明溪烽林场滑坡形成机理及防治措施

明溪烽林场滑坡是福建省少见的缓倾角土质滑坡,滑坡位于丘陵小盆地的腹地,处于沉积碎屑岩与侵入岩接触带上,场地坡度较平缓,作为烽林场建设用地后,对场地进行了全面改造,在强降雨作用下诱发滑坡.后缘大量弃土堆载、前缘过度开挖为滑坡形成创造了良好的条件,接触带附近常年地下水排泄区沉积了厚度较大的有机质土隔水层,地下水具有承压性质,在强降雨作用下,后缘填土在自重及静水压力作用下失稳变形,并向中部及前缘产生强大的推力,中、前缘土体在推力及地下扬压力水顶托下,产生鼓胀变形,形成较明显的推移式滑坡特征.分析了滑坡变形特征,对滑坡成因及形成机理进行了探讨,在此基础上,提出科学合理的治理工程措施,治理工程完成近3年来,取得了良好的效果.

The formation mechanism and control measures of Fenglinchang landslide in Mingxi county

Mingxi Fenglinchang landslide is a rare gently inclined soil landslide in Fujian Province. The landslide is located in a small basin hinterland and in the deposition of clastic rocks and intrusive contact zone. The site of the landslide has a gentler slope, and after a comprehensive transformation as the construction land for Fenglin farm, it is formed under the strong the action of rainfall. A large amount of waste heap load and over-excavation have created favorable conditions for the formation of the landslide near the contact zone. Perennial groundwater discharge area deposited thick organic soil aquiclude and because the groundwater is pressure-bearing, after strong rainfall, the filling deformed under self weight and instable static water pressure, and created a strong thrust to the middle and front. The soil in the middle and the front bulged and deformed under the thrust and the uplift pressure from the underground water, forming a more obvious lapsed landslide feature. This paper analyzes the characteristics of landslide deformation, and forming mechanism of landslides, and on this basis, puts forward scientific and rational measures of project management. It is proved that the projects have achieved good results in the past 3 years.