考虑拉破坏的黏土边坡地震稳定性评价方法研究

Landslides triggered by earthquake is a common secondary geological disaster, and our country is one of the seismic high-risk countries in the world. Therefore, how to evaluate the slope stability under the earthquake scientifically and efficiently has become an urgent problem to be studied. Aiming at the clay slope seismic stability, the work are carried out based on the numerical simulation method, combined with the results of the related experiments and the field survey. On the one hand, the tensile failure mechanism of the clay slope under the action of earthquake is discussed, and the law of formation and development between the tensile failure and the shear failure is revealed. On the other hand, from the cumulative effect of earthquake, the relationship between the penetration degree of the equivalent plastic strain zone in the slope and the stability of the slope body is analyzed. Finally, the seismic stability evaluation method of the clay slope considering tensile failure is established, which can provide theoretical basis and technical support for the seismic design of slope engineering and emergency rescue after disaster.

地震触发滑坡是一种常见的次生地质灾害，而我国又是世界上地震高风险国家之一，因此，如何能科学、高效地评价震后边坡稳定性成为了一个亟待需要研究的问题。本申请针对黏土坡的震后稳定性这一课题，基于数值模拟方法，结合相关试验和实地调查的成果资料，一方面探讨地震作用下黏土坡的拉破坏机制，揭示拉破坏与剪破坏破裂面之间的形成和发展规律，另一方面从地震的累积效应出发，分析坡体内等效塑性应变区贯通程度与坡体稳定性的关系，建立考虑拉破坏的黏土坡地震稳定性的评价方法。研究成果可为边坡工程抗震设计和灾后应急救援等提供理论依据和技术支撑。

相对降雨等其他非短暂的动力作用，土坡在地震作用下，坡肩受到的张拉破坏更为明显，其破坏演变机制也有所不同。本研究以西南地区的土质边坡为对象，对不同高度和坡度的边坡开展模拟分析，研究了土坡在地震作用下的张拉-剪切破坏演变过程，揭示了破裂面形成及发展机制，总结了地震作用下土坡破裂面的基本模式；从地震的累积效应的角度建立了地震作用下土坡失稳的判断依据，结合塑性应变和位移变化建立土坡地震失稳判据，并探讨了其在考虑拉破坏也即张拉-剪切破坏模式下的适用性，进一步提出考虑张拉破坏效应的土坡地震稳定性评价方法。本研究课题共发表和录用相关学术论文 6篇（其中SCI收录3篇，中文核心收录2篇，普通学报1篇），培养研究生3名。项目研究结果可为土坡在震前抗震设防以及震后稳定性评价提供理论依据和技术支持。