Based on the Drilling and High-density Resistivity Method to Research Landslide in the Permafrost Regions

Abstract

In recent years, permafrost in north-eastern part of China is being severely degraded. Bei’an to Heihe expressway passed through the north-western part of the Lesser Khingan Range region. Stability of embankment in this region is being seriously affected landslide occurrence and the degradation of permafrosts. The expressway utilizes the original second-class highway to widen and expand, being restricted by the original location of the old road, some sections of new sub-grade are located at the toe of the landslides. The formation and development of the landslide at K178+530 section of the expressway is mainly affected by the topography, engineering geology, hydrology and climatic influences. Topography, loose stratum, active groundwater, intense freeze–thaw erosion and human engineering activities are inherent conditions and contributing factors affecting the stability of the slope. In order to study and analyze the landslide, geological drilling exploration and high-density resistivity method were employed to understand the failure mechanism of the landslide along the expressway. The results show that high-density resistivity technology and drilling exploration gave similar result near the landslide sliding surface; there is a significant difference between inside and outside the landslide soil resistivity values. When the landslide had not yet formed, the landslide resistivity value had no obvious stratification, and had no saltation phenomenon of the resistivity. After the landslide began to move, the resistivity value at the sliding surface location showed significant stratification, and the resistivity values of its upper and lower location were obviously different.