| As a kind of short distance green transportation system,slow traffic system has the advantages of high flexibility,small space area,green,low carbon and environmental protection,and has broad development prospects in alleviating various ‘urban disease’.Therefore,the planning and construction of slow traffic system has been gradually paid attention to by some cities in our country,and non-motor vehicle bridge is one of the important structural types.Because the steel box girder structure has the characteristics of large bending and torsional stiffness,light weight and high strength,flexible disassembly and assembly and beneficial to protect environment,it fits the characteristics of non-motor vehicle bridge well.Therefore,for non-motor vehicle bridge,the steel box girder structure is a better choice.However,there is still a lack of design specifications and regulations for non-motor vehicle steel box girder bridges,which makes it difficult to achieve efficient and orderly design of non-motor vehicle steel box girder bridges.Therefore,this paper studies the concept design of the non-motor vehicle steel box girder bridge in view of the basic factors,disaster prevention design factors and two key factors of stability and fatigue by using literature comparison method and finite element analysis method.The main research methods and conclusions are as follows:(1)Through the contrast and analysis of current specifications and the related research results at home and abroad,the basic design requirements for non-motor vehicles steel box girder bridge is put forward,mainly includes: general requirements,bridge layout design requirements,the aperture of bridge design requirements,bridge clearance design requirements,the bridge linear design requirements,detail structural design requirements and ancillary facilities requirements.(2)In view of the wind load,earthquake load and ship collision,combined with the current domestic and foreign specifications and research results,the disaster prevention concept design of steel box girder bridge of non-motor vehicle under the action of three kinds of accidental loads is proposed.(3)Based on hot spot stress theory,the fatigue resistance of orthotropic steel deck of steel box girder bridge for non-motor vehicle is studied through response surface method(RSM)and finite element technology.Research shows that:1)Compared with the two loading modes of transverse double non-motor vehicles loading and longitudinal double non-motor vehicles loading,single non-motor vehicles loading is more unfavorable to the anti-fatigue performance of orthotropic steel bridge deck.2)For the details of the rib-to-deck weld,the most unfavorable section is near to the diaphragm;For the detail of rib splice weld,the most unfavorable section is the mid-span section between two adjacent diaphragms.3)The influence of the thickness of the deck,the thickness of the steel plate rib,the thickness of the diaphragm,the spacing of the diaphragm and the height of the steel plate rib on the anti-fatigue performance of the orthotropic steel bridge panel of the non-motor vehicle steel box girder is different,and the increase of the deck thickness can effectively reduce the fatigue stress of each fatigue detail.4)Non-motor vehicles load will not cause fatigue damage to orthotropic steel deck of box girder bridge.And the fatigue resistance of the detail of rib splice weld is the weakest,and its maximum stress range is 33.57 Mpa,reaching 57% of its constant amplitude fatigue limit.(4)The basic design principles and classical theoretical formulae for the elastic stability design of thin-walled steel plates are summarized,and the design suggestions for the local stability of orthotropic steel deck of non-motor vehicle steel box girder bridges are given by comparing and analyzing the provisions of various national specifications on compression flanges and stiffeners of steel box girder,including the size of the deck design suggestions,the size and stiffness of the compression stiffener design suggestions. |
PDF Full Text Request