“地質體漸近破壞過程的演化機理及計算模型”2010年度報告

李錫夔　季順迎　張俊波　劉君　唐洪祥

摘要：本研究“地質體漸進破壞過程的演化機理及計算模型”主要針對工程地質災害在成形階段地質體由連續介質向非連續介質的轉化特性，建立地質體由既有局部破壞向整體貫穿性破壞的內在機理，并建立相應的判別準則；發展細觀與宏觀力學參量對應關系的均勻化方法和局部化模型，通過對地質體在災害成形階段的宏觀細分析，建立內部破壞狀態與宏觀可測物理量之間的對應關系，并重點研究地質體內部破裂程度與聲發射、波動特性及衰減規律、內部滑移與地表位移、地表裂縫之間的對應關系，確定地質災害發生的前兆信息；發展地質體宏觀連續體模型與細觀離散體模型相結合的跨尺度計算模型，并開發相應的計算軟件。 在2010年度，研究組圍繞年度研究計劃，主要開展了如下工作，即： 提出了非均質梯度Cosserat連續體的Hill定理；發展了基于細觀力學信息的模擬顆粒材料力學響應的離散顆粒集合體-Cosserat連續體的宏觀本構模型與細宏觀計算均勻化方法；發展了耦合離散單元法和Cosserat連續體有限元法的連接尺度方法；研究了工程地質災害中巖土顆粒介質的類固-液轉化特性及本構模型；發展了巖土材料離散元方法的高性能、大規模數值算法；研究了考慮滾動摩擦的顆粒接觸模型和具有破碎解簇功能的非規則顆粒；研究了基于亞塑性/擾動狀態模型的土石混合體漸進破壞模擬及顆粒破碎影響；研究了地質體漸進破壞過程及剪切帶的發生與演化機理.

關鍵詞：地質體；漸進破壞；演化機理；計算模型

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