Stability of refuse landfill reinforced by stone columns

This paper presents the design, construction and performance of ground treatment to support road embankment on refuse landfill in Korea The long-term settlement characteristics of refuse landfill were analyzed by Sower(1973);Yen and Scanlon(1975). As a result of field test, the predicted settlement exceed the allowable settlement and ultimate bearing capacity is not satisfied. Therefore, refuse landfill was treated by stone columns. The effectiveness of dynamic replacement was verified by Standard Penetration Test(SPT), Plate Bearing Test(PBT), Pressuremeter Test(PMT) performed before, during and after construction of the stone columns. From the loading test, estimation of critical embedded ratio to classify the failure mechanisms, critical and yielding pressure on treated and untreated ground is suggested. Also deformation modulus of stone columns and untreated ground is suggested. The results indicated that the settlement of the treated foundation should be reduced to about 70 percent and the bearing capacity should be increased to about 60 percent comparing with the treatment. Due to the non-homogeneity of refuse landfill, stress concentration factors were distributed in wild range.