Study On Seismic Behavior Of Single-cable-plane Suspension Bridge

With the rapid development of the economy and society,the safety of bridge structure is of great interest.The world has not yet predicted and controlled the technical means of earthquake in advance,and can only start from earthquake prevention.Therefore,studying the seismic performance of bridges is the focus of the engineering community,and it is also the top priority for earthquake prevention and disaster reduction research.Recently,single-cable suspension bridge has gradually become the darling of urban landscape bridge because of its simple modern and beautiful atmosphere,and it has been favored by engineering circles.The structural characteristics of the single main cable of this bridge are outstanding and the force is more complex than that of the traditional suspension bridge.The structural characteristics of the bridge are more sensitive to the external forces of nature such as earthquake,wind vibration and other natural forces,as well as to the dynamic excitation such as the moving impact of vehicles in the course of operation.It is easy to produce large dynamic response.At present,there are few single-cable suspension bridges built at home and abroad,and the research literature on anti-vibration is also very few.There is no detailed regulation on vibration control of this kind of bridge in our code.Therefore,it is necessary to The seismic behavior of single cable-plane suspension bridge is discussed in depth.In this paper,based on a single cable plane suspension bridge in Chongqing,the vibration characteristics and seismic response characteristics of a single cable plane suspension bridge are studied by means of response spectrum and time history analysis with finite element software,and the corresponding seismic mitigation measures are studied according to the response results.The following conclusions have been reached:1.Taking the Hechuan single cable plane suspension bridge with a main span of400m as an example,considering the pile-soil effect will generally reduce the natural vibration frequency of the structure,and considering the effect,the seismic response of the structure is increased.In seismic research,the effect of pile-soil interaction on seismic response analysis of single cable plane suspension bridge structure should be considered.2.The internal force and displacement of the structure obtained by time-history analysis method are generally larger than those obtained by the reaction spectrometry.When the seismic design of the single-cable suspension bridge is carried out,the reaction spectrometry can do a reference analysis,in order to improve the safety factor of the bridge seismic design,the dynamic time history analysis of the consistent input must be carried out.3.The viscous dampers with damping coefficient 6000kN/(m/s)~n and velocity index 0.4 are the best for this example,which can significantly reduce the longitudinal relative displacement of the tower beam and make a rapid vibration control response under the action of earthquake.4.The transverse bending resistance of the single cable plane suspension bridge can be improved by using gradually separated main beam,and the torsional performance of the single cable plane suspension bridge is better than that of other forms of main beam.