Research On Influence Of Tunnel Lining Rigidity On Structural Dynamic Response Under Train Load

Over the past few years,China’s construction of urban underground rail transit has increased,and the structural safety of subway tunnels has become increasingly prominent.Numerous diseases will develop in tunnel lining structures as a result of the complicated geological environment of the subterranean due to soil pressure and dynamic load.In order to analyze the line’s force during operation and to correct the unfavorable situation,it may ensure the line’s safety.The two line subway tunnel’s lining structure’s power response properties,which affect the power response of the lining rigidity to the structure,are examined in this work using the method of combining theoretical analysis and numerical simulation with Jinan subway tunnel.The following are the key commercial and research findings:(1)The vibration load generated by the train moving to the music was simulated by the excitation pressure function based on the interaction between wheel and rail during train operation,combined with the parameters of Jinan Metro vehicles.The dynamic finite thing model was mounted in accordance with the requirements of the time’s geological conditions and design specifications.By contrasting the outcomes of the numerical simulation with those from earlier research,the model’s correctness is evaluated.(2)Calculations are made on the tunnel lining structure’s dynamic response to the vibration load brought on by a single train’s operation.The results of calculations for typical structural positions are retrieved at the same time as various working circumstances are designed in accordance with the lining thickness,concrete strength grade,and circumferential reinforcement spacing of secondary lining structure.Comparing and evaluating the influence that various parameters have on the tunnel lining structure’s dynamic reaction.The findings indicate that the bottom of the inverted arch is where the lining structure’s highest acceleration and displacement occur,whereas the foot of the arch is where the peak dynamic stress occurs.Tensile strength plays a major role in controlling structural damage.The dynamic response of the structure increases with lining stiffness,and growth rate reduces with lining rigidity.The impact of lining rigidity on the dynamic stress of the structure is more pronounced as concrete strength increases.(3)Calculations are made regarding the tunnel lining structure’s dynamic response to the superposition of vibration loads brought on by train intersections,and a comparison is made regarding the degree to which the change in lining rigidity has an impact on the dynamic response of typical positions on the left and right sides of the tunnel lining structure.The findings indicate that the dynamic response peak value difference between the structure’s left and right sides decreases as lining stiffness increases.The differential in vertical displacement between the structure’s left and right sides can be successfully decreased by adding reinforcement to the secondary lining concrete structure.(4)On the groundwork of the calculation outcomes of the dynamic finite factor model,the check samples are designed orthogonal,BP neural community and GA-BP neural community fashions are hooked up respectively to predict the primary parameters of the structure,and the prediction blunders of exceptional algorithms are compared.The effects exhibit that the BP neural community mannequin optimized via genetic algorithm has a higher prediction effect,and the neural community approach used to predict the primary parameters of the shape can furnish some instruction for the early diagram of the tunnel mission and make sure the protection of the working subway tunnel.