岩石弹塑性损伤本构模型建立及在隧道工程中的应用  

An elastoplastic damage constitutive model of rock and its application to tunnel engineering

作　　者：王军祥[1,2] 姜谙男[1,2] 

机构地区：[1]大连海事大学道路与桥梁工程研究所,辽宁大连116026 [2]大连海事大学辽宁省公路工程重点实验室,辽宁大连116026

出　　处：《岩土力学》2015年第4期1147-1158,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51079010);中央高校基本科研业务费专项资金项目(No.2013YB03;No.3132013315);大连市交通科技项目(No.2011-10);吉林省交通厅交通运输科技项目(No.2012-1-6)

摘　　要：在实际隧道施工过程中,隧道开挖引起地下岩体应力重分布使得围岩的微裂纹扩展损伤,并伴随有塑性流动变形。在地下水环境中对于孔隙和微裂隙围岩介质受到应力作用时,在内部将产生高孔隙水压力影响岩石的力学性质,也改变了围岩的破坏模式。为了研究损伤引起的刚度退化和塑性导致的流动两种破坏机制的耦合作用,从弹塑性力学和损伤理论的角度出发,同时引入修正有效应力原理来考虑孔隙水压力的作用,建立基于Drucker-Prager屈服准则的弹塑性损伤本构模型;针对该本构模型推导了孔隙水压力作用下弹塑性损伤本构模型的数值积分算法-隐式返回映射算法,分别对预测应力返回到屈服面的光滑圆锥面或尖点奇异处两种可能的情况给出了详细的描述,隐式返回映射算法具有稳定性和准确性的特点;大多数弹塑性损伤模型中涉及参数多且不易确定的问题,采用反分析方法获得损伤参数,解决了损伤参数不易确定的难题;采用面向对象的编程方法,使用C++语言编制了弹塑性损伤本构求解程序,并对所建立的弹塑性损伤模型和所编程序进行了试验和数值两个方面的验证;最后将其在吉林抚松隧道工程中进行应用,模拟了塑性区和损伤区的发展变化。研究结果表明:所建立的弹塑性损伤本构模型能够较好地描述岩石的力学性能、塑性和损伤变化趋势,所编程序能够进行实际工程问题的模拟,对现场施工给予一定的指导。In practical tunnel construction, the stress redistribution of underground rocks caused by tunneling usually leads to microcrack-expansion damage in the surrounding rock, with accompanied plastic flow deformation. The high pore water pressure is generated in the pores of rock and microcracks under stressed conditions in groundwater environment, which in turn influences the mechanical properties and the changes of the failure modes of the surrounding rock. To investigate the coupling effect of two types of failure mechanisms which are the damage-induced stiffness degradation and the plasticity-driven flow. based on the elastoplastic and damage theories, the modified effective stress principle is adopted to consider the effects of pore water pressure, and then an elastoplastic damage constitutive model is developed adopting the Drucker-Prager yield criterion. To implement this model, a numerical integration algorithm-implicit return mapping algorithm is developed with considering the effect of pore water pressure,and the detail descriptions of the implicit return mapping algorithm about the trial stress returning to the smooth cone surface or sharp point singularity on the yield surface are given. The implicit return mapping algorithm has good performance with regard to stability and accuracy. The set of parameters related to elastoplastic damage models is large and not easily determined. To resolve this issue, a back analysis method is introduced. The elastoplastic damage constitutive model is implemented by adopting the method ofobject-oriented programming using C＋＋ language. The proposed model and the computational procedure are validated by comparing the numerical simulations to the experimental measurements. The proposed procedure is applied to Jilin Fusong tunnel project to analyze the development of the plastic zone and the damage zone. The results show that the proposed elastoplastic damage constitutive model can well describe the mechanical behavior of the rock, and the computational procedure can simu

关 键 词：孔隙水压力 弹塑性损伤本构模型 修正有效应力原理 Drucker-Prager屈服准则 隐式返回映射算法 反分析方法 

分 类 号：TU452[建筑科学—岩土工程]