考虑非贯通节理损伤演化岩体复合本构模型  

Compound constitutive model considering damage evolution of non-persistent fractured rock mass

作　　者：李列列[1,2] 肖明砾[1,2] 卓莉[1,2] 袁泉[3] 何江达[1,2] 

机构地区：[1]四川大学水利水电学院,成都610065 [2]水力学与山区河流开发保护国家重点实验室(四川大学),成都610065 [3]四川省交通运输厅公路规划勘察设计研究院,成都610065

出　　处：《哈尔滨工业大学学报》2017年第6期96-101,共6页Journal of Harbin Institute of Technology

基　　金：国家重点基础研究发展计划(2015CB057903)

摘　　要：非贯通节理岩体的力学特征与完整岩石相比有较大差异.为推导非贯通节理岩体在单轴压缩下的复合损伤本构模型,采用修正自洽方法考虑不同损伤变量之间的复合.从附加应变能增量和损伤应变能释放量相关联的思路出发,采用等效直线裂纹作为节理裂隙损伤演化轨迹,分别计算细观损伤、初始节理和节理裂隙损伤演化引起的附加应变能;基于Betti能量互易定理,引入自洽方法考虑节理裂隙之间的相互作用,并采用逐条添加节理的方法对传统自洽方法进行修正,得出岩体不同受力阶段细观、初始节理和节理裂隙损伤演化的复合损伤本构模型;将本构模型的理论计算结果与现有文献的室内试验结果进行对比分析,结果显示:本构模型的理论计算结果与室内试验结果规律一致,随着节理个数增加,初始弹性模量和荷载峰值均呈下降趋势,下降幅度较为一致;节理裂隙的损伤演化对岩体的力学特性有重要影响,考虑节理裂隙损伤演化的理论应力应变曲线和荷载峰值与室内试验结果更为吻合,有效验证了复合损伤本构模型的正确性与合理性.Comparing with intact rock, the mechanical characteristics of non-persistent closed jointed rock mass have relatively large differences.A revised self-consistent method was used to consider the coupling between different damages, as a result, the compound constitutive model was deduced for non-persistent closed jointed rock mass under uniaxial compression.Based on the correlation between additional strain energy increment and damage strain energy release, the equivalent linear crack as jointed crack damage evolution trajectories was adopted, and then the additional strain energy for micromechanical damage, initial joints and jointed crack damage evolution was respectively calculated.In accordance to the Betti energy reciprocity theorem, a self-consistent method was introduced to account for the correlation among cracks, moreover, an approach for adding joints one by one was utilized to correct the traditional self-consistent method, in which the compound damage constitutive model was deduced in regard to different stages during uniaxial compression.The theoretical calculation results of the proposed model were compared with in-house experimental results in existing literature.The results show that： the theoretical calculation results are consistent with the experimental results.With the increase the number of joints, the initial elastic modulus and peak load show a downward trend, and the reducing value is in the same extent;there are significant impacts for the damage evolution of joints crack damage on the mechanical characteristics of the rock mass.The theoretical stress-strain curve and peak load for joint fissure damage evolution are consistent with in-house experimental results, which apparently verify the correctness and reasonability of the compound damage constitutive model.

关 键 词：非贯通闭合节理 损伤 演化 复合 本构模型 单轴压缩 

分 类 号：TU45[建筑科学—岩土工程]