Research On Connection Mechanism And Design Theory Of Existing Orthotropic Plate With STC

Steel structure bridge has become the main structure form of long-span bridge in our country because of its superior mechanical performance,but some inherent problems of steel structure bridge are gradually exposed in the process of bridge use,especially the fatigue problem and pavement problem of orthotropic slab deck of steel bridge.In order to solve the above problems,orthotropic steel deck and super toughness concrete composite deck are adopted.The key technical problem of the light composite deck is the shear connection between the orthotropic steel deck and concrete.This paper focuses on this problem,the stress mechanism and law of interlaminar shear connection are studied,and some design suggestions are put forward,the research work includes:Firstly,this paper summarizes and compares the current theories of stress calculation of composite bridge deck,establishes a simplified calculation model of composite bridge deck,calculates the interfacial interlaminar shear stress of real bridge,and obtains the design theory and method of determining the shear connector according to the interfacial interlaminar shear.Based on the background bridge of Liaocheng Xinghua Road cable-stayed bridge across Tuhai River,a detailed spatial finite element mode l is established.The steel plate and concrete pavement adopt the treatment of complete bonding,that is,joint treatment.According to the analysis model,the distribution of interlaminar shear stress under the conditions of wheel load,overall lifting temperature and vehicle braking force is summarized and analyzed,and the variation trend of interlaminar shear stress is explored when the steel plate thickness,concrete pavement thickness,elastic modulus of concrete pavement and diaphragm spacing are changed.Based on the simulation results of finite element software,using the research results of short stud shear capacity,shear stiffness,load slip curve and other aspects,the short stud setting scheme of Xinghua Road bridge across Tuhai River in Liaocheng City is studied.The research scheme is compared with the original design scheme.On this basis,the spring element is used to simulate the shear studs,that is,to couple the vertical displacement of the corresponding node,to give the transverse and longitudinal stiffness,to impose the most unfavorable load,and to analyze the slip of the studs in the lane,above the inner web and above the middle diaphragm under the design spacing arrangement.The research shows that compared with the slip curve of single stud,all short stud are in the initial state of elastic work,which indicates that the existing shear stud setting scheme is too conservative and does not give full play to the she ar performance of shear stud,and will bring fatigue problems to the composite bridge deck.Based on the above results,the design scheme of short stud based on optimal stress is given.