Research On Bracing System Optimization In The Deep Foundation Pit Of JuZiZhou Subway Station

With the rapid development of domestic subway, a large number of deep foundation pits are used in the subway construction project. How to control the deformation of the deep excavation, for the purpose of foundation construction safety and economy, has became the focus of research. This paper relies on the key construction techniques research of JuZiZhou deep foundation pit, takes the JuZiZhou deep foundation pit as the engineering background. Using the FLAC finite difference software to analyze the law of deep foundation continuous wall in the case of different water level, and the deformation characteristics of continuous wall at high water levels is analyzed, when deep foundation pit was taken reinforcement measures. Based on the characteristics of rock strata under JuZiZhou deep foundation, the deformation of the continuous wall under different insertion depth of the wall, support stiffness and support numbers was analyzed. The supporting system of deep foundation pit was optimized, which includes grouting reinforcement, support structure and envelope structure. This main research work includes:(1)Relying on JuZiZhou deep foundation pit, the structural deformation of the foundation pit under different water levels is simulated. The deformation of envelope structure under high and low water level can help determine the safety of the foundation construction.(2)According with monitoring measurement data of JuZiZhou deep foundation pit, the research acquired by means of numerical simulation has showed the deformation of envelope structure with grouting reinforcement under the action of the high-water. The soil grouting reinforcement parameters outside the deep foundation pit are optimized, which based on the control objectives of envelope structural deformation.(3) According to the effect that surrounding strata made on the envelope structure deformation, based on the characteristics of rock strata under JuZiZhou deep foundation, the envelope structure deformation with grouting reinforcement under different rock-socketed depth is analyzed, support stiffness and support numbers. Besides, deep foundation support parameters are optimized.