Analysis of deformation mechanism of landslide in complex geological conditions

This paper describes an interesting landslide located in the mountainous area of Zhejiang Province, China, which was caused by highway construction. Due to the complex geological conditions, the failure mechanism of the landslide is particularly difficult to analyze. The soil deformations were initially judged to be shallow and partial sliding. However, engineering measures used to stabilize the sliding masses failed. By establishing a comprehensive monitoring system composed of GPS, inclinometers and groundwater level monitors, the deformation of landslide was monitored. It is found that the previous deformation mechanism assumed without the monitoring data is incorrect. On the other hand, there is a large rock ancient landslide in the site, and deformation of the soil mass was caused by the reactivation of this ancient landslide. This case study illustrates the importance to deeply analyze the geological data and the field monitoring data and to correctly understand the geological conditions.