Pairs Of Limbs Thin-walled Continuous Rigid Frame Based On The Deformation Of The Seismic Studies

More and more twin legged thin wall continuous rigid frame bridges appears recent years. Its length of main span and the height of piers broke new record continually. Whiletime bridge ductile aseismic design have been also put on the agenda. That only to research its elastic can't meet the needs of aseismic design. In this paper, fiber element and Elastic-plastic time history analysis were adopted to analyse the seismic response of the twin legged thin wall continuous rigid frame bridge based on the actual geological and construction conditions of Pinzhishang bridge located Gui Zhou. The seismic response analysis was based on deformation, which have great importance on enriching the aseismic research , giving reference to the aseismic design and enriching the method of bridge aseismic analysis. The major work has been done as follows:(1) A methord of seismic analysis which is based on structure deformation and practised by fibre element and Elastic-plastic time history analysis was put forword.(2) The ductility of the pier under the monotone load and the hysteretic energy dispassion under cyclic reversed lateral loads were studied. The results show that the concrete compression strength, diameter and strength of the main reinforcing steel , axial pressure ratio, stirrup have influence on the curvature ductility; the apbality of the hysteretic energy dispassion increase with the ductility raising.(3) The elastic-plastic dynamic response of twin legged thin wall continuous rigid frame bridge under the earthquakes transverse to bridges and parallel to bridges were analysed and the position where plastic hinge appears were figured out according to curvature envelope curve, which can give reference to its ductile secondary design. The influence of design parameter, such as concrete compression strength, diameter of the main reinforcing steel, strength of the main reinforcing steel, stirrup and the height of the pier, on seismic response were discussed.(4) According to the caculated result of the pie's dutility and time history analysis of the bridge, some suggestion to improve seismic design was given.