Construction Technique And Stability Analysis Of Deep Foundation Pit For The Kunming Yinxing Jinchuan Huayuan Project

Along with the development of the high-rise buildings and underground projects, the requirement for deep foundation pit become higher and higher, and also a topic with more and more attractions. The supporting type choosing, mechanics analysis of support structure and study on stability of deep foundation pit are important problems in the geotechnique field. Based on the deep foundation pit project of Kunming Taiyi bridge Yinxingchuan garden, modified recommendations for the future objects'deep foundation pit technological have been raised in this paper, using a software FLAC3D toestablish model of the construction phase simulation method to analysis the process and observe the settlement and displacement. The main content of the study are as follows:1. The development of deep excavation works,common problems of supporting and future developing trends have been discussed in this paper.The author has summarized the design theories of deep foundation pits. At present, the most common mothods for analysis are limit equilibrium method and elastic resistance method.With the development of computers, finite element analysis mothod has also been more and mor ewidely used.2. This paper based on the deep foundation pit project of Kunming Taiyi bridge Yinxingchuan garden, simulated the actual excavation and the step-by-step support of the construction process,analysed the horizontal displacement of support structureand the ground surface sedimentation.Simulation results show that the greatestvertical pit settlement is 10mm,the maximum of the support structure horizontal distortion is 20 mm. Monitoring results show that the compound supporting papers design pattern is safe, the feasibility of the design has been verified.3. This project adopts a new construction technology-spiral sprayed soil anchor, introduces its construction technology, machinery and working principles. In the end, FLAC3D are used to build a partial thre-dimensional numerical model, simulated the evolution of displacement during the excavation, and compared the monitoring results, which obtained a comprehensive reference significance for the deep foundation pit.The monitioring data show that themaximum monitoring vertical surface subsidence is 24mm,the maximum horizontaldisplacement is19mm.There are some differences between the monitoring data and simulation data, that is because the actual project was affected by the construction disturbance and also the environment, groundwater, construction season, climate, load distribution and other factors, while the simulation model had varying degrees of simplification, the selection of parameters in simulation also had an effect on the results.