Studies On Pile-soil Interactions And Soil Arching Effect In Composite Supporting Structure Of Foundation Ditch

With the accelerated urbanization process and the improvment of people life quality, the government has increased the input of infrastructure construction, many cities have started metro projects. Simultaneously, due to the scarcity of urban land, more and more high-rise buildings, underground space's development and utilization become an important way to try and ease congestion in the city. Therefore, in recent years a large number of deep excavation project, and many new forms of the supporting structures have emerged.Deep foundation pit support mostly be temporary, which is to ensure that the main project such as housing construction, subway construction, underground engineering, and other infrastructure in the smooth implementation, but it's also a directly impact on the economic benefits of the project, project progress and construction safety. So study on the supporting form, which saving expenses, controlling costs, guaranteeing security, not causing construction delay become especially valuable.Pile-anchor-braced composite supporting structures fully use the advantages of various forms of support, widely used in many deep excavation engineering. In this thesis, a deep foundation pit in Hainan is adopted as an example, according to the monitoring data, we have discussed on the reasonable pile spacing in this condition of pile-anchorage-support composite support system. Moreover, we have studied on certain questions of the arching effect in soil of pile separation by extended models.This thesis gave a detailed description of the site and monitoring conditions, and analyzed the horizontal displacement of pile at different site conditions. Associated with actual measurement data, we simulated the excavation process by using the software FLAC3D, comparative analysis the calculated results with monitoring Data, theoretical formula analytical solution and calculated results with deep foundation ditch design software F-SPW, which confirmed the rightness of the numerical model and reliability of the program. Finally, we adjust the pile spacing, conducted multiple simulation, and analysis of their results obtained in this condition, and arrived at the rational pile spacing. And further on, we have studied on some other frontier issues, such as, the relationship between soil arching effect and soil pressure and the thickness of the soil arch between piles.