Three Dimensional Mechanical Property Analysis For The Continuous Rigid Frame Bridge With Long-Span And High Piers

Because of the strong adaptability of terrain, the maturity of design and construction technology, long-span capability and the reasonable cost, the continuous rigid frame bridge of pre-pressed concrete is widely adopted. With the constant development and application of the long-span and high piers continuous rigid frame bridge in our country, the corresponding issues have been researched and discussed deeply.The dynamic problems of bridge structures have always been cared for by bridge workers. It consists of two aspects: one is free vibration and another is dynamic response of the bridge structure. Combined with Xiatangkou Wujiang long-span railway bridge, its space model is created by shell element of ANSYS and three-dimensional beam element of SAP in this thesis. Firstly,its space free vibration character is analyzed by FEM method,and introduce the influence of the main parameter of structure for bridge's free vibration character.Secondly,the FEM model is analyze include static and transient-dynamic response time history analysis, and then a series of contrast analysis are done under the moving load. On the base of simulating the train pass the girder with speed of 10~80km/h of single line and double lines.According to the calculation, the following results can be obtained: the height of pier of bridge have most influence for free vibration of the bridge.In static analysis,the calculational results of vertical displacement of the model of SAP and the shell center of model of ANSYS is approximated. In transient-dynamic response time history analysis, the MAX of vertical acceleration increased with the increasing of train velocity,for the main section,the MAX of vertical acceleration in double lines is bigger than that in single line between once to twice.The rule about impact coefficient has increased trend with increasing of train velocity in section of middle of span.