Numerical Analysis And Optimization Of Deep Foundation Pit Retaining Structure

For nearly 30 years,with the rapid development of national economy and the increasing of population,the ground transportation in the city can't meet the Daily needs of the People,the development and utilization of metro engineering appear.The subway station is located in the urban traffic and relatively dense population areas,the station and its surrounding existing buildings has more contact,the construction difficulties are greatly stimulated the rapid development of the deep foundation pit engineering design and construction level.In this paper,combined with Shenyang metro line 9 and 10 line interchange station deep foundation pit engineering,there is more adjacent buildings near this project,engineering environment is relatively complex,the construction of deep foundation pit is quite challenging.This paper adopts the Li zheng software to analysis the excavation process,mainly through the following several aspects to change the parameters of the retaining structure of foundation pit,to study on the displacement deformation.1.Retaining pile diameter of 1m,on the base of pile spacing of 1.4 m,according to magnify by every 0.1m,and retaining pile spacing of 1.4m remains the same,according to reduce the size of diameter by every 0.5 m.Through simulation analysis can be found that increasing the retaining pile spacing and reduce the retaining pile diameter will cause the displacement of the retaining pile increase,and the displacement is growing rapidly.2.In the numerical simulation of the first and fourth position have been adjusted.Simulation results show that the first steel support level is lower,the greater the horizontal displacement on the top of the pile is.the forth steel support elevation is higher,the most horizontal displacement of the pile body is smaller,so when we design,we should increase the forth steel support elevation far as possible within the scope of the support allowed.3.In the process of simulation we select five different horizontal spacing steel support to numerical simulation analysis,with the increasing of the support horizontal distance,the horizontal displacement of retaining pile body increases gradually,thus reducing the level of support spacing is a good way to reduce the deformation of foundation pit.4.Adjusting the additive axial forces of steel support,adopts the steel support prestressed respectively 0%-85%of design axial forces to analyze its impact on retaining structure.By the results we can be found that adopt prestressed in the process of increased from 0 to 85%,the pile horizontal displacement is gradually smaller.We can see that using increasing steel support axial force of prestressed,we can effectively reduce the deformation of foundation pit retaining structure.Finally the simulation results compared with foundation pit engineering field monitoring data,and in combination with the above several kinds of adjusting method,we propose the optimized design scheme.By analyzing before and after the two kinds of schemes,it can be seen that the optimized scheme not only satisfies the requirement of construction safety,but also improve the stability of retaining structure,reduces the project cost,convenient construction process.The optimized scheme is not only the desired scheme,and highlights the importance of numerical simulation analysis in engineering construction.At the same time monitoring results can also be for other similar retaining structure of foundation pit design and construction experience.