Study On The Dynamic Characteristic Of The Shield Tunnel With Complicated Space And Structure Morphology Train Under Vibration Load

With the rapid development of high-speed railway, there is a large number of space-cross tunnels and structures of space-cross tunnel.Thanks to the high security,high efficiency,high degree of automation and low disturbance to the surroundings of the shield method construction, a great quantity of space-cross tunnels and structures of space-cross tunnel are space-cross tunnel constructed through shield method, there are also numbers of cross structures, such as, transverse passage-way,ventilating duct, starting and ending Shafts, pump house and main structure of shield tunnel, connected by shield tunnel. On that account, the research is carried out on the study of dynamic characteristics of the shield tunnel in complicated space and structure morphology under vibration load of train, based on the construction of the ShiZiyang shield tunnel in high-speed railway which from Guangzhou to Shengzhen to Hong Kong. The main research is about the study of dynamics response characteristics of space-cross tunnels and structures of space-cross tunnel(represented by the transverse passage-way structure) under vibration load of train of different speeds and different surrounding rock classifications. The main research work and achievements are as follows:The generation mechanics of vibration load of train of different speed were studied, the mathematical expression of vibration load of train under different speed were analysed. The factors that influence vibration load include wheel weight, running speed, riding comfort, undulatory wear and so on, which are the factors of both vehicle and rail.The analytical theory and calculation method of the vibration dynamics of the train were stated, a new method of inflicting train load which is imposed on train wheel, varied alone with the spatial displacement and the time, under the circumstances that the train is running on specific speed is established, which is efficient on overcoming the disadvantages of the current method of inflicting train load,which is only inflict vibration load on the specific sector of the rail, resulting in the improvement of the analytical accuracy.The dynamic response of the space orthogonal shield tunnel under different train vibration loads and different surrounding rock classifications were studied. The characteristic of acceleration response,which should increase at first and keep stable for a while, then decrease, of each points in the lower tunnel was verified, while the train is running in the upper tunnel of the space orthogonal shield tunnel. The macro morphology of that the basic frequency of acceleration at orthogonal position performs significantly and controls time history of acceleration is revealed.The cross structure dynamic response of the connecting transverse pass way of shield tunnel under different train vibration loads and different surrounding rock classifications were studied. The position where the maximum principle stress and maximum speed in the transverse pass way occur, and the characteristic and the difference of dynamic response of the tunnel with train and without train, were verified. The changing characteristic of frequency spectrum of acceleration curve and the relative relationship of the maximum value of acceleration of the symmetrical points at both left side of left tunnel and right side of right tunnel are revealed.