ANALYSIS ON THE STRUCTURE CHARACTERISTICS OF A UNDERLIE BEDROCK GRAVEL LANDSLIDE BASED ON MICROTREMOR SURVEY METHODS

The buried depth and geometry of potential sliding surface is the fundamental basis of estimating the evolution mechanism and performing administration of a landslide. The precision of engineering geological survey was closely related to the quality of landslide controlling engineering. Conventional techniques to obtain information about landslide structure were mainly drilling, pitting, trenching and so on, but they were time consuming, more labor and expense, especially a degree of damage on landslide body. These techniques were not conductive to do large scale surveying due to above limitations. In this study, we observed digital signals on the underlie bedrock gravel landslide using microtremor array, and extracted the shear wave velocity structure with Spatial Autocorrelation(SPAC)method. Compared to the boreholes, the results indicated that the depth of stratigraphic distribution and clear underlie bedrock interface basically coincided with drilling with high resolution and without limitation of terrains. MSM was superior to borehole in terms of surveying depth, scale and expense, and allowed a large scale and high density investigation of structure characteristics of underlie bedrock gravel landslide.