地震纵波作用下节理岩体宏观动力响应及其细观机制研究

According to the intense development of landslides and avalanches in the region of "Peng-guan complex" along Minjiang Rive, considering the controlling factor of seismic P-wave in the initial deformation-failure process of rock masses near the epicenter, the deformation-failure mechanisms of jointed rock masses under P-waves will be studied. Through detailed field geological investigation and the analysis of relevant geological data, the geological conditions of earthquake engineering of the landslides and avalanches for jointed rock slope and the controlling factor during the process of its failure and deformation would be studied. The indoor low cycle tension-compression fatigue tests of and the particle flow numerical simulation technology will be applied to analyze the initial deformation and failure characteristics and mesoscopic structure dynamics of jointed rock mass under seismic P-wave from both the macro and meso-level. And the macro dynamic response characteristics and the mesoscopic mechanism of jointed rock mass under the tension-compression cyclic loading under seismic P-wave will be revealed. Then the initial deformation and failure characteristics of jointed rock slope under seismic P-wave will be explored and the initial damage state and failure mode of jointed rock mass under seismic P-wave will be built. The outputs are expected to promote the research process of jointed rock mass destruction, further improve and enhance the research level of theory and technology of earthquake-induced geological hazards and provide technical support for the prevention and forecasting of avalanches and landslides disaster in the macro-epicenter area.

针对汶川地震期间岷江两岸彭灌杂岩区崩滑灾害密集发育的现象，考虑震中附近地震纵波对岩体初期变形破坏的主控作用，开展地震纵波诱发节理岩体岩体变形破裂机制研究。通过野外地质详查和相关资料分析，研究节理岩质斜坡崩滑灾害形成的地震工程地质条件及其失稳变形的主控因素；采用室内低周拉压疲劳试验手段，并结合颗粒流数值仿真技术等技术方法，从宏观和细观两个层面分析地震纵波引起节理岩体发生初期变形破坏的特征、规律及其细观结构动力学特性，揭示在地震纵波拉压循环荷载作用下节理岩体试样的宏观动力响应特征及其细观机制；探索节理岩质斜坡在地震纵波作用下的初期变形破坏特征与规律，初步建立在地震纵波作用下的节理岩体初始破坏状态和失稳模式。预期成果有望推动节理岩体失稳破坏的研究进程，进一步完善和提高地震地质灾害研究的理论与技术水平，为宏观震中区节理岩质斜坡失稳预测和防治提供技术支撑，具有一定的科学与现实意义。

本项目针对汶川地震期间岷江两岸彭灌杂岩区崩滑灾害密集发育的现象，考虑震中附近地震纵波对岩体初期变形破坏的主控作用，开展地震纵波诱发节理岩体变形破裂机制研究。通过野外地质详查和相关资料分析，研究节理岩质斜坡崩滑灾害形成的地震工程地质条件及其失稳变形的主控因素；采用室内低周疲劳试验手段，并结合颗粒流数值仿真技术等技术方法，从宏观和细观两个层面分析地震纵波引起节理岩体发生初期变形破坏的特征、规律及其细观结构动力学特性。研究内容包括(1)节理岩体崩滑灾害的地震工程条件分析;(2) 节理岩体动力学特性试验研究;(3) 节理岩体细观破裂机制研究;(4) 节理岩质斜坡变形破坏机理; (5)节理岩质斜坡典型失稳模式研究.本项目研究关注了震时岩石或岩体本身发生的变化，也即关注岩体细观层面的变形破坏，进而深入剖析强震动下节理化岩体成灾机理，从宏观和细观两个层面进行了剖析。基于室内试验，借助数值仿真技术，实现了由试件尺度到坡体尺度的研究。.上述研究成果基本实现了本项目的各项计划研究目标，预期成果有望推动节理岩体失稳破坏的研究进程，为宏观震中区节理岩质斜坡失稳预测和防治提供技术支撑，具有一定的科学与现实意义。