Study On Experiment And Numerical Simulation Of Subway Station Roof Beams With Opening

As a hub of urban transportation and a link between ground and underground transportation,the safety and stability of subway stations are important.This paper is based on the research on the key components of a prefabricated subway station in Guangzhou--roof beam of subway station.The stress performance of roof beam after the hole is related to the safety of the station.The main research contents and results of this paper are as follows:(a)To actual engineering as the background,through the finite element software Abaqus,three-dimensional whole station model is established,the extract of open hole in roof beam internal force,and on this basis,the design scale ratio of 1:2.5 test solutions and loading,the mechanical properties of open hole in roof beam in subway station test,including the static loading test and low reversed cyclic loading.(b)The results of static loading test show that under normal working conditions,the crack width of the hole-opening beam is small,and the reinforcement stress is at a low level,which meets the design requirements and has sufficient safety reserve.Before the specimen reaches the failure stage,the component has large deformation and obvious failure warning.The shearing strength of the compression chord at the hole opening position is high,which is a reasonable failure form,and the component shows good ductile failure behavior.(c)In low reversed cyclic loading experiment of plain girder beam,the results show that both showed the characteristics of ductility,girder web open hole on seismic performance of beam itself really weakened,but the hole area of strengthening the reinforcement to effectively restrain the cracks around the produce and development of its bearing capacity is higher than plain girder,the integrity of the beam is not too much weakened,the early stage of the open hole beam energy dissipation even slightly higher than the plain girder.(d)The typical key working conditions are selected in the three-dimensional numerical model.Numerical simulation results show that the effect of simply improving the strength grade of concrete on the bearing capacity of components is not obvious,but it has a negative impact on the ductility.The inclined bars makes concrete and stirrups play a synergetic role in shear resistance,and the crack development and deformation are effectively controlled.With the increase of the hole height,the more the compression chord is prone to brittle fracture and failure of concrete.