The Dynamic Response Of Close Crisscross And Overlapping Tunnels Under Subway Load

With the continual development of the scale of subway, the close quarter's tunnels in subway will appear inevitably. Based on the main theory of the interaction between tunnel structure and rock, this paper uses ANSYS to establish finite element models to study the dynamic responses to train load. According to the characteristics of train vibration load, this thesis simplifies the train-track system vibration. The simulation of train-track system vibration by computer model provides the excitation loads. Elastoplastic material DP is used to simulate the soil and linear elastic model as tunnel structure。This paper also uses ANSYS to calculate dynamic responses of left-right parallel close quarters tunnels under the dynamic load of single train and both trains; then reinforced tunnels are also calculated later.Some useful conclusions on the influence of dynamic load to surrounding tunnels are obtained, to what degree reinforced tunnels respond to dynamic load is obtained through comparasion. The dynamic responses under the consideration of different work conditions are discussed in the thesis which includes acceleration response , displacement response, moment, shear, axial force. These data are discussed and summarized so that the response curves of displacement and acceleration are obtained; the directional distributions of internal force are also obtained. These conclusions are of leading significance to both design and construction.The three-dimensional elastic dynamic FEM calculation mainly studies the left-right parallel- up and down close quarters tunnels section;a FEM model is constructed to study the dynamic response of tunnel under two load situations: single file -dynamic load, meet -dynamic load. Some useful conclusions have been obtained.