Second International Conference on Advances In Civil, Structural and Environmental Engineering- ACSEE 2014
Author(s) : WEI SHAN, ZHAOGUANG HU
In recent years, permafrost in the northeast of China is being severely degraded. Bei’an-Heihe Expressway crosses northwest part of the Lesser Khingan Range region. The landslide is located in an area of the island’s permafrost. Due to atmospheric precipitation, the presence of permafrost, regional climate conditions, and special geological conditions, landslides occur annually from late May to early November. The area is in a relatively stable state during winter. These seasonal landslides have seasonal, gradual, low angle characteristics. By January 2014, the landslide had moved a distance of up to 113.32 m (in the rear), and 26.4 m (at the leading edge). With cumulose soil at rear of landslide decreasing, and the recorded movement of the landslide over time, the landslide deformation appears to show an apparent attenuation trend. This article combines a geological survey and over three years of monitoring surface deformation. Research results show that: water infiltration of rainfall, melting snow and permafrost melting is stopped by frozen soil and impermeable barriers, leading to local moisture content rapidly rising, water erosion along interface between the permeable layer and water-resisting layer forms the sliding surface. Sliding velocity of the landslide is large different in different seasons. Within the same cross section of landslide, the sliding displacement of center is largest, and near landslide flank is smallest.