Study on active control scheme of settlement of adjacent important buildings caused by super deep excavation in soft soil area

Abstract

In order to solve the deep foundation excavation causes nearby existing station produces large deformation problems, using finite element software, grouting is carried out in the stratum between the deep foundation excavation and the existing station, push the subway station structure to the inside of the foundation excavation, thus the horizontal displacement of the station is controlled within a smaller target value. Different grouting positions are studied and three grouting method are proposed, which are through-length grouting, segmenting grouting and multi-point grouting. Through-length grouting means that the grouting amount per unit length remains the same from top to bottom in the whole grouting range.Segmenting grouting refers to dividing the range of grouting into several sections of equal length grouting body, and the grouting amount per unit length of each section is determined according to the stratum displacement of the position of the grouting body. Multi-point grouting refers to the fact that the length of several independent grouting bodies is very small, and only concentrated grouting is carried out at the depth of the station floor. The amount of grouting of each grouting body is determined according to the displacement of the stratum. By comparing the stress of station structure under different grouting conditions when the same station deformation control target is achieved, the best grouting scheme is selected.

Keywords

finite element simulation / ultra-deep foundation excavation / adjacent station / grouting