西南某机场高填方边坡滑塌机制分析与处理措施研究

LANDSLIDE MECHANISM AND TREATMENT MEASURES FOR HIGH FILL SLOPE AT AIRPORT IN SOUTHWESTERN CHINA

西南某高填方机场土石方工程竣工后不久遭遇了持续半月的强降水,在一次突发暴雨后4h,边坡发生了滑塌。采用监测、检测、现场调查、原位试验、室内试验、数值模拟等手段进行综合分析。结果认为,该机场高填方边坡滑塌主要是采用含碎石黏性土填筑的土面区、边坡影响区,因强夯补强破坏了填筑体内原有的碎石排水层,造成了采用碎石填筑的道槽区入渗的降水不能及时排出而引发的高地下水压力、渗透变形、浸泡软化等共同作用所致。最后针对性地采取填筑体顶面薄膜覆盖,坡面出水点网装级配碎石反滤和引流、滑塌坡面袋装碎石回填的应急处理措施,以及填筑体顶面黏性土回填、坡面碎石换填、仰斜管排水的永久处理方法,有效地控制了边坡的进一步变形、滑塌,取得了良好的灾害治理效果。

A high fill airport in southwestern China suffered a half month of heavy rainfall immediately after its earthwork has been completed. A landslide occurred at 4 hours after the sudden rainstorm. This paper uses the methods of surveillance, detection, scene investigation, in situ tests, laboratory test and numerical simulation and makes a comprehensive analysis. The slope sliding is due to the following aspects. The embankment of dynamic compaction reinforcement destroyed the original gravel drainage layer in the body of the soil surface area. The affected slope area is the ground with gravel filling of cohesive soil. The rainfall can not be discharged from the channel slot area. High groundwater pressure, seepage deformation, soak softening, and others cause the slide. The emergency measures include film covering the top surface of the filling body, network installation graded gravel filtration and drainage on slope water point, sliding slope gravel bags backfill and permanent disposal method of filling the top of cohesive backfill, slope gravel replacement and yang inclined tube drainage. They effectively control the further slump deformation and slide, achieve good results.