南宁环城高速公路K18路堑滑坡形成机制与综合处治对策

The Formation Mechanism and Comprehensive Engineering Treatment of Cutting Slope Landslide at K18 Section of Expressway around Nanning

滑坡是南宁盆地高等级公路建设和营运中的主要地质灾害之一,运用工程勘察与数值计算等手段研究了南宁环城高速公路K18路堑滑坡的岩土工程地质特征、形成机制和稳定性。研究表明:该边坡属不良地质结构的顺层折线中型滑坡,主要诱发原因为强降雨入渗和路基开挖;在饱和状态下,稳定性系数平均为0.88,属于不稳定边坡,危及公路的安全。针对滑坡特点和工程环境条件,研究应用以锚拉桩+预应力锚索轻型支挡结构为主,辅以排水、绿化的综合原位处治工程措施。实践证明,该处治对策具有安全可靠、保护环境、节约投资和加快施工进度等优点,治理费用比传统单一技术措施节约30%,对南宁盆地类似滑坡地质灾害勘察与治理具有参考价值。

Landslide is one kind of main geological disasters of freeway construction and operation in Nanning-Basin.The geotechnical engineering geologic characteristics, failure mechanism and stability of the cutting slope landslide at k18 section of expressway around Nanning are studied by exploration and numerical calculation method. It shows that the formation of the landslide is caused by the landform and its special geological construction of around rock, engineering excavation and precipitation. The average stability coefficient of the cutting slope is 0.88 at the state of saturation. It is unstable and dangerous to expressway operation. According to the landslide characteristics and engineering environment, the comprehensive engineering in-situ measures such as anchorage pile plus prestressed anchor cables, drainage, planting and so on are presented. Compared with traditional single slope protection technology, the treatment method has many advantages such as safety, environmental protection, quick construction, and 30% cost saving.The experience is of significance to investigation and engineering treatment for landslide geologic disaster in Nanning-Basin.