Abstract:
To investigate the soil compression and consolidation properties and analyze the influencing factors of soil deformation from a macro perspective is an important aspect for exploring the causes of land subsidence. Taking soil samples from the hydrogeology and engineering geological comprehensive test hole HZ22J06 in the key area of land subsidence in Hangzhou as an example, and the physical properties, compression deformation and consolidation characteristics of the soil were analyzed and studied by indoor testing. The results reveal a significant correlation among the physical indexes of the soil in the test holes, and the parameters of water content, specific gravity of soil grains, void ratio, plasticity index, liquidity index and compression coefficient show an overall trend of first increasing and then decreasing with the increase of depth. The compression coefficient of the soil samples generally decreases with increasing pressure, with shallow samples having higher compression coefficients compared to deeper ones. Furthermore, there is a close correlation between the consolidation coefficient and hydraulic conductivity of soil. Under the same pressure, the variation of the consolidation coefficient of different types of soil samples follows the law of silt>silty clay>muddy silty clay>soft clay, which is consistent with the variation law of hydraulic conductivity. Additionally, most of the soil samples in the test holes are in an under-consolidated state, which may cause further consolidation and compaction, leading to land subsidence. The research results could provide scientific basis for the study of the causes of land subsidence and risk prevention and control in Hangzhou city.