方形闸门井基坑开挖支护结构离心模型试验研究  

Centrifugal model test on stress and deformation of supporting structure during excavation of a square gate shaft foundation pit

作　　者：汪波 孙慧[3] WANG Bo;SUN hui(Ji′nan Geotechnical Engineering Company,Ji′nan 250100,China;Ji′nan Survey and Mapping Research Institute,Ji′nan 250100,China;Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China)

机构地区：[1]济南岩土工程公司,山东济南250100 [2]济南市勘察测绘研究院,山东济南250100 [3]长江科学院水利部岩土力学与工程重点实验室,湖北武汉430010

出　　处：《人民长江》2025年第3期178-183,共6页Yangtze River

基　　金：国家自然科学基金项目(51608351);天津市自然科学基金项目(18JCYBJC22600)。

摘　　要：为了研究方形闸门井深基坑在开挖过程中支护结构的受力和变形规律,选取深圳一地铁隧道系统工程段为研究对象,对现场实际情况进行概化,并展开不同开挖步的离心模型试验,通过相似原理等方法计算现场原型深基坑开挖引起的地连墙水平变形、地表沉降和墙侧土压力等变化规律。试验结果表明:地连墙侧向变形先增加后逐渐减小,呈中间大、两端小的“胀肚”形;地面沉降呈“凹槽”形,随基坑开挖过程逐渐增大,峰值为7.16 mm;地连墙墙侧土压力变化呈现镜像“S”形,地连墙墙后土压力值与基坑深度呈现明显的非线性特点,在基坑开挖深度较小时,土体受到压应力作用,随着开挖深度的增加,土压力值由正值转变为负值,正值和负值的大小均是先增后减;开挖起始阶段,地连墙墙体受到扭转作用较小,相应弯矩变化值较小,随着基坑开挖的进一步加深,扭转作用加强,相应弯矩值逐渐变大;基坑支撑杆内力在开挖过程中随着支撑杆埋深的增大是先增大后减小。研究成果可为深基坑设计和开挖施工提供参考。In order to study the stress and deformation law of supporting structures during the excavation of a square gate shaft foundation pit,a subway tunnel system engineering section in Nanshan District of Shenzhen City was taken as the research object.The actual situation of the site was reasonably generalized and a centrifugal model test with different excavation steps was carried out.Through the similarity principle and other methods,the horizontal deformation of the diaphragm wall,the surface settlement and the earth pressure on the side of the wall caused by the excavation were calculated.The test results showed that the lateral deformation of the diaphragm wall increased first and then decreased gradually,showing a bulging belly shape with big middle and small ends.The ground subsidence was in a shape of groove,which gradually increased with the excavation process,and the peak value was 7.16 mm.The soil pressure on the side of the diaphragm wall was mirror S type,and the soil pressure value behind the diaphragm wall was obviously nonlinear with the foundation pit depth.When the excavation depth of the foundation pit was small,the soil was subjected to compressive stress.With deepening of the excavation,the soil pressure changed from positive to negative,and the positive and negative values all increased first and then decreased.In the initial stage of excavation,the torsion effect of the diaphragm wall was small,and the corresponding bending moment change value was small too.With the further deepening of foundation pit excavation,the torsion effect was strengthened,and the corresponding bending moment value gradually became larger.The internal force of the foundation pit support rod increased first and then decreased with the increasing buried depth of the support rod during the excavation process.The research results can provide reference for deep foundation pit design and excavation construction.

关 键 词：深基坑 方形闸门井 离心模型试验 地表沉降 地连墙变形 

分 类 号：TU43[建筑科学—岩土工程]