考虑空间变异性的基坑开挖地表沉降分析  

ANALYSIS OF GROUND SURFACE SETTLEMENT FOR DEEP EXCAVATION CONSIDERING SPATIAL VARIABILITY

作　　者：闫升飞 胡聪伟 张拥军[2] YAN Shengfei;HU Congwei;ZAHNG Yongjun(China Railway Construction Group Second Construction Co.,Ltd.,Shandong Qingdao 266100,China;Qingdao University of Technology,Shandong Qingdao 266525,China)

机构地区：[1]中铁建工集团第二建设有限公司,山东青岛266100 [2]青岛理工大学,山东青岛266525

出　　处：《低温建筑技术》2025年第3期147-150,共4页Low Temperature Architecture Technology

摘　　要：为探讨岩石地层弹性模量的空间相关距离对基坑开挖引起的周边地表沉降的影响,文中以山东大学齐鲁医院二期项目的深基坑工程为背景,并基于拉丁超立方抽样-蒙特卡洛方法结合FLAC 3D数值软件,建立随机有限差分模型。通过改变岩石地层不同横向和竖向自相关距离,得出当岩石地层的弹性模量服从对数正态分布时,地表沉降的概率分布与对数正态分布形式吻合较好。下层岩石弹性模量相关距离变化对基坑周边地表沉降影响较小,在CLx岩石=4.5CLx软土时地表沉降均值取得最大值,为最不利工况。与确定性计算的结果相比,总体而言随机场模型计算的结果均较大,在进行分析研究时有必要考虑岩土体的空间变异性。A deep excavation project in Shandong is taken to investigate the impact of the spatial correlation distance of the elastic modulus of rock strata on ground surface settlement induced by deep excavation.By the Latin hypercube sampling-Monte Carlo method in FLAC 3D numerical software,a stochastic finite difference model is established.By varying the horizontal and vertical autocorrelation distances of the rock strata,the study finds that when the elastic modulus of the rock strata follows a lognormal distribution,the probability distribution of ground settlement also fits the lognormal form well.The results indicate that changes in the correlation distance of the lower rock strata’s elastic modulus have a relatively minor impact on ground settlement around the excavation.The most unfavorable condition occurs when the correlation distance of the rock strata in the x-direction is 4.5 times that of the soft soil,where the mean surface settlement reaches its maximum value.Compared to deterministic calculations,the results obtained from the stochastic field model are generally larger,highlighting the necessity of considering the spatial variability of geotechnical properties in analysis and research.

关 键 词：空间变异 复合地层 空间相关距离 地表沉降 

分 类 号：TU475[建筑科学—结构工程]