基于深部位移及气象监测的泥岩滑坡特征及成因分析——以岑溪大业公田滑坡为例

Characteristics and cause analysis of mudstone landslide based on deep displacement and meteorological monitoring: a case study of Gongtian landslide in Daye, Cenxi

为有效监测预警泥岩地区滑坡,找到泥岩地区滑坡的诱发因素,并实现泥岩分布区的防灾减灾,以岑溪大业公田滑坡为例,对滑坡发生前后的现场工程地质勘察及岩矿分析报告进行了分析研究,利用滑动式测斜仪、农田气象监测仪等联合建立了岑溪大业公田滑坡监测系统,对滑坡整个变形过程中的累计位移与深度、位移速率与降雨量等的变化规律进行了分析。结果表明:岑溪大业公田滑坡以浅层多层滑动面滑动为主,地表下1 m处的位移速率与降雨量具有一定相关性,而滑带土的位移速率与降雨量之间具有一定的滞后性;高强度、持续的降雨是滑坡发生的主要诱发因素;岩体破碎、节理裂隙发育、强度低,含有大量亲水性及易溶性矿物的风化泥岩结构是滑坡发生的决定因素;高速公路的建设对坡脚不合理的开削挖及坡面植被的破坏等其他人类工程活动是滑坡发生的影响因素。

In order to effectively monitor and predict the landslide in mudstone area, to find out the inducing factors of mudstone area landslide and the disaster prevention and reduction, this paper studied the landslide of Daye landslide in Cenxi. From the field geological survey before and after the landslide,rock and mineral analysis report, by sliding inclinometer and farmland meteorological monitoring instrument,the landslide monitoring system of Daye landslide is established, through analyzing variation law of accumulative displacement with depth and displacement rate with rainfall during the whole deformation process of landslide. The results show that the landslide in Daye is mainly dominated by shallow multilayer sliding surface.There is a certain correlation between the displacement rate and rainfall at 1 m below the ground surface and a certain lag between the displacement rate of sliding soil and the rainfall. Highly intensity and continuous rainfall is the main inducing factor of landslide.The rock breaking, joint fracture development, low strength, weathered mudstone structure with a large number of hydrophilic and soluble minerals are the decisive factors for the occurrence of landslide. The highway construction is unreasonable by slope cutting surface vegetation destruction.Some human engineering activities are risk factors for landslide.