Design And Research On The Rigid Bridge With High Pier

The continuous rigid frame bridge with high piers is commonly built in China,because of its advantages on economy and construction. However, the problem of stability, in cantilever construction stage and in service stage, is very remarkable for the bridges with high piers. Based on the MaoJing Bridge in GuiZhou province, this thesis focuses on the stability of the continuous rigid bridge with high Piers during the construction of cantilever and the service stage. The main research work is summarized as follows:(1)First, the design characteristic of MaoJing bridge is introduced, some important problem is discussed, the geological and hydrological condition are also introduced. A lot of calculations are conducted in order to compare the mechanical performance of superstructure with different rigidity of pier. The last section type of pier are deduced.(2)First, the existing research work on the stability of high piers had been introduced. Then, the solution methods of the first type stability and the second type stability were summarized in this thesis and the main difference between them was discussed.(3)The local stability of plate is analyzed.(4)Taking MaoJing Bridge for example, based on the finite element procedure using software ANSYS, the spatial stability of high piers in all kinds of cantilever construction was studied, taking both geometrical and material nonlinearities of such structures into consideration. For geometrical nonlinearity, Updated Lagrangian formulations are adopted to derive the tangent stiffness matrix. In order to simulate the nonlinear behavior of the plastic hinge of the piers, the bilinear rotational spring element Combine40 are used in model. So the load-deflection curve can be got.(5)The geometrical nonlinearity of pier is compared by specification formula and the finite element program ANSYS. Results show that results deduced by specification formula are safer.