Effect of initial compaction state on erosion potential for cover liner

Abstract

Multi-layered cover system (MLCS) is constructed upon hazardous landfills that has reached its full potential. Soil erosion is a primary stressor of surface soils used in MLCS, which ultimately results in exposure of lower layers. The effect of compaction state is crucial to assess erosion potential of compacted surface soil used MLCS. The erosion potential needs to be studied as a function of initial compaction state, soil type and flow rate, under high intensity rainfall conditions. For this purpose, a well-established pin hole test was used to evaluate the erosion potential of soil. A total of 324 pin-hole tests on four loamy soils were conducted and the individual effect of initial moisture content, soil density and flow rate was discussed. It is observed that compaction process in top surface of MLCS can be done at wet of optimum moisture content (OMC) with highest maximum dry density (MDD) to minimize risk of erosion related failure. The compaction state of (OMC+5, 1.05MDD) is suitable for top surface design as it showcases significantly lower erosion rates than the permissible erosion rate for cover systems.