Geotechnical properties of synthetic municipal solid waste

Abstract

This paper presents the results of laboratory investigation performed to determine the geotechnical properties of synthetic municipal solid waste (SMSW) simulating typical composition of municipal solid waste (MSW) generated in the United States. Initial characterization of SMSW was performed through the determination of particle size distribution, moisture content, and organic content. Hydraulic conductivity, compression ratio, and shear strength were studied for their variation and significance through replicate testing. Hydraulic conductivity ranged between 1.2 × 10^-5 to 7.62 × 10^-8 cm/s which is lower than that of field MSW, mainly due to the use of low-permeable glacial till soil to represent inert fraction of SMSW. Compression ratio ranged between 0.16 and 0.31 which is within the range reported for fresh MSW. Drained direct shear tests resulted in cohesion 16-19 kPa and friction angle 27-29°; these results are within the range reported in the literature for fresh MSW. Based on the results from triaxial consolidated undrained (CU) shear tests, SMSW exhibited cohesive behavior with 22 kPa cohesion and 7° friction angle as the total stress parameters. This study showed that the compressibility and direct shear behavior of SMSW tested during this research were similar to fresh MSW, but hydraulic conductivity and triaxial CU shear strength were different. Replicate testing and statistical analyses demonstrated that the test results did not vary significantly hence repeatability was assured.