Vibration Mitigation Design Of Low Tower Cable-stayed Bridge On The Basis Of Seismic Response Analysis

Low tower cable-stayed bridge is a new type of bridge which was developednearly30years. Its mechanic characteristic lies between continuous beam bridgesand cable-stayed bridges. With the earthquake happened in recent years all over theworld, especially the WenChuan earthquake of China in2008, it has brought hugeeconomic losses and a large number of casualties, therefore it brings us a bitter lesson.In order to reduce the earthquake disaster, people pay more and more attention to theseismic design of structure. In the field of bridge, the scholar fully understand theperformance of the traditional bridge type, but with regard to low tower cable-stayed bridge,the study of the seismic performance and the vibration mitigation design is not much, alsoneed to be further explored.The main content of this paper include:(1) This paper briefly introduces the structure characteristics and mechanicalproperties of short tower cable-stayed bridge, meanwhile discusses the long-span bridgeseismic design method and summarized the bridge seismic response analysis method andreduce isolation bridge basic theory.(2) On the basis of the basic theories, this paper selects a low tower cable-stayed bridgewhich has a twin towers and a single cable plane as the background bridge. We use the finiteelement software Midas Civil2012to study the Analysis of dynamic characteristics of thebackground bridge.(3) In order to understand the seismic response analysis of the bridges, this paper usesresponse spectrum method and dynamic timing analysis to study the seismic response ofbackground bridge under the E1earthquake. At the same time, the calculated results arecompared. Response spectrum method is to use the standard spectrum curve of accelerationresponse spectrum, it respectively input to the bridge from three directions and research theseismic response, the directions contain longitudinal，lateral and vertical. We also study theThree-way combination. The dynamic timing analysis method choose three seismicacceleration curve, there are E1Centro curve, Taft curve and Artificial wave. Finally wecompares the calculation results of the two methods above, compare the advantages anddisadvantages.(4)This paper explains the reason for the choice of reduce isolation measures andintroduces the Distribution of the isolation device. We use the software to simulate the LRBand analyse the influence of LRB in seismic response.