The Stochastic Response Analysis Of Curve Viaduct Under Non-consistent Earthquake Function

The earthquake is a natural disaster that severely affects man's life. In the modern transportation system, especially in the municipal system, great span curve viaducts are more widely used. Because the earthquake responses of the great span curve bridges' are complex and distinctive, further studies on the characteristics of the curve viaduct's seismic response are becoming more significant.In the process of analyzing the earthquake-resistance, a key step is to determine the seismic excitation input. In the present seismic code, it generally uses the consistent seismic excitation input. At present the bridges' spatial sizes are getting bigger and bigger, it is a little rough to use the traditional computational methods. Under the multi-support input action, mechanics theory of the bridge structure is largely different from the consistent seismic excitation input. Therefore, it is necessary to study further the seismic response of the curve viaduct under multi-support excitation input. As for this problem, this thesis will do the analysis from the following aspects:1. Through the analysis of the computation theory of the curve beam bridge and the basic differential equation, the curve beam bridge's characteristic is analyzed and the calculation diagram of the curve viaduct structure is established. And three box-section curve viaduct's finite element analysis models are formed, which are considered from the frequently-used structural styles.2. The thesis also introduces the elementary theory and the analysis method of the random vibration, introduces in detail several kinds of commonly used models and the characteristic of the ground acceleration power spectrum density function, and determines the model's spectrum parameters reasonably. With the help of the ANSYS analysis software, it introduces the random vibration's elementary theory and the analysis process of bridges under non-consistent excitations, establishes the structure calculation models based on the traveling wave function and the spatial partially correlated function.3. Based on the dynamic analysis of the three kinds of analysis model of curve viaduct, the stochastic response analysis under both the consistent earthquake function input and the non-consistent one are put forward in the paper with the consideration of the traveling wave effect and the spatial correlated function. In additional, different influences of the responses to the curve bridge structures, which are due to the traveling wave function with different wave velocity and the different spatial correlated function, are deeply discussed.Because of the traveling wave function and spatial correlated function to the structure, it is believed that the influences to curve bridges are quite big. Furthermore, both the increase influences to the structure and decrease ones appear according to the influences with less strict regularity. Therefore, to the actual projects and its actual structure, the calculation model relied on the ground dynamic characteristic and parameter at the bridge site should be established associated with the analysis software and the reality responses can be got in order to tutor the construction. This thesis analysis and the conclusion may take the engineering design the contrast reference. In the end, some questions to study in the future are pointed out.