Seismic Performance And Earthquake Disaster Mechanism Research Of Irregular Curved Bridge With High Pier

With the successful implementation of the western development program, a large number of irregular curved bridges of high pier had been constructed in the southwest mountainous. This kind of bridge structure with its severe irregular plan and elevation, making the complex structure internal force coupling, load transfer path is not clear, leading to severe earthquakes disaster. For irregular high pier curved bridge, seismic response mechanism complex, damage evolution law of the key component is not obvious, leading to the earthquake disaster mechanism analysis be complex. In view of this, it has been discussed of the seismic response of irregular high pier curved bridge structure, high pier static and dynamic stability, and high pier vertical seismic delay in this paper. In order to achieve multi point excitation test using a single shaking table, the shaking table expansion system also be studied. In this paper, the following research work is carried out:1. Based on the basic principle of structural dynamics,in order to achieve the purpose of multi point excitation experiment for single shaking table, and the concept of the extended system of earthquake simulation shaking table is proposed. According to the working mechanism of the extended system, the theoretical analysis model is established for the one-way and multi direction shaking table expansion system. Based on the multi point excitation theory, the dynamic equations of the extended system are derived, and the analytical solution of the dynamic response of the extended sub station is given. Developing the one-way expanded system, the experimental study of the one-way expanded system shaking table is carried out, and the feasibility of the multi direction system is verified by a numerical example.2. According to the dynamic test similarity theory, design and production scale ratio of 1:20 reinforced concrete high pier curved bridge, and carried out the seismic simulation shaking table test. Through the analysis of the dynamic test structure feature point dynamic parameters, combined with finite element simulation, researching the seismic response effect of the high pier curved bridge structure, discussing the change regularity of the basic dynamic properties of the structure, establishing the of earthquake catastrophe model of this kind structure, to explore the developing regularity of crack and damage states of high bridge pier.3. By using the seismic simulation shaking table expanded system, achieing the multi-point excitation test for irregular curved bridge structure of high pier. By considering the local site effects of different seismic wave, combined with numerical results of seismic simulation shaking table test, analysis of irregular seismic dynamic response rules of high pier bridge load model in multi point seismic structural feature points, the index system of structure seismic response has been estabilshed.4. Based on the concept of friction sliding isolation, two kinds of working states of friction sliding isolation rubber bearing are analyzed, the relationship of force displacement curve is established, and the calculation method and energy dissipation mechanism are discussed. To set the friction sliding bearing of irregular curve bridge for shaking table test, analysis of different site, different intensity earthquake waves of different height of piers isolation effect, the rules of the high pier curved bridge structure of friction sliding isolation mechanism has been researched.5. Based on the plane section assumption, By considering the high bridge pier displacement deformation of the geometric nonlinear effect, establishing elastic bending rod vibration control differential equation, using variable step Runge-Kutta method analysis the high pier dynamic response under the of random seismic loading, combined with the B-R criterion,dynamic steady state of super high pier has been assessment, and establishing the computation method for the super high pier dynamic instability critical load and steady time.6. Based on the analysis of the relationship between the rotation angle ratio of the elastic center rod, combine with the angle recursive method, the unstable state equation of the structure is established. A recursive formula is presented to calculate the overall stability of the bridge with the lateral displacement, lateral displacement and double leg thin-walled high pier.7. According to the classical beam theory, combined with the relationship between the element node displacement and the internal force, the transfer relationship of the state vector of the typical bar element is constructed. According to the principle of d’Alembert, established the recursive formula of particle model of the state vector,put forward the transfer matrix method of variable section analysis element. According to the discrete time series of the structure dynamic analysis, derivation the transfer relationship of node state vector, the variable section element analysis transfer matrix method is established. Through the research on the vertical transmission of seismic wave in high pier, the seismic response regular of the bridge structure under the vertical time lag effect of seismic wave was analyzed and discussed.