坡麓相煤系地层斜坡软土滑坡分析与整治研究

Research on the Treatment and Monitoring of Soft Soil Landslide in Piedmont Coal Measure Stratum Slope

研究目的:坡麓相煤系地层斜坡软土具备普通软土的相关特征,且因斜坡地形导致的地表水与地下水积聚、软土组成成分以及下卧基岩面倾斜等不利因素汇聚,与常规沉积型软土相比,自稳性更差。高速铁路路基通过坡麓相煤系地层斜坡软土区域时,易发生边坡坍滑,形成滑坡。本文通过典型案例,研究分析坡麓相煤系地层斜坡软土滑坡成因及整治方案,探究如何减轻甚至避免相关病害。研究结论:(1)斜坡地表覆土封闭层破坏后,地表水迅速渗入炭质页岩全风化层为主并掺杂较多硬质碎、块石的斜坡地层,导致炭质页岩成分吸水饱和软化,强度迅速降低,形成山麓斜坡软土;(2)斜坡软土由炭质页岩软化形成的地质特性和倾斜基岩面是滑坡形成的内因;降雨对地下水形成补给是外因;边坡加载及坡脚卸荷等外因干扰是滑坡形成的直接诱因;(3)滑坡上下游均有环境敏感源时,对上下游敏感源和路基本体分段进行抗滑设计的设计方法更有效;(4)系统化的全过程变形监测必要且有效;(5)本文研究可为坡麓相煤系地层斜坡软土滑坡成因研究及整治技术提供参考。

Research purposes:The slope soft soil of piedmont coal measure strata has the related characteristics of general soft soil,still disadvantages gathering like the accumulation of surface water and groundwater caused by slope topography converge,the composition of soft soil layer,and the inclination of underlying bedrock surface.So the self-stability of slope soft soil is worse than that of conventional sedimentary soft soil.When high-speed railway passes through the soft soil area of piedmont coal measure stratum slope,it is easy to cause slope collapse and landslide.Through a typical case,this paper studies and analyzes the comprehensive treatments of the slope soft soil landslide in the piedmont coal measure strata,and explores how to reduce or even avoid the related diseases.Research conclusions:(1)After the soil cover sealing layer on the slope surface is damaged,the surface water quickly infiltrates into the slope stratum dominated by the completely weathered layer of carbonaceous shale and doped with more hard debris and block stones,resulting in the water absorption saturation softening of carbon shale components,rapid reduction of strength,and the formation of piedmont slope soft soil.(2)The geological characteristics of the slope soft soil formed by the softening of carbonaceous shale and the inclined bedrock surface are the internal causes of landslide formation;Rainfall recharge to groundwater is the external cause;The external force disturbance such as slope loading and toe unloading is the direct cause of landslide formation.(3)When there are environmental sensitive sources in the upper and lower reaches of the landslide,the design method of anti-sliding by sections for the sensitive sources and subgrade is more effective.(4)Systematic whole process deformation monitoring is necessary and effective.(5)The research results can provide reference for the cause research and control technology of slope soft soil landslide in piedmont coal measure strata.