Research On Disease Assessment And Reinforcement Technology With Steel Crossbeam Of Hollow Slab Girder Bridge

Bridges,as a controlling project of national road construction,play an important role in civil transportation in countries with rapid economic development,such as China.Hollow slab girder bridge is widely used among different kinds of construction forms,as it is convenient for assemblable construction and relatively inexpensive.As a developing country,in recent years,China's national economy has been developing at a rapid pace as that of developed countries.Transportation development is also booming day by day.The vast majority of such bridges built in the early stages have been unable to meet the current traffic requirements.A variety of diseases continue to emerge,which has a serious negative impact on the safe operation of the structure.In view of the current operation and research status of hollow slab girder bridges,disease detection and analysis,technical status assessment and reinforcement technology of hollow slab girder bridge is studied in this paper.The main research contents and conclusions are as follows:1)Based on the summary of common disease types and generating mechanism of hollow slab girder bridges,disease characteristics and causes are analysed,and the significance of research on reinforcement technology of hollow slab girder bridge is clarified2)The theoretical methods related to the reinforcement calculation of hollow slab bridges are systematically sorted out,and the characteristics of the displacement increment of such structures in direct proportion to the load increment are utilized,based on the principle of equivalent stiffness and the theory of elastic plate,the calculation method of the lateral distribution influence line of this kind of bridge strengthened by steel beam is studied to give reasonable layout method,design process and construction control points.3)Disease detection technology,technology assessment technology and load test technology of hollow slab girder bridge are studied to give reasonable methods of appearance detection,technical condition evaluation,static and dynamic load test for hollow slab bridges,Application of this method in engineering practice is illustrated based on a viaduct along Shunhe River.4)A large number of finite element solid models are established to analyze the structural deformation of the original bridge and different reinforcement schemes,and the reinforcement efficiency of different reinforcement schemes is calculated and compared.Results of joint stress of original bridge and different reinforcement schemes show: the maximum principal stress of the hinge joint decreases significantly after reinforcement,which indicates that the steel beam reinforcement method has a better effect on improving the stress behavior of the hinge joint.Study shows: The larger the section size and the smaller the spacing of the additional steel cross-beam,the bigger the reinforcement efficiency is,however,with the continuous change of section size and setting spacing,the change range of post-reinforcement effect shows a decreasing trend,and eventually tends to be flat.In order to improve the economy and reinforcement efficiency at the same time,the equivalent concrete thickness of the steel cross-section should be close to that of the hollow slab structure of the original bridge,and the spacing of the steel cross-section should be one fourth of the span.5)Taking a bridge reinforcement project along Shunhe Viaduct as an example,the reinforcement scheme is designed according to the optimum cross-section size and setting spacing of steel beams,and the original bridge and reinforcement system are simulated and analyzed by using the special software for large bridges.The results shows: adding steel beams to reinforce such bridges can adjust the load-sharing ratio of each main beam and reduce the most adverse effect value,which ultimately achieve the purpose of improving the bearing capacity of the structure.