Assessment of erosion resistance of biocemented sandy slope subjected to wave actions

The microbial induced carbonate precipitation (MICP) technique has been increasingly employed for ground improvement and fracture sealing, as well as for erosion mitigation and stabilization of sandy slopes. However, there is a lack of an effective assessment method to estimate the erosion resistance of biocemented sandy slope under wave actions. In this study, a series of bench-scale flume erosion tests was conducted on sandy slopes with and without MICP treatment under waves to quantitatively investigate the erosion resistance. Variables, including the MICP treatment cycle(0 similar to 4 cycles) and the slope angle (10 degrees, 20 degrees, and 35 degrees), were explicitly con sidered. Penetration tests were conducted to measure the strength of biocemented sand at the slope surface. The calcite mass was calculated using theacid washing method to evaluate the level of cementation. Results show that the erosion resistance follows a nonlinear relationship with the penetration resistance. A fitting calculation was therefore carried out to evaluate the erosion process of MICP-treated sandy slope based on the results oferosion and penetration tests for use to assess the slope stability. A microstructure study also shows that there was interlocking cementation produced between sand particles in the sandy slope after MICP treatment,whichcontributed to the increase in erosion resistance ofsand.