An experimental investigation on shear strength and liquefaction response of pond ash for road embankment construction

Abstract

The use of pond ash for the construction of road embankments is a prudent method of its utilization. However, the pond ash at different locations exhibits spatial diversity in the ash pond itself due to its hydraulic deposition in slurry form through pipes in the disposal site. The characteristics of pond ash are not uniform over the entire spread of ash pond. The current study focuses on the shear strength and liquefaction response of several pond ash specimens (S0-S100) with different percentages of coarse content, where S0 indicated the fine pond ash (Particle size: 75 micrometre-5 micrometre) and S100 represents coarse pond ash (Particle size: 4.75-75 micrometre). Direct shear (DS), Consolidated undrained (CU) triaxial, Bender element and Cyclic simple shear (CSS) tests were performed on several pond ash specimens (S0, S20, S40, S60, S70, S80, S90, S100). The DS results indicated a rapid increase in the angle of internal friction from 31 degree to 39 degree for S0 to S100 specimens, respectively. The peak deviatoric stress and dilative response increased with increasing coarse content (0% to 100%; S0 to S100) under CU triaxial conditions. The CSS test results exhibited a large increase in liquefaction resistance with increasing coarse content (0%-100%). In bender element tests, small strain shear modulus response exhibited similar results for all pond specimens with coarse content (0% to 100%).