Optimum Design And Contrast Analysis Of Bracing Scheme For Deep Foundation

In recent years,with the appearance of large-scale construction of deep foundation pit,the complexity and technical difficulty of the foundation pit is is increasing as well.Higher requirements are put forward bythe design and construction of deep foundation pit engineering: to make the foundation pit safe,stable and reasonable,but also save the economy and and control the influenceof the surrounding environment.Therefore,through the optimization of the supporting structure,the study analyzes the force and deformation of retaining structure in the process of foundation pit excavation,and it is very important to guide the smooth implementation of the foundation pit engineering.On the basis of theory and the practice of deep foundation pit engineering and the specific engineering geological conditions,hydrological conditions surrounding environmentand hydrological conditions of a deep foundation pit project in Beijing,the design and selection of foundation pit scheme is carried out on the basis of predecessor's research and monitoring studies,the main conclusions are as follows:(1)The reasonable selection of foundation pits supporting structure types,according to the relevant theory and Practice for selecting the pile anchor supporting structure and double row pile-anchor cable two pit type,and the primary design of two kinds of foundation pit supporting scheme using Lizheng software design,according to the final results,the double row pile-anchor cable is the ultimate foundation pit supporting scheme.(2)Detailed design of primary row pile-anchor supporting schemes,and monitoring of the monitoring methods adopted are: supporting pile top horizontal and vertical displacement of the pile body,deep horizontal displacement,surface subsidence,groundwater level monitoring,the internal force of prestressed anchor cable etc..And the measured data were analyzed,the results show that the displacement of retaining structure varies from the condition of foundation pit excavation,and the deformation of foundation pit soil can be controlled well by double row pile-anchor retaining structure.(3)Comparative analysis of test results and the foundation of Lizheng software calculation results show that the design of deep foundation pit deformation is far greater than the actual deformation,design of deep foundation pit design software for a large safety reserve,verifies the rationality of scheme design.(4)The problem of foundation pit engineering is comprehensive and complicated,and there are differences between theoretical calculation and experimental results there are some differences.The better development of foundation pit engineering cannot be separated from the theoretical calculation results.Meanwhile,the actual monitoring data can verify the rationality of the design scheme,and it also can be used as a complement of the results of theoretical design.The research results of this paper can provide some references and reference for the optimization design and construction of similar building foundation pit engineering.