碎石土滑坡由于内部含有大量的碎块石,容易形成架空结构,使其内部拥有独特的渗流系统。不同结构的碎石土形成的渗流通道不同,导致滑坡体的失稳情形也各不相同,因此,针对性的防治措施也难于制定。福建省安溪县岩山角落滑坡具有多元结构碎石土滑坡的特征。在对碎石土滑坡进行物探、钻探、水位监测等多重手段整体勘测的基础上,利用SketchUp软件进行建模分析,获取了多元结构碎石土滑坡渗流系统与滑坡物质结构在空间上的关系,并对两类渗流系统的变形敏感性和降雨敏感性进行对比。结果显示,粗石状碎石土区域以集中渗流为主,假斑状碎石土区域以管网状渗流为主,前者对降雨的敏感性较后者高,而受渗流通道的整体强度和渗流稳定性的影响,前者对于滑坡变形的敏感性要低于后者。基于上述分析,确定采用抗滑桩和排水盲沟等工程措施进行治理,根据地下水监测数据和现场验证,治理效果良好,可供其他类似滑坡防治工程提供借鉴与参考。
Gravel soil landslide has a unique internal seepage system, since the soil contains a large number of gravels constituting a matrix structure. Depending on the diversity of gravel soil structures, the network of flow channels can be different and correspondently the landslide pattern is also different. Hence, it is difficult to make the targeted mitigation plans for slope failures. In this study, the case of Yanshanjiaoluo landslide, which is located in Anxi County of Fujian Province, is investigated. The relationship between the seepage system of the gravel soil with multivairiate-structure and the material composition of the landslide is obtained based on the comprehensive geotechnical investigation including geophysical prospecting, drilling, water level monitoring as well as Sketch Up modeling analysis. Comparative analysis is performed to evaluate the deformation and rainfall sensibilities of two sorts of seepage system. The results indicate that the coarse gravel soil area is characterized by concentrated seepage, while the false porphyritic gravel soil area is characterized by pipe network seepage. The former is more sensitive to the rainfall than the latter. However, influenced by the overall strength of the seepage channel and seepage stability, the latter is more sensitive to the deformation of landslide than the former. Based on the above analysis, a combined measure of anti-slide pile and blind drainage ditch is employed to improve the stability of the landslide. The field observation confirms the effectiveness of the mitigating measures.