Mechanical Properties Analysis And Research Of Large Span Self-anchored Suspension Bridges With Steel Box Girders

Self-anchored suspension bridge is very popular in engineering practice in recent years beacause it’s obvious abilities of carring loads,excellent shape and fitting for many site situation is reasonably high.The span length of the self-anchored suspention bridge is limited in engineering because the stabilities problem becomes outstanding with the compress force in girdrs and columns.In this paper the main static mechanical characteristics for self-anchored suspension bridges are analyzed based on an engineering case in Chongqing City of China.Research outline of this paper is listed as follows.1.Analysis of completion state of self-anchored suspension bridge is presented first.It is the base of studing other mechanical characteristics for self-anchored suspension bridges.In this paper the authors presented the inverse iteration to give out the completion state of the suspension bridge.2.Static mechanical computation of self-anchored suspension bridge in service is made.Firstly,four limit conditions of vertical loads distribution are figured out based on the influence line theory with vehicles and passengers as moving loads.Secondly,other loads including self-gravity and wind are added to analyze the static performance of bridge cables,tower and girder.3.Research on global stability of self-anchored suspension bridge is mainly done.During the completion and in-service state,the stiffening girder and tower of self-anchored suspension bridge are in total compression state.Moreover,the horizontal wind load and one-side eccentric moving load have obvious influence on the global stability of bridge.4.Study on local stability of self-anchored suspension bridge in terms of steel box beam with multi-scale FEM model are given out.Since thinwall steel box girder is widely used in stiffening girder for modern suspension bridge,it is the obvious problem that local buckling under the significant axial force for the bridge.Therefore,the stability of thin-wall steel box girder is necessarily taken into account.Herein,multi-scale FEM model is innovatively adopted to solve this problem.5.Some efforts on mechanical characteristics of hot-cast anchorage devices for bridge are made in this paper.Hot-cast anchorage devices for bridge is one of the most important parts in cable system,but its test is difficult and is rarely studied in details.Thus,some efforts are focused on calculating the stress distribution in hot-cast anchorage devices with Ansys Parameter Design Language(APDL).