GTS Simulation For Deep Foundation Pit Excavation Of Pile- Anchor Retaining Structure

Since the construction of urbanization in China, deep foundation pit engineering has been developed rapidly, the number and difficulty of the construction has been increased, because of the deep excavation, the long excavation cycle, and the surrounding environment and geological conditions, the stability of the deep foundation pit construction process has become the focus of our attention. Among the many methods of deep excavation, pile- anchor retaining structure for its space-saving, convenient construction, supporting effect and many other advantages have been people of all ages.In this paper, with the background of a practical project in the Handan City, pile anchor supporting structure of deep foundation pit excavation construction process was simulated by finite element software MIDAS / GTS, under various conditions are studied deep foundation pit lateral displacement, vertical displacement, surrounding ground settlement deformation law, and makes a comparison with Lizheng software design results and the actual monitoring data. The main contents are as follows:(1) The research background, characteristics and common support types of deep foundation pit engineering are briefly introduced, and the research results of the domestic and international research on the anchor supporting structure are summarized.(2) The deformation characteristics of deep foundation pit, the supporting principle of deep foundation pit, and the mechanism, characteristics and failure mode of the pile anchor supporting structure are introduced. And access to relevant data, the authors summarize pile anchor supporting system of common design calculation method, using Lizheng software of engineering examples of earth pressure, calculation of the displacement of pile, foundation pit stability, anti uplift checking, and makes the corresponding analysis and summary.(3) Introduce the finite element theory and the realization process, and introduce the application of Midas/GTS in the field of geotechnical engineering and the concrete modeling process. Using the GTS establish a foundation pit engineering model, analyze and summarize the regularity, and the force, displacement, foundation pit heave, the surrounding ground settlement in soft soil deep foundation pit excavation. Comparison of Lizheng software calculation results, GTS numerical simulation result is more close to the actual monitoring results, numerical simulation analysis result conforms to the actual situation and can be adopted.(4) Analysis of retaining pile diameter and pile spacing influence the displacement value and the relationship between the level of foundation pit. Appropriate increase supported supporting pile diameter or decreasing pile spacing can reduce the horizontal displacement of deep foundation pit, but pile diameter increases to a certain value or pile spacing decreases to a certain value, lateral displacement of foundation pit reduction effect not ideal. Taking into account the economic nature, this project selects 0.8 meters diameter is more reasonable, can be in the weak area set 1 meters of pile diameter pile, pile spacing can choose 1.6 meters.