Studies On Hand-Dug Pile And Soil Interactions For The Deep Excavation Of Subway Stations

Since china's reform and opening up to the outside world, our national economy develops rapidly and city transportation becomes increasingly jamed Subways are safe, quick, comfortable and environmentally-friendly, what's more they can contain large quantities of passengers once. Subways are superior to any other vehicles and take up little of the ground which gets more and more valuble and occupied, so every properous city in our country is planing or will plan to develop subways to ease the tranport pressure.As the construciton of subways are booming, the digging and support of the deep excavation of the subway stations arouses people's close concern. The retaining piles of the hand-dug piles are widely used in supporting the pits of the subway stations, for they are cheap, simple, reliable, space-saving,convehient to operatate with little effects on surroundings.Based on the design and construction of the supporting enclosure of the pit of Tong Zilin Station ,one station of Chengdu's First Subway, the detecting statistics of the pits during construction, the thesis is mainly to research the interval of hand-dug piles in deep gravel soil ground. The thesis is to conclude the present status of research and design of hand-dug piles, discuss the potential problems and main evidences of designing hand-dug piles and lay much emphasis on analysing the effect of soil archs of piles' interval.Then simulate the real situation of the Tong Zilin Station with Ansys, a gigantic limited computer software, and verify the models reliablity by comparing and analysing the results from numerical simulation, calculation based on the theory of soil arch and monitoring data of the construction site.Finally, we adjust the pits' interval of the dug piles, re-simulate numbers of several groups and anlyse the results. We draw a conclusion that the changes of pits'interval have some effects on soil archs' stability between piles and pits safety, even if the geological conditions and pile drives are definitely unchanged. The thesis provides certain reference for the future design of the hand-dug piles of the pits with geological conditions similar to what we researched.