岩土力学2017，Vol.38Issue(11)：3295-3303,3318,10.DOI:10.16285/j.rsm.2017.11.027
软土区基坑预降水引起支护墙侧移的典型参数影响研究
A parametric study of lateral displacement of support wall induced by foundation pre-dewatering in soft ground
摘要
Abstract
Strata in Tianjin area are featured as an altemated multi-aquifer aquitard system.Based on this strata condition,lots of numerical calculations investigate the effect of deep foundation pre-dewatering on lateral displacement of support wall in soft ground under different construction conditions,including dewatering time (t),dewatering depth (Hd),pit length (L) and pit width (b).The calculation results were compared with relevant field data,and nonlinear regression analysis was then conducted based on the calculation and observation results.The results indicate that the maximal lateral displacement of support wall (δhm) increases nonlinearly with t,and the growth rate decreases continuously.In the first few days of the dewatering,lateral displacement of support wall development can occupy large proportion of its stable value during pre-dewatering.Moreover,Hd has a great influence on the δhm development and the depth of wall with cantilever-type deflection (Hc).In general,δhm and Hc will be larger with the increase of Hd.Specifically,before Hd reaches the second permeable stratum of the field,δhm increases linearly with Hd by a small scale.Otherwise,the growth proportion of δhm with Hd increases greatly.Before Hd reaches the center location of the thick aquitard,Hc increases synchronously with Hd increased,and otherwise,the Hc increment is apparently greater than the Hd increment.Furthermore,as to the same pit width (b),when the pit length (L) reaches a specific value,the corner effect induced by dewatering always appears at a specific distance from the pit corner along the pit length direction.In practical pre-dewatering,cross wall can be used to partition the pit into some parts,and let the ratio of cross wall spacing (Scw) to b be less than 4,or let Scw / Hd be less than 3.7,using the comer effect to effectively reduce the maximal lateral displacement of support wall induced by pre-dewatering.关键词
软土地基/深基坑预降水/支护墙侧移/有限元计算/边角效应Key words
soft ground/deep foundation pre-dewatering/lateral displacement of support wall/finite element calculation/corner effect分类
建筑与水利引用本文复制引用
曾超峰,薛秀丽,郑刚..软土区基坑预降水引起支护墙侧移的典型参数影响研究[J].岩土力学,2017,38(11):3295-3303,3318,10.基金项目
国家自然科学基金项目(No.51308209,No.51578164,No.51708206,No.11602083) （No.51308209,No.51578164,No.51708206,No.11602083）
滨海土木工程结构与安全教育部重点实验室开放课题(No.2017-KF03) （No.2017-KF03）
湖南省自然科学基金项目(No.2016JJ6044) （No.2016JJ6044）
湖南省教育厅项目(No.15C0557).This work was supported by the National Natural Science Foundation of China (51308209,51578164,51708206 and 11602083),the Research Project of Key Laboratory of Coast Civil Structural Safety of the Ministry of Education (2017-KF03),the Natural Science Foundation of Hunan Province (2016JJ6044) and the Scientific Research Fund of Hunan Provincial Education Department (15C0557). （No.15C0557）
