考虑峰值后区应力跌落速率的脆岩损伤本构模型研究  

Study of damage constitutive model of brittle rock considering post-peak stress dropping rate

作　　者：张超 杨期君 曹文贵[2] ZHANG Chao;YANG Qi-jun;CAO Wen-gui(Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University of Science and Technology,Xiangtan,Hunan 411201,China;Geotechnical Engineering Institute,Hunan University,Changsha,Hunan 410082,China)

机构地区：[1]湖南科技大学岩土工程稳定控制与健康检测湖南省重点实验室,湖南湘潭411201 [2]湖南大学岩土工程研究所,湖南长沙410082

出　　处：《岩土力学》2019年第8期3099-3106,共8页Rock and Soil Mechanics

基　　金：湖南省自然科学基金(No.2018JJ3163);湖南科技大学博士启动基金(No.E51858);湖南省教育厅科学研究项目(No.17C0651);岩土工程稳定控制与健康监测湖南省重点实验室开放基金(No.E21707)~~

摘　　要：为了研究和分析脆岩峰值后区变形破坏力学性质,引入统计细观损伤理论,针对以破坏微元体数目与总数目之比定义的损伤变量存在的局限性与不足,在分析非均匀性岩石峰后变形破坏特征基础上探讨脆岩细观损伤演化机制,建立了考虑破坏微元体引起岩石材料非均匀性的修正损伤模型,并提出模型修正系数的函数假设;然后,在此基础上推导建立了岩石修正统计损伤本构模型,并给出了模型参数的确定方法;最后,将模型理论曲线与试验曲线进行了比较分析,并对模型参数的变化规律进行了讨论。研究表明:该模型能够反映脆岩峰值后区不同应力跌落速率的现象,模型理论曲线及模型参数的变化规律与试验结果较为吻合,表明提出的模型和方法具有一定的合理性与可行性。In this paper,the statistical meso-damage theory was introduced to study the deformation and failure mechanical properties of brittle rock in the post-peak region.The limitations and the deficiencies of the damage variables defined by the ratio of the damaged miro-element number to the total number were discussed.The meso-damage evolution mechanism of brittle rock was analysed based on the post-peak deformation and failure characteristics of the heterogeneous rock.The modified damage model was established considering the non-uniformity of the rock material caused by the damaged micro-element.Meanwhile,the function hypothesis of the modified model coefficient was proposed.Then,based on this,the modified statistical damage constitutive model of rock was established,and the methods of determining the model parameters were given.Finally,the theoretical curves of this model were compared with the experimental curves,and the variation law of the model parameters was discussed.The research shows that this model can reflect the different stress dropping rate of brittle rock in the post-peak region.The theoretical curve and variation law of the model parameters are in good agreement with the experimental results,which indicates that the proposed model and methods have certain rationality and feasibility.

关 键 词：脆岩 应力跌落速率 非均匀性 损伤 本构模型 

分 类 号：TU452[建筑科学—岩土工程]