The Study Of Wall-anchored Support Technology And Its Numerical Simulation

Based on the subway station in Wuhan Rail Transit Line 2, a deep pit structural engineering, this paper takes the wall-anchor enclosure structure for the study object. It mostly studies on the contents of the stability of interaction between soil and enclosure structure by means of theoretical analysis and numerical simulation. Through the traditional method of equivalent beam, it calculates and analyzes the design of the enclosure structure, besides, by the finite difference software FLAC, the numerical model is established, which mainly studies the deformation characteristics of the enclosure structure and soil, the force of the anchor as well as other relevant content. The main contents and conclusions are listed as follows:1. The paper introduces the characteristics of the diaphragm wall and prestressed cable, summarizes the application conditions of wall-anchor enclosure structure, and discusses its interaction mechanism. Finally, it is proved that the wall-anchor enclosure structure is a very good measure to control the displacement and it meets the requirements of hanging-rail row.2. Due to the depth of pit, 18 meters, and the existence of weak formations, it sets up seven rows prestressed cable. Through the analysis and discussions the final analysis method in the paper is decided, by equivalent beam method (traditional method), the paper analyzes the enclosure structure, obtains the depth of the diaphragm wall and the internal force of the enclosure structure. Moreover, it also designs the length and the configuration of the cable. Finally, the analysis arrives at a conclusion that the average length of the anchor is 30 meters; the sixth row of anchor has the largest axial force, 521.65 kN.3. Various construction conditions of the pit has been simulated dynamically by FLAC procedures, with the analysis of the force in different periods and the deformation characteristics of the enclosure structure and soil, which arrives at the conclusion that the main displacement of the structure appears 32 H upwards (H is the height of the wall), the largest displacement, 26.42mm, appears on the top of the wall. Based on these conclusions, the paper has made some monitoring points in these positions in order to monitor the deformation of the pit and to offer reasonable suggestions for the construction of the wall-anchor Enclosure Structure.4. At last, the paper analyzes the causes resulted in the differences between theoretical method and numerical method, so as to provide reference recommendations for the application of the wall-anchored enclosure sructure.