The Influence Research On Deformation Of Deep Foundation Pit In Soft Soil Area On Adjacent Building

With the rapid development of our country's economy and accelerating urbanization process,the various usages of underground space and facilities have got an unprecedented development,which generated a large number of deep foundation pit engineering.These deep foundation pit engineering often lies in a more complex urban environment,therefore it not only needs to control the deformation of deep foundation pit itself,but also need to reduce the effects on the adjacent buildings,especially for the deep foundation pit engineering in soft soil area.Therefore,the research on influence of deformation of deep foundation pit in soft soil area on adjacent buildings has important practical significance.The article takes the deep foundation pit engineering of 9th building on Jin Wan square in Tianjin as the research object,on the basis of summarizing research results at home and abroad,combining the methods of field monitoring and numerical simulation,the systematic research was conducted on the deformation of deep foundation in soft soil as well as the influence of excavation on the adjacent national cultural relics.The main research work and achievements are as follows:?1?It introduces the development and characteristic of the foundation pit engineering as well as the research status of foundation pit deformation at home and abroad,introduces the deformation mechanism and the theory of calculation,summarizes the deformation character and deformation law of foundation pit.?2?The author has carried on the comprehensive monitoring for the 9th building foundation pit engineering in Jin Wan square with combining the engineering geological conditions,surrounding environment and the foundation pit supporting scheme.Based on the field monitoring data,conducts systematic research on building envelope,the surrounding earth's surface and the deformation of adjacent building,which acquired the deformation rule and characteristics of building envelope and the surrounding earth's surface,the effects of deep foundation pit construction on neighboring buildings.?3?Based on finite element theory,took the 9^th deep foundation pit engineering of Jin Wan square as the research object,considering the interaction of building envelope,surrounding soils and the adjacent building,the author established 3-D elastic-plastic finite element model,conducted the whole process simulation of deep foundation pit excavation.The article studied the deformation properties of deep foundation pit based on the simulated data,and conducted contrastive analysis on the numerical simulation results and field monitoring data,which verified the rationality and applicability of the model.?4?The article carried out study on the enclosure wall,supporting design parameters and construction method of deep foundation pit deformation with adopting the method of single factor sensitivity analysis based on numerical simulation,from which found the influence law of the various factors on the deformation of deep foundation pit,and then found the measures and the methods for controlling deep foundation pit deformation and reducing the differential settlement of the adjacent buildings.Through the research work of this article,some meaningful conclusions are obtained,which can provide certain reference for similar deep foundation pit supporting design,construction method and the protection of adjacent buildings.