四川省盐源玻璃村特大型玄武岩古滑坡复活机制

受前期14 d持续累计350.6 mm降雨影响，2018年7月19日盐源玻璃村一巨型玄武岩古滑坡体发生大规模复活，复活体积为1 390×104 m3，损坏房屋186间，造成重大经济损失。基于现场调查、无人机航测、钻探揭露、物理力学试验及数值模拟分析，在查明滑坡体地质结构、失稳特征基础上，对其影响因素及复活机制进行了探讨。研究结果表明，破碎岩土体及地形地貌是滑坡复活的孕灾基础，持续降雨及其引起的地下水位升高是滑坡复活的诱发因素。复活滑坡可分为主滑区和侧滑区两种破坏模式不同的区域。降雨作用下滑坡体内渗流场明显变化，孔隙水压力增大，导致7月13日古滑坡体开始发生变形，稳定性系数逐渐降低。受微地貌约束，主滑区具有多级、多次失稳，渐进破坏的特点。侧滑区斜坡前缘临空条件受坡脚主滑坡控制，在主滑坡运动过程中，侧滑区坡体位移量、最大剪切应变增量逐渐增大，塑性区扩展，破坏过程表现出与主滑坡一定的关联性和滞后性。分析表明，受地下水长期影响，滑带土体强度逐渐削弱，降雨导致坡体渗流作用加剧，抗剪强度降低，从而诱发滑坡复活。

The reactivated mechanism of Boli Village giant ancient basalt landslide in Yanyuan,Sichuan

Influenced by the continuous cumulative rainfall of 350.6 mm in the previous 14 days, a large-scale reactivation of a giant basalt ancient landslide in Yanyuan Boli Village occurred on July 19, 2018. The resurrected volume was 1 390×104 m3 and 186 houses were damaged, causing significant economic losses. Based on field investigation, aerial survey of drone, drilling, physical and mechanical experiments, and numerical simulation, the factors and reactivated mechanism of the landslide were identified on the basis of geological structure and characteristics of the landslide. The results show that fractured rock-soil mass and topography are the fundamental causes for reactivation, and continuous rainfall and the rising of groundwater level are the triggering factors of reactivation. The landslide can be divided into two areas with different failure modes: main slide area and lateral collapse area. The seepage field in the landslide has significantly changed due to rainfall, and the pore water pressure has increased. As a result, the ancient landslide began to deform on July 13, and the stability factor gradually decreased. Constrained by microtopography, the main slide area is characterized by multiple stages and retrogressive failure. The front edge of the lateral slope is controlled by the main slide at the toe of the slope. During the movement of the main slide, the slope displacement and maximum shear strain increment in the lateral collapse area gradually increase, and the plastic zone expands, showing a certain relevance and lag with the main slide. This analysis indicates that due to the long-term influence of groundwater, the strength of the sliding mass gradually weakens. Rainfall leads to intensification of slope seepage and a decrease in shear strength, which induces landslide reactivation.