土体GHS与HSS模型选择对基坑数值分析结果的影响  

Influence of GHS and HSS model selection on numerical analysis resultsof foundation pit

作　　者：张家勇 ZHANG Jiayong(China Railway First Bureau Group Xiamen Construction Engineering Co,Ltd,Xiamen 361000)

机构地区：[1]中铁一局集团厦门建设工程有限公司,福建厦门361000

出　　处：《福建建筑》2023年第9期82-88,共7页Fujian Architecture & Construction

摘　　要：为对比基坑工程土体本构模型选择对计算结果的差异,利用Plaxis软件,坑底土体分别选用小应变刚度模型(HSS)与广义土体硬化模型(GHS)进行对比分析。结果表明:基坑开挖后,坑底相邻区域第三主应力显著降低,HSS模型坑底刚度与第三主应力相关,GHS模型坑底刚度与当前平均主应力和前期应力相关,GHS模型坑底的剪切刚度E_(ur)显著大于HSS模型;在基坑开挖各阶段,采用GHS模型在基坑开挖全程都获得显著更少的隆起量。当开挖至坑底地层(开挖10 m)时,可减少45.4%的坑底隆起量极值;采用GHS模型计算的基坑底下卧盾构隧道的变形量,小于采用HSS模型计算的变形量,更加接近于工程实测值。In order to compare the difference between the calculation results of the selection of soil constitutive model of foundation pit engineering,the small strain stiffness model(HSS) and the generalized soil hardening model(GHS) were selected for the comparison and analysis of the soil mass at the bottom of the pit using Plaxis software.The results show that the third principal stress in the adjacent area of the pit bottom decreases significantly after the excavation of the foundation pit,the rigidity of the pit bottom of the HSS model is related to the third principal stress,the rigidity of the pit bottom of the GHS model is related to the current average principal stress and the previous stress,and the shear rigidity of the pit bottom of the GHS model is E_(ur) is significantly greater than HSS model;At each stage of foundation pit excavation,the GHS model can obtain significantly less uplift in the whole process of foundation pit excavation.When the excavation reaches the bottom of the pit(10m),the maximum uplift at the bottom of the pit can be reduced by 45.4%;The deformation of shield tunnel under the foundation pit calculated by GHS model is less than that calculated by HSS model,which is closer to the measured value of the project.

关 键 词：小应变刚度模型 广义土体硬化模型 基坑工程 地铁隧道 数值分析 

分 类 号：TU4[建筑科学—土工工程]