IN-SITU TESTS AND SLOPE STABILITY ANALYSIS OF MUNICIPAL SOLID WASTE LANDFILL

摘要

Due to the limitation of population density and availability of land, a large portion of the landfills of Taiwan, China are located in mountainous area. Current regulations do not require slope stability analysis for these landfills. As a result, almost all of the landfills were not designed to maintain a suitable factor of safety against failure. The composition of Taiwan's solid waste differs considerably from that of the United States or any other country in the world. However, the lack of data of local solid waste poses a great limitation to engineers. The objectives of this research are to collect shear strength data from in-situ tests and perform a series of stability analyses. The results show that the cohesion and friction angle of the MSW at Chu-nan and Hu-kou landfills are 34.9 kPa and 37.9°, 33.6 kPa and 32.1°, respectively. In addition, the coefficients of subgrade reaction, kv, are 875.25 kN/m3 and 494.33 kN/m3, respectively. Results of 2-D and 3-D slope stability analyses show that the factor of safety increases with lower height of wastes, longer length of waste body, smaller slope angle of the back of the excavation, and steeper face slope of final cover. In addition, 3-D analysis indicates that the factor of safety decreases with the widening of the mouth of the landfills on slopes.