“地质体渐近破坏过程的演化机理及计算模型”2010年度报告

李锡夔　季顺迎　张俊波　刘君　唐洪祥

摘要：本研究“地质体渐进破坏过程的演化机理及计算模型”主要针对工程地质灾害在成形阶段地质体由连续介质向非连续介质的转化特性，建立地质体由既有局部破坏向整体贯穿性破坏的内在机理，并建立相应的判别准则；发展细观与宏观力学参量对应关系的均匀化方法和局部化模型，通过对地质体在灾害成形阶段的宏观细分析，建立内部破坏状态与宏观可测物理量之间的对应关系，并重点研究地质体内部破裂程度与声发射、波动特性及衰减规律、内部滑移与地表位移、地表裂缝之间的对应关系，确定地质灾害发生的前兆信息；发展地质体宏观连续体模型与细观离散体模型相结合的跨尺度计算模型，并开发相应的计算软件。 在2010年度，研究组围绕年度研究计划，主要开展了如下工作，即： 提出了非均质梯度Cosserat连续体的Hill定理；发展了基于细观力学信息的模拟颗粒材料力学响应的离散颗粒集合体-Cosserat连续体的宏观本构模型与细宏观计算均匀化方法；发展了耦合离散单元法和Cosserat连续体有限元法的连接尺度方法；研究了工程地质灾害中岩土颗粒介质的类固-液转化特性及本构模型；发展了岩土材料离散元方法的高性能、大规模数值算法；研究了考虑滚动摩擦的颗粒接触模型和具有破碎解簇功能的非规则颗粒；研究了基于亚塑性/扰动状态模型的土石混合体渐进破坏模拟及颗粒破碎影响；研究了地质体渐进破坏过程及剪切带的发生与演化机理.

关键词：地质体；渐进破坏；演化机理；计算模型

Abstract：The intrinsic mechanisms from existing local failure to global penetrating failure of geological body during the geological disaster are detected considering the transitional characteristics from continuous medium to discrete medium of the geological body. The homogenization method and the localization model will also be developed based on the relationships between micro- and macro- mechanical parameters. With the mechanical analysis of geological body in the forming stage of geological disasters on micro- and macro-scales， the relationship between its internal failure states and the measureable physical parameters will be established. The corresponding relations between the internal breaking degree of geological body and the acoustic emission， the wave features and its attenuation law， between the internal sliding and the surface displacement， the surface cracks will be investigated especially to determine the precursor information of geological disasters. The multi-scale numerical model coupling the macro-continuum model and micro-discrete model of geological body is developed. The relative computational software is developed finally based on the established models above. Following the research scheme of the project in 2010， the research results are obtained as listed below. The Hill theorem was developed with considering the heterogeneous gradient Cosserat continuum theory. The macroscopic constitutive model was developed based on the discrete granular aggregation and the Cosserat continuum. The bridge scale method was developed coupling the discrete element method and Cosserat continuum finite element method. The quasi-solid-liquid phase transition characteristics and its constitutive model were studied for the engineering geological disaster. The computational algorithm was developed for the large scale discrete element simulation with high efficiency for rock-soil materials. The inter-particle contact force model under the influence of rolling friction and the irregular particles with breakage and un-cluster function were investigated comprehensively. The progressive failure of rock-soil mixture was simulated with the hypo-plastic model and the disturbed state model with considering the influence of particle breakage. The compressive failure process of geological body and the generation and evolution of shear band were investigated. Based on the research results above， the research group published 9 journal papers（4SCI and 4EI）.

Keywords：geological body； progressive failure； evolution mechanism； computational model