近断层地震动作用下岩体结构面强度劣化机理研究

随着国家“一带一路”和交通强国战略的推进，以川藏铁路等为代表一大批重点工程建设在西部强震山区逐步开展。岩体结构的稳定性是制约强震山区工程建设的关键问题，其背后的科学问题是强震作用下的岩体结构面失稳。当前关于结构面地震劣化的研究大多集中于循环荷载对结构面强度的影响规律，而对于往往更具破坏力的近断层脉冲荷载则少有涉及，也未探明考虑近断层地震动脉冲特征的结构面劣化机理。针对这一问题，本项目拟以近断层脉冲特性对岩体结构面强度的影响为切入点，探究近断层地震动作用下岩体结构面强度劣化规律。本项目拟通过现场调查、室内试验、理论分析和数值模拟相结合的方法，对典型岩体工程结构面进行调查取样，研究不同近断层地震动作用下结构面强度变化规律，得到岩体结构面强度劣化准则，开发扩展的非连续变形分析程序并对近断层岩体结构渐进破坏过程进行分析，为强震山区岩体工程稳定性评价和防护设计提供科学依据。

The stability of near-fault rock mass structure is a key problem which restricted engineering construction in earthquake-prone mountainous area. The science challenge behind this problem is the strength degradation rules of the structure plane under near-fault pulse-like ground motion (PLGM). Currently, the research of the strength degradation rules mainly focuses on the cyclic loading situation. However, the near-fault PLGM, which is usually more destructive, is rarely studied. The pulse characteristics is also not included in the strength degradation mechanism of the structure plane. Based on this fact, this project aims to investigate the effect of near-fault PLGM characteristics on rock structure degradation and tries to propose the degradation rules of the structure degradation under near-fault PLGM. This project use in-situ investigation, laboratory experiment and numerical simulation to record the structure plane data, study the strength changing pattern of the structure plane under near-fault PLGMs and obtain the strength degradation rules. A discontinuous deformation analysis method incorporating such strength degradation rules will also be developed to provide scientific evidence about stability and protection design of rock mass structures in mountainous area under strong earthquakes.