Micro-structural Creep Test of Consolidation Process in Tunnel Construction

Abstract

This paper focuses on the microstructure creep during the consolidation process of tunnel construction through the test method. Taking natural soil or remolded soil in coastal tunnel construction as the research object, this paper studies the regional characteristics and engineering properties of soft soil from the perspective of statistics. In this paper, the variation and fractal characteristics of microstructure factors such as particle shape, distribution, arrangement and connection mode in the process of seepage consolidation of soft soil are studied by means of mineral composition test, mercury intrusion test and mercury intrusion test. The results show that: in the process of consolidation, the microstructure type of soft soil changes gradually, from honeycomb structure and sponge structure to skeleton structure, turbulent structure and dense structure. Due to the lack of structure, remolded soil particles are mainly composed of polymers, which are relatively dense. With the increase of load, the particle unit is mainly connected by surface. The quantitative parameters of microstructure of structural units and pores have different rules in different stages of consolidation. In the early stage of consolidation, when the effective stress is small, because the silt soil has a certain structural strength, the microstructure is in the stage of stable adjustment, the number of pores is small, the pore ratio is large, mainly large and medium pores, and the change range of the size, shape and orientation of the structural unit body and pores is small. The research results have a certain reference value for the microstructure creep during the consolidation process of tunnel construction.