| A series of environmental, safety and geotechnical problems are caused by the foundation pit excavation, so it is very important that research on the deformation of containment structure and environmental problems. In Chengdu the deep foundation pit area is generally in the gravel and sand, geological structure is relatively good, but if it is not properly controlled due to the impact of excavation will cause a lot of damage. Taking Chengdu West(Medicine) Trade Center project as the background, taking advantage of the grey theory, statistics and numerical simulation focuses on analysis the design, construction, monitoring and calculating. The main research content of this paper are as follows:(1) The paper reorganizes the related survey data and design data, analysis of the calculation method of supporting scheme. On the basis of No. 5 drilling, analysis three kinds of calculation methods in the supporting structure, to provide reference for the slope and pile anchor supporting structure calculation.(2) This article has carried on the detailed analysis of monitoring data, monitoring project selection should consider those factors. Arrangement of monitoring datas, analysis of deformation law of each monitoring point and the mutual influence of adjacent monitoring points.(3) Investigation report to provide reconnaissance units as the basis, used for numerical simulation FLAC3 D on the foundation. The excavation of bottom soil have influence to nailing axial force, understanding the function of soil nailing in slope-pile anchor structure and using the simulation results further demonstrate it. By using the finite deformation software can be a detailed understanding of the pit excavation condition, analysis the soil deformation, finding the changing rules and contrasting with measured in the same condition to prove the practicability of the model. This project used the prestressed anchor, because of having no monitoring the internal force, it can further understand the bolt’s work status by numerical simulation. Pile as a retaining structure is one of the most important components, the magnitude and direction of the pile have directly related to the safety of the system, this paper focuses on analysis the deformation of pile and uses the measured values to test the accuracy of the model.(4) The introduction of time-varying parameters in GM(1 n) model considers different time and correct the correction value, and it found the predicted value and measured value is very close that prove its practicability in project. Finally, by using Verhulst model and the improved grey model comparison, the model established in this paper has further tested the practical value. |
