南京下蜀土滑坡灾变成因现场调查及加固处理措施

Field investigation and reinforcement treatment measures of typical Xiashu soil landslide

2017年5月25日,南京市红枫路衡阳排灌站西侧一典型下蜀土在降雨以及地下水渗流作用下,局部发生了滑坡,在地质灾害勘察治理中以该滑坡(HP1和HP2)为研究对象,通过无人机航拍、裂缝量测、边坡位移监测等现场调查手段,分析了滑坡的基本特征、边界条件、影响滑坡稳定性的因素及滑坡的滑移模式,发现强降雨导致土体饱和,重度增加,抗剪强度降低是产生滑坡的直接原因。结合边坡初次滑动后的坡体持续性位移监测数据,采用Bishop法作为主要的计算方法,瑞典条分法和M-P法作为参考,复核了滑坡在自重工况和暴雨工况下的稳定系数,并依据Bishop法得到滑坡的设计推力,采用抗滑桩为主要支护手段对滑坡进行综合治理,使滑坡的安全系数满足设计值,可使滑坡处于稳定状态。

Taking the typical Xiashu soil landslide in Nanjing as research object,field investigation means such as UAV aerial photograph,crack measurement and slope displacement monitoring,the basic characteristics,boundary conditions,influence factors,and slide modes for the landslide are analyzed.It is found that heavy rainfall leads to soil saturation,severe increase,and the decrease of shear strength is the direct cause of the landslide.With the continuous displacement monitoring of slope body after the initial sliding,the calculation methods,such as Bishop method,Sweden method and M-P method,are used to evaluate the slope stability.The stability factor of the slope under natural and rainstorm condition are obtained.The design trusts of landslide are obtained based on Bishop method.The anti-slide pile is considered as reinforcement measure to reinforce the landslide.The stability factor of the reinforced landside meets to design value of code and the slope is in stability state.