Optimum Design Of Subway Station's Inverted Beam

The traditional metro station structure design is too conservative,there are many problems such as unreasonable design and waste of resources.One of them is the design of the beam on the top of the metro station.The shearing capacity of the upturned beam structure is weaker than that of the general beam,and the upwardly convex structural form brings great trouble to the construction of the structure itself and the back filling of the pit in the later stage.For example,the elevation of the pipeline is adjusted,the quality of the station backfill is not ideal,and even the uneven settlement of the roadbed is caused.In order to reduce the adverse effects caused by the structure of the upturned beam and improve the construction conditions of the roof and backfill of the station,this paper takes the station of Fuzhou Metro Line 2 as an example to study the structural design optimization of the metro station.Through the detailed analysis of the action effect and the finite element analysis of the mechanical behavior of the longitudinal beam of the station roof,the main problems in the current design are found out,and the structural resistance requirements are met,the construction is convenient,the economy is more reasonable,and the height of the beam on the roof is lowered.Next,the structural optimization method and construction.details of the upturned beam are proposed.The main contents and conclusions of this paper are as follows:1)The detailed analysis of the structure and its combination shows that the current metro station structure design overestimates the effect S,and the structural resistance R of some components is excessively redundant;detailed analysis should be carried out for specific working conditions,and Accurate calculation of the benefits.2)The analysis of finite element calculation results shows that the bending moment in the plate calculated by the plane model is too conservative,especially at the position of the column end and the wall end;the plane model overestimates the shear capacity at the structural longitudinal beam in the analysis;When designing,the calculation results of the planar model should be corrected based on the results of the overall internal force analysis and local stress analysis of the space model.3)The two optimization schemes based on the reinforcement method and the H-shaped steel reinforcement method meet the structural design requirements and are reasonable and feasible.Compared with the original design scheme,the economics of the reinforcement method is basically the same as the original scheme,but the performance of the reinforcement is improved.The optimization scheme of the H-beam reinforcement method is more technically reasonable,but the cost is slightly increased.