Study On Parametric Design Of Collapse-proof Systems For Simply Supported Girder Bridge

The unseating of bridge superstructure is one of the most serious earthquake damage ofgirder bridges. It is one of the most important topics to study the unseating preventionseismic measures for seismic design of girder bridges. Experts and scholarsat home andabroad have payed much attention to this problem during recent years， and manyachivements have been obtained. Collapse-proof systems is an important part of the dampingcomponents of the Beam Bridge，in domestic，the anti-drop-beam device is used as structuralmeasures，it is difficult to play a real anti-girder falling effect if the anti-drop-beam devicehas not been calculated and designed in the earthquakeThis thesis is based on the analysis of the unseating of bridge and its causes in nearly30years，introduced the development and current status of collapse-proof systems technology athome and abroad， studying the anti-seismic parameters of simplely supported girder bridgeand parameters of the restrainer. The following work is done：(1) On the basis of a large number of domestic and foreign literature，statisticed thebridges which had occurred girder-falling in earthquake， summarized the reasons for thegirder-falling phenomenon. Reviewed and summaried the components and research status ofcollapse-proof systems；(2) Studied the effect of restrainer to Miaoziping Minjiang Bridge Approach9#12#axis cross which had fallen girder in5.12earthquake by gradually increasing the input peakacceleration of seismic waves.(3) Studying seismic parameters (adjacent pier cycle ratio, bearing friction coefficient,the beam between the gap) of simply supported girder bridge at the longitudinal strongearthquakes，and studying their effects on anti-seismic behavior. Discussion has been madeon simply supported girder bridges seismic parameters basing on calculation results throughnonlinear time history method comparison studies.(4) Calculated simply supported bridge at longitudinal earthquake with finite elementsoftware. Getting the restrainer design parameters (stiffness and limit device limit deviceinitial clearance) effects on anti-seismic behavior of simply supported bridge.