Research On Field Monitering Of Deformation Rule About Support Structure And It's Optimization In Chengguan High-Speed Railway Deep Foundation Fit Engtineering

With the rapid development of rail transportation, the subway project in the city has entered a booming period.In the process of the subway construction, more and more problem has been presenting,such as the engineering security problem for the excessive pursuit of the economic,vice verca the economic wasting problem for the excessive pusuit of security. Therefore,the design of Retaining Structure(RS) has been one of the key issuse in the subway construction.As a result,the research of deformation nature monitor and optimization to the RS for deep has a very important engineering utility value. The paper is based on the monitoring project of Lidui part tuunel foundation ditch for Chengguan high-speed railway.The main contents and conclusions are as follows:1, The deformation mechanism to the RS for deep is analyzed from three aspects:the bulge of soil in the bottom of a pit,fenderpost displacement and site settlement behinde of a wall.Then the main factors effecting the general pattern of excavation damage and excavation deformation are summed up.2, I gives the monitoring program of the high-speed rail tunnel excavation exterior-protected structure construction and complete the on-site monitoring.With the calculation and analysis of the on-site monitoring data,the general nature of the cobblestone ground piling and steel shotcrete supporting structure deformation is summarized emphasized on the pile body horizontal shift,crown cantilever shift,steel shotcrete shaft force and pile body internal force.3, I analyze the data simulation in the process of deep excavation using the Geotechnical Engineer finite element software PLAXIS. Then I compare simulation result with the factual monitoring data and find that they are basically consistent.For these,I verify the rationality and effectiveness of the finite element model.4, I make a optimal design to the deep excavation supporting structure parameter using the orthogonal test method which is based on the finite element numerical simulation.The result indicate that it will be find that:the main effect significance of main supporting structure parameter to pile body shift in turn will be pile diameter,pile space,steel shotcreteif space,pile length;for the construction cost the effect significance in turn will be pile diameter,pile space,pile length,shotcreteif space;further more,the optimal parameter is 0.8m to the pile diameter,2.8m to the pile space,15m to the pile length,7m to the shotcreteif space.All of the results are based on the evaluating indicatorthe pile body shift and supporting structure construction cost.