近断层脉冲地震动作用下岩质滑坡剧动失稳及多重加速机理研究

With the booming development of infrastructure construction in the high intensity mountain area of China, more and more seismic geological hazards issues need to be taken seriously. Since the earthquake-induced landslides are mainly distributed in the near-fault area and along the direction of pulse-like ground motion, the near-fault pulse-like ground motion plays an important role in the initiation and run-out of earthquake-induced landslides. However, the near-fault earthquake loadings have not been seriously considered in the study of earthquake-induced landslides. The objective of this project tries to clarify the rapid failure and multiple acceleration mechanism of rock landslides induced by near-fault pulse-like ground motion through rigorous dynamic block theoretical analysis, serial shaking table tests and sophisticated DDA numerical simulation after establishing databases of near-fault ground motion and earthquake-induced landslide. The purpose of the study is to propose a permanent displacement prediction model of earthquake-induced landslides considering the influence of near-fault pulse-like ground motion, to find out the main controlling factors of rapid failure of rock landslide induced by near-fault seismic loading, to present a multiple acceleration model and verify its accuracy, to perform a multi-scale numerical modelling for the whole process of rock landslides when subjected to complex near-fault earthquake loadings, and eventually reveal the rapid failure and multiple acceleration mechanism of rock landslides induced by near-fault pulse-like ground motion. This study will certainly present deep exploration in the intrinsic mechanism of the earthquake-induced landslides. In addition, it will provide fundamentals for the development of disaster prevention and mitigation system in the construction of high-profile engineering projects and the planning of Urban-Rural in high intensity mountain area.

根据我国基础建设不断深入高烈度山区面临的地震地质灾害防控需求，本项目基于地震滑坡的近断层分布规律及沿脉冲地震动优势方向展布的事实，针对当前地震滑坡研究中近断层脉冲地震动作用下岩质滑坡失稳及加速机理不明的现状，在建立近断层地震动记录和地震滑坡数据库的基础上，通过准确的动力块体理论分析、系列的振动台模型试验和精细的DDA数值模拟，对近断层脉冲地震动作用下岩质滑坡剧动失稳及多重加速机理进行研究。以期建立近断层地震滑坡永久位移的预测模型；确定导致近断层岩质滑坡剧动失稳的主控因素；提出并验证近断层脉冲地震动作用下岩质滑坡多重加速模型；实现复杂近断层脉冲地震动作用下岩质滑坡的大尺度全过程数值模拟，最终揭示近断层脉冲地震动作用下岩质滑坡剧动失稳及多重加速机理。项目成果不仅对揭示地震滑坡机理具有重要的科学意义，也可为解决高烈度山区重大线路工程选线和城乡规划中面临的地震滑坡防灾减灾问题提供科学依据。

针对当前地震滑坡研究中近断层脉冲地震动作用下岩质滑坡失稳及加速机理不明的现状，在建立近断层地震动记录和地震滑坡数据库的基础上，通过准确的动力块体理论分析、系列的振动台模型试验和精细的DDA数值模拟，对近断层脉冲地震动作用下岩质滑坡剧动失稳及多重加速机理进行研究，建立了近断层地震滑坡永久位移的预测模型；确定了导致近断层岩质滑坡剧动失稳的主控因素；提出并验证了近断层脉冲地震动作用下岩质滑坡多重加速模型；实现了复杂近断层脉冲地震动作用下岩质滑坡的大尺度全过程数值模拟，最终揭示了近断层脉冲地震动作用下岩质滑坡剧动失稳及多重加速机理。.通过数据收集、现场调查、理论分析、数值模拟和模型试验，从失稳机理、灾害评价和抗震技术三个方面开展了系统研究，①建立了数据量最大的地震滑坡灾害数据库，揭示了高陡边坡地震脉冲致滑机理；②提出了基于裂纹扩展和粗糙度衰减的高陡边坡连续-非连续灾变全程模拟方法，实现了边坡震灾定量评价；③开发了理论分析与数值模拟相结合的地震滑坡危险源识别技术及高陡边坡地震安全防护技术。项目成果不仅对揭示地震滑坡机理具有重要的科学意义，也可为解决高烈度山区重大线路工程选线和城乡规划中面临的地震滑坡防灾减灾问题提供科学依据。