Experimental Study on Pore Pressure Variation and Erosion Stability of Sandy Slope Model under MICP

Abstract

With the development of free trade port in Hainan Island, the construction of tourist roads around the island is also in full swing. Under the weather conditions of strong typhoon and rainstorm in Hainan, the highway cutting slope built on the coastal weak sandy terraces has strong sand loss and is easy to be scour by rainfall. MICP green spray irrigation solidification technology is used to strengthen the sandy cutting, and pore water pressure monitoring is carried out on the slope model during MICP solidification and rainfall scour. Combined with the model pore water pressure and flow slip failure pattern, dynamic analysis was carried out. The results show that MICP sprinkler irrigation technology can solidified the surface of the slope model in a short time, and the cementation depth of the model reaches 4cm after three sets of rotation reinforcement. The surface reinforcement effect is good, and the sand samples are closely connected. Under the erosion effect of simulated rainfall intensity, the sand loss of the slope is weakened, and no sand binding damage occurs, and the integrity is enhanced. Due to the cementation between sand grains, most of the rainfall was converted into runoff, and the slope slid after 150s. When the slope began to slip, the leading edge of the slope model lost sand and unloaded, and the failure mode was graded creep slip failure. Finally, the slope was divided into several blocks due to the continuous expansion of cracks after the slope failure. The erosion stability of the sandy slope under heavy rains is optimized and the sand loss is prevented effectively. In this study, a new method of MICP remediation techniques is proposed, which provides a new test basis for the application of MICP technology in practical engineering.