隧道爆破开挖围岩动力损伤效应数值模拟  

Numerical simulation of dynamic damage effect of surrounding rocks for tunnels by blasting excavation

作　　者：左双英[1,2] 肖明[2] 续建科[1] 史文兵[1] 

机构地区：[1]贵州大学资源与环境工程学院,贵阳550003 [2]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《岩土力学》2011年第10期3171-3176,3184,共7页Rock and Soil Mechanics

基　　金：贵州大学自然科学青年科研基金资助(贵大自青基合字(2007)049号)

摘　　要：采用数值模拟技术预估岩体开裂深度及爆破损伤影响范围对工程设计可以起到事先指导作用,对施工安全具有重大意义,其中科学的、合理的损伤模型及迭代计算方法是关键。基于FLAC3D程序的用户自定义本构模块,将考虑累积应变和荷载作用时间的Yang-Liu率相关动力损伤模型与Mohr-Coulomb弹塑性本构进行耦合,将围岩破坏过程中的损伤特性反映在荷载增量迭代计算中,形成了弹塑性动力损伤本构模型,详细推导了损伤应力修正迭代计算方法。对一圆形隧道爆破开挖进行模拟,探讨了爆破诱发的质点振动衰减特征及围岩损伤分布规律。分析结果表明,爆破产生的质点振动速度峰值与其所造成的损伤具有很好的相关性。该爆破损伤模型及模拟方法可以为类似工程提供一定参考。It can not only play a guiding role in engineering design in advance predicting the cracking depth and damaged range of surrounding rocks by blasting excavation in use of numerical simulation method,but also is of great significance to construction safety;in which,a scientific and reasonable damage model and iterative calculation method are most important key technique.Based on the user-defined constitutive modules of the fast Lagrangian analysis of continua in three dimensions（FLAC3D） procedure,Yang-Liu dynamic damage model dependent on strain rate considering cumulative strain and load time is embedded in Mohr-Coulomb elastoplastic model.The rock damage characteristic is reflected in the iteration calculation process of a incremental load;thus an elastoplastic dynamic damage constitutive model is formed.Subsequently,iterative format of damaged and modified stresses is derived in detail.In simulating a circular tunnel by blasting excavation,a discussion and analysis for characteristics of vibration attenuation and distribution rules of damage in surrounding rock mass induced by blasting are carried out.The calculation result shows that the vibration velocity peak is well correlated with the damage coefficient.The blasting damage model and simulation method can provide a certain reference to similar engineering.

关 键 词：爆破开挖 动力损伤本构模型 数值模拟 FLAC3D 

分 类 号：TU452[建筑科学—岩土工程]