Analytical Solutions To Internal Forces Of Shield Tunnel Lining Under Rayleigh Wave

With the rapid development of China's economy and the rapid expansion of the population, the pace of infrastructure construction is accelerating. Development and utilization of underground space is an important part of the modern social infrastructure. Because of its safety, speed, disturbance and less noise, shield-driven tunneling method has been widely used at home and abroad. Although underground structure, such as tunnel, has better seismic performance, they have been severely damaged during several large earthquakes in the history. Thus, it has paid more and more attention to the seismic design of underground structures.In recent years, the numerical method has been widely used due to the rapid development of computing technology. However, numerical analysis cannot express the key factors about the forces of structure in explicit form. This is not conducive for the concept design of the structures. Therefore, the analytical method for seismic analysis of underground structures still has a special meaning.In previous seismic studies of shield tunnel lining, the effects of the joint are rarely taken into consideration, and, in most cases, only the influence of S wave or P wave have been considered. It is also relatively rare that studies on the analytical calculation of internal forces of shield tunnel lining which is excited by Rayleigh wave.In this thesis, the equivalent continuous model has been used to consider the effect of the joint which weakens the overall stiffness of shield tunnel lining. Then, the shield tunnel is equivalent to an elastic foundation beam in the longitudinal direction and is equivalent to a homogenous ring in the transverse direction. Then, the equivalent stiffness of lining has been deduced by the mechanic method.Secondly, based on previous studies, the analytical expressions are derived for the longitudinal and lateral internal force of shield tunnel lining which is excited by Rayleigh wave.Thirdly, the longitudinal and lateral equivalent stiffness of shield tunnel are calculated by the way of example calculation, considering different periods of Rayleigh wave and different conditions of surrounding rock. Then the maximum internal forces of lining structure are calculated under various conditions. And several conclusions are found which are useful for the seismic design of shield tunnel.Finally, the main work of this thesis are summarized, and the future work to be conducted is pointed out.