Deep Foundation Pit Supporting Design And Numerical Simulation Of The Stability Analysis

The excavation engineering incorporates many subjects such as the geotechnique and structure engineering into an organic integrity, which is highly comprehensive and influenced by many factors. In the excavating process, not only the stability of excavation should be ensured in order to construct all kinds of engineering both inside and outside excavation safely, but also the safety of facilities such as adjacent buildings and underground pipe-lines should be ensured. So doing research about the displacement after excavation and the stability of soil and supporting structure is an essential problem.At present, the theory of deep excavation supporting design is not perfect, model tests and engineering tests are still needed to be further developed. Under such condition, in actual engineering, sometimes in order to ensure security, investment has been increased, which creates unnecessary waste; on the other hand, sometimes in order to pursue economy, the control requirements of the stability of the pit and the deformation is decreased, which causes project accident that results in greater economic losses. Not only design but also construction should be stared from the overall system, which is the reasonable way to resolve this contradiction. A good integrity is formed only if various parts of the system are coordinated well. In light of the deficiencies in the study about the deep pit, the deficiencies in traditional design calculation is analyzed through the comprehensive use of the deep excavation software design calculation and numerical simulation analysis. It gives design reference and verifies analysis.The Guiyang movie town and complex building deep excavation project is taken as an example. The application of the combination of the advantages of the famous rock FLAC3D and domestic Lizheng deep excavation supporting design software is searched. Firstly using FLAC procedures is adopted, the non-supporting state is simulated, and the weak parts in excavation process is found, focus on the weak parts, sprayed concrete panels + soil nailing method is used, Lizheng supporting design is taken. Secondly the entire process of excavation step-by-step excavation and supporting is simulated by using FLAC software; the modeling result is used to analyze the change law of the displacement distribution and the stress distribution of the pit slope soil, the internal forces of the supporting structure is analyzed. In the end, the stability of excavation and supporting is appraised by using strength reduction method. Through FLAC simulation analysis, the result that the supporting design meets demands in the process of excavation is attained. It verifies that the Lizheng supporting design is rational and effective, and provides reference for engineering design and construction. The great practical significance of the combination of the two is clarified.