考虑围压效应和强度脆性跌落的岩石全应力-应变曲线统计损伤模拟方法  

Statistical damage simulation method for complete stress-strain path of rocks considering confining pressure effect and strength brittle drop

作　　者：张超 曹文贵[2] 赵衡[2] 贺敏 ZHANG Chao;CAO Wen-gui;ZHAO Heng;HE Min(Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University of Science and Technology,Xiangtan 411201,China;Geotechnical Engineering Institute of Hunan University,Changsha 410082,China;College of Civil Engineering,Hunan University of Technology,Zhuzhou 412007,China)

机构地区：[1]湖南科技大学岩土工程稳定控制与健康监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 [3]湖南工业大学土木工程学院,湖南株洲412007

出　　处：《岩土工程学报》2022年第5期936-944,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51909086);湖南省自然科学基金项目(2018JJ3163,2020JJ5131);湖南省教育厅科学研究项目(21B0489,18C0505)。

摘　　要：为了建立能够较准确地描述岩石全应力-应变曲线的统计损伤模拟方法,针对目前统计损伤本构模型在模拟围压效应和强度脆性跌落方面存在的严重缺陷,首先,基于三轴压缩条件下脆性岩石基本变形特征,将岩石视为由软物质和硬物质两种细观化材料串联组成,建立宏细观物质变形分析模型;然后,基于瞬时应变分析方法和统计损伤理论,分别提出软物质和硬物质的变形分析方法,从而建立能够考虑围压效应和强度脆性跌落的岩石全应力-应变曲线统计损伤本构模型,给出参数的确定方法;最后,通过模型验证与分析,模型不但能够描述岩石初始宏观变形特征与围压之间的关系,也能够消除岩石轴向峰后理论变形曲线存在的随机性,从而能够较准确地模拟出岩石全应力-应变曲线,表明方法具有一定的合理性和可行性。To establish a statistical damage simulation method which can accurately describe the full stress-strain curve of rocks,aiming at the serious defects of the existing statistical damage constitutive models in simulating confining pressure effect and strength brittle drop, firstly, based on the basic deformation characteristics of brittle rocks under triaxial compression, the rocks are regarded as a series of two meso-materials: soft and hard materials, and the deformation analysis model for macro-and meso-materials is established. Then, based on the instantaneous strain analysis method and statistical damage theory, the deformation analysis methods for the soft and hard materials are proposed respectively, so as to establish the statistical damage constitutive model for the full stress-strain curve of rocks considering confining pressure effect and strength brittle drop, and the determination methods for the model parameters are given. Finally, through model verification and analysis, the proposed model can describe the relationship between the initial macro-deformation characteristics of rocks and the confining pressure and eliminate the randomness of the axial post-peak theoretical deformation curve, so it can accurately simulate the full stress-strain curve of rocks, which shows that the above methods are reasonable and feasible.

关 键 词：脆性岩石 统计损伤 围压效应 强度脆性跌落 全应力-应变曲线 

分 类 号：TU452[建筑科学—岩土工程]