Combined approach for site investigation in terms of the analysis of rainfall induced landslides

摘要

The risk of surficial landslide events arising increases wherever the combination of intense periods of rainfall, steep topography and soil conditions are critical. Monitoring of the condition of the ground can provide valuable information for the risk assessment of potential landslides. Prior to installing the instruments, a detailed site investigation is essential. Ideally, both monitoring and initial site investigation should deliver high-resolution 3D spatial information about the soil conditions without creating disturbance such as artificial paths of infiltration. An integrated investigation of a test site is presented. Results of geological, geophysical and geotechnical methods are compared and used to derive an integrated model. In addition to geological studies and classical geotechnical testing including dynamic penetration tests and analysis of soil samples, a geophysical investigation was carried out using electrical resistivity tomography. The integrated model of the subsurface resulting from several complementary datasets suggests that this procedure is very useful for optimising the design of a monitoring system, in terms of quality, cost efficiency and predictive capability of the hydro-mechanical models derived from, or validated by, the planned monitoring system for areas likely to be subject to landslides.