摘要
为研究隧洞掘进机(tunnel boring machine,TBM)掘进下隧洞围岩的损伤特征,选取南水北调西线工程为背景工程,针对隧洞围岩TBM掘进后的损伤进行了系统的研究与分析。根据板岩在室内试验中表现出来的脆性和屈服后强度特性,提出了以黏聚力弱化-摩擦角强化(cohesion weakening and frictional strengthening,CWFS)脆性模型为基础考虑岩体屈服后损伤的本构模型,通过VC++编译dll动态链接库,并将其植入FLAC3D程序中。应用神经网络和遗传方法等优化算法对本构模型中的参数进行了反演分析,并以室内三轴压缩试验为依据,对该本构模型进行了验证。结果表明,提出的考虑损伤的CWFS模型可以较好地反映板岩的弹性特征、屈服后的强化特征、脆性破坏特征和破坏后残余强度特征。以该模型为基础,模拟了南水北调西线隧洞在TBM掘进条件下隧洞围岩的变形特性、应力发展规律及其损伤演化特征,并与基于Mohr-Coulomb本构关系的计算结果进行了对比分析。提出的考虑损伤的CWFS模型能更好地反映隧洞掘进后围岩损伤特征,即损伤沿着弱势区域发展的规律。
The West Route of the South to North Water Transfer Project is taken as the engineering background and the excavation disturbed zone in surrounding rock of tunnel by tunnel boring machine（TBM） driving are studied.Considering the rock post-yield damage,a new constitutive model based on the cohesion weakening and frictional strengthening（CWFS） brittle model is proposed and is implanted to FLAC3D program by debugging dll in VC＋＋.Based on the results of triaxial compression tests,this constitutive model is verified through parameter back analyzing by optimization algorithm such as neural network and genetic algorithm.The results show that the model can reflect the elastic characteristic,post-yield characteristic,brittle failure and post-failure residual strength characteristic of slate.Based on this model,the surrounding rock deformation characteristics,stress evolution law and damage characteristic of TBM driving of the South to North Water Transfer Project are studied and also compared with the results by Mohr-Coulomb constitutive model.Finally,the conclusion is drawn that the constitutive model proposed can better reflect the damage rule of the surrounding rock daring TBM driving,i.e.the damage develops along the weak zone.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第11期3420-3426,共7页
Rock and Soil Mechanics
基金
国家科技支撑计划课题子题(No.2006BAB04A06)
中科院方向性项目(No.KZCX2-YW-109-3)
国家科技支撑计划项目(No.2007BAF09B01)
关键词
围岩损伤
隧洞掘进机模拟方法
CWFS损伤模型
损伤量
damage of rock mass
the numerical simulation method of TBM driving
CWFS damage model
damage quantity
