关键词: 相似土;配和比;微观特征;敏感性分析;富水砂层;

Abstract: Similar geological model test is an important method for geotechnical engineering research such as deep foundation pits.However, there are still many deficiencies in the research on the selection of similar materials, preparation technology and test applicability.In this paper, taking a foundation pit project of the East Bus Station of Nantong Metro Line 1 as the research object, on the basis of understanding the geological conditions of the water-rich sand layer in the area, according to the development requirements of soil similar materials, fine sand, barite powder, laundry detergent, bentonite and water were selected as the raw materials.Based on the orthogonal test method, the physical and mechanical parameters of similar soil under different mixture ratio conditions were measured, and the sensitivity factors were analyzed.In addition, the influence mechanism of various factors on the properties of similar soil and its micro-structure characterization were further analyzed.The results showed that the density of similar soil was controlled by the barite content and the two were in positive correlation.Cohesion was controlled by water content and bone washing ratio, which showed a negatively correlation.The internal friction angle was negatively correlated with all factors and was controlled by barite content.The compression modulus was negatively correlated with the three factors except water content.The physical and mechanical parameters of similar soils with different mix ratios were widely distributed in the test, which can provide a reference for similar model tests.

Key words: similar soil; mixture ratio; micro-structure characterization; sensitivity factors analysis; water-rich sand layer;