相邻双基坑开挖相互影响三维性状分析  

Three-dimensional Numerical Analysis on Interaction Effect of Twin Adjacent Excavations

作　　者：颜桂云[1,2] 陈福全[2] 林海[2] 

机构地区：[1]福建省土木工程新技术与信息化重点实验室,福建工程学院土木工程学院,福建福州350118 [2]福州大学土木工程学院,福建福州350116

出　　处：《建筑科学》2015年第7期94-102,共9页Building Science

基　　金：国家自然科学基金资助项目(41272299)

摘　　要：相邻基坑开挖引起围护结构和周围土体变形与基坑单独开挖存在较大的差异,目前较缺乏考虑相邻基坑开挖产生的相互影响及其空间效应的研究。以实际相邻双基坑工程为分析原型,建立其开挖的三维有限元模型,研究双基坑开挖的空间效应。分析了相邻基坑同步开挖和不同基坑间距对基坑间土体沉降、支护结构内力、支护结构位移、坑底隆起、坑外地表沉降等的影响,探讨基坑开挖角部刚度效应。结果表明：相邻基坑开挖影响支护结构的内力和位移分布;基坑间土体沉降产生叠加影响,沉降量大于基坑两侧地面;近端支护结构变形和坑底隆起小于远端。基坑角部刚度效应在一定范围内会较明显地限制土体变形和支护结构的位移,且角部刚度效应随开挖深度增大而增大。基坑间距对相邻基坑产生相互影响的范围为2.5~3倍基坑开挖深度。The deformations of supporting structures and surrounding soils caused by adjacent excavations are quite different from the of single excavation. Current researches about the interactional and spatial effect of adjacent excavations are seldom related. Three-dimensional finite element model of the actual twin adjacent excavations is established to study the spatial effect. The influences of the synchronous excavation and different distance between twin adjacent excavations on the soil settlement of the twin adjacent excavations,internal force and displacement of supporting structures,basal-heave and surface settlement outside the excavations are analyzed. The impacts of corner stiffness on the excavation characteristics are further discussed. The results show that the adjacent excavations affect the distributions of internal force and displacement of supporting structures. The superimposed ground settlement between the adjacent excavations is caused by adjacent excavations,and the settlement is larger than that of two sides of ground. Further,the deformations of supporting structures and basal-heave near the ground between the adjacent excavations are less serious than those far from the ground. The study also indicates that the effects of corner stiffness limit the deformations of soil and displacement of supporting structures in certain range,and these effects are greater as the excavation depth increases. Besides,the distance between the adjacent excavations which affect the characteristics of adjacent excavations varies from 2. 5 to 3. 0 times of the excavation depth.

关 键 词：相邻基坑 相互影响 基坑间距 角部刚度效应 三维分析 

分 类 号：TU473[建筑科学—结构工程]