余震与降雨时序作用下震裂岩体破坏过程模拟方法及失稳力学机制研究

强震作用于山体易形成震裂岩体，在余震、降雨作用下失稳造成的崩塌滑坡危害巨大，其破坏过程模拟方法及失稳力学机制是亟待突破的理论与技术难题。本项目拟基于震裂岩体地质调查与经验认识，紧密依托云南金沙江金安大桥华坪岸坡工程，构建裂隙岩体地质结构模型与地震、降雨力学作用模式，分析余震、降雨下震裂岩体力学性质动态演化规律；以此为基础，集成连续—非连续耦合模型、动力强度准则、接触本构模型、应力渗流耦合与高效并行算法，基于DDA发展模拟岩体从局部裂隙贯通形成块体到整体失稳全过程的方法；结合DDA模拟与模型试验数据，研究裂隙、位移、应力、渗流场演化规律，探讨荷载作用时序效应、应力渗流强耦合效应，形成局部关键块体与整体稳定性协同评价方法，揭示余震—降雨、降雨—余震时序作用下震裂岩体失稳力学机制，从而为震后地质灾害防治提供理论与技术支持，在推动岩体动力学和地质灾害防治学科发展方面发挥积极作用。

Strong earthquakes excitation on mountains can easily lead to shattered rockmass, which will develop to be collapses and landslides under aftershock and rainfall and bring in great harm, and the simulation method and mechanical mechanism are urgent breakthrough in theory and key technical problems. This project based on the geological research and experience on shattered rockmass, focus on Jinan bridge Huaping bank slope of Jinshajiang river, Yunnan. Through building geological structure models and mechanism patterns of earthquake and rainfall of shatter rockmass, dynamic evolutions of shatter rockmass mechanism characteristics under the earthquake and rainfall can be analyzed. Based on the analysis, the continuous-discontinuous coupling models, dynamic strength criterions, contact constitutive models, hydromechanical coupled models and high efficient parallel algorithms are integrated, and the simulation method for the whole crack through process from minor fractures to blocks to lose overall stability can be developed using the discontinuous deformation analysis (DDA) method. Combining the DDA simulations and model test data, the evolutions of fractures, displacements, stress and seepage field are studied; the timing effect of the excitation load, coupling effect of hydromechanical are explored; the approach to collaborative evaluation of minor key blocks and global stability are provided, and the instability mechanical mechanism of the shattered rockmass under the timing excitation of aftershock-rainfall and rainfall-aftershock are revealed. The results can provide theoretical and technical support for geological disaster prevention after the earthquake, and play an important role on promoting the development of rock mass dynamics and geological hazard controlling.