The Force Analysis And Optimum Design Of Large Open-hole Structure Of Subway Station

With the continuous development of China’s urbanization process,The major large and medium-sized urban transport systems are facing enormous challenges.Now,most of them are vigorously building subway to ease the increasing traffic pressure.During the construction of the subway,Due to construction needs,The floor of the station will be reserved for different sizes of openings,such as rails,shield wells,equipment hole and so on.Under the influence of earth pressure,There are obvious difference in design calculation between the large size of holes portion and general structure in subway station.However,most of the researches on the structure of underground stations are concentrated on the internal forces of conventional structures,There is also a lack of depth and meticulous research on the reserved subway station.so It is necessary to have a comprehensive analysis of the internal force performance of the large-sized underground station.This paper takes the data of a physical station in Zhengzhou as the engineering background.Establishing three-dimensional stratigraphic-structure model by the finite element software MIDAS / GTS NX,The model includes a support structure,a large open-hole station structure and the surrounding soil.Through the simulation of the construction steps of the station.Firstly,under the pile support system,the model has analyzed the influence of the pile depth,pile stiffness change,pile arrangement pitch,additional load,pilaster to the force and deformation.Secondly,on underground continuous wall,the influence of the wall stiffness,the stiffness ratio of the wall to the wall and beam-to-wall,the density of column spacing also have been analyzed.Finally,compares the internal forces of different structures before and after opening,finds out the unfavorable position,then puts forward some optimization plans,such as side wall outside with ribs beam,single column reinforcement,increase the ring beam.