Slope stability analysis at Bloemendhal Open Dump Site in Sri Lanka

Abstract

Civil engineering construction in the Colombo city area have commenced on lands previously used for the dumping of waste. Construction on covered dump wastes will cause a lot of problems, such as settlement, slope instability, and shear failure. Therefore similar to soil properties, it is important to study the properties of sol id wastes to predict settlement, slope stabil ity and shear strength parameters, though there are additional differences due to some chemical reactions occurring in the solid waste with time. In this research, the geotechnical properties of solid waste from a dump site called Bloemendhal was studied. Several tests we re made to ide ntify and classify the so-called soils taken from the this location. Basic tests such as sieve analysis, Proctor compaction, consolidation and direct shear were conducted. Open dumps are some times higher than I 0 m. There is a huge risk of slope fa ilures due to any modification of slope geometry or loading above. Therefore, in this research, that aspect was considered as an important issue. Several sections where possible failures could happen were analyzed using Geo-Slope software, using the results obtained from basic tests. Factor of safety va lues obtained for the existing conditions and with possible loading imposed due to any future constructions are discussed.