplete hole and confined water integral hole.To ensure that the calculated result is more effective,the calculated expression was modified by introducing correction coefficient.The results indicate that the relationship between the critical drawdown volume for inducing soil permeability failure in the four cases and the critical permeability velocity is linear,suggesting that measuring the critical permeability velocity of the soil at the site can determine the critical drawdown volume.In a case study of basement excavation in Hohhot,it is found that the cobble layer has the highest potential for water permeability failure.Laboratory measurements revealed a critical permeability velocity for its failure of 7.1×10-4 m/s.To prevent damage to this layer during pumping,an artesian well SJ1 with a designed critical drawdown volume of 174.45 m3/d was used,and actual pumping volumes were controlled within 150 m3/d without observing any permeability failures,demonstrating applicability of the proposed method.Therefore,compared to existing qualitative experience-based methods for predicting critical drawdown volumes in basement excavation,the quantitative calculation method holds greater practical application value.关键词
基坑施工/渗透破坏/临界渗透速率/临界抽水量/渗透系数/钻孔抽水Key words
foundation pit construction/seepage failure/critical seepage velocity/critical pumping quantity/permeability coefficient/borehole pumping分类
天文与地球科学引用本文复制引用
姜伏伟,唐书君,邓晓飞,李振超,张发旺,尹鸿远..基坑施工抽水诱发土体渗透破坏的临界抽水量预测[J].水文地质工程地质,2025,52(1):53-61,9.基金项目
国家重点研发计划项目(2023YFC3710001) （2023YFC3710001）
国家自然科学基金项目(42467024 （）
41130637) （）
东华理工大学博士科研启动基金项目(DHBK2022015) （DHBK2022015）
青海九零六工程勘察设计院有限责任公司科技项目(2023-KJ-07) （2023-KJ-07）
