Mechanical Analysis And Design Research Of Arched Linkslab For Multi-Span Simply-Supported Beam Bridge

Among the existing roads or municipal bridges at all levels,small and medium-span bridges account for more than 95% of the total number of bridges,and most of them are simply-supported beam bridges.In the design of simply-supported beam bridges,expansion joints need to be set at the ends of girders to accomodate the longitudinal deformation caused by temperature effects and vehicle loads.The number of expansion joint devices increases as the number of bridge spans increases,which has a great impact on the integrity of bridge superstructure.Expansion joints are placed at the connection points between two adjacent beams where they are subjected to complex forces.They could be easily damaged under repeated effects of external loads,which not only affects the appearance of the bridge,but also brings potential safety hazards to traffic,as well as increasing the cost of bridge maintenance and repair.The linkslab in simply-supported beam bridge eliminates the necesarity for setting expansion joints at beam ends.It makes possible that construction is simple,stressing is clear,project cost is reduced and driving comfort is increased.It is widely used in engineering.Due to its special location a linkslab is located at,complex stresses,lack of design method and poor construction quality,cracking occurs frequently.Under the cyclic effect of wheel loads,cracks will further propogate into potholes,seriously lowering the smoothness and durability of the deck and even the bridge safety.Based on the original traditional linkslab,this paper against a new type of reinforced concrete arched linkslab of simply-supported beam bridge.Based on mechanical theory,stress formula at weak parts under different loads and load combination conditions are derived;With the help of finite element software ABAQUS,stress distribution under different load conditions is analyzed,and influence of different parameters on linkslab is analyzed.Based on the analysis results,the reasonable value range for each parameter is determined.Finally,a simplified design method is proposed based on sensitivity analysis.The main work of this article is as follows:(1)The state of art of linkslab,its main structural forms and typical distresses are introduced;(2)The continuous structure of the reinforced concrete arched linkslab is simplified into the calculation model of hingeless arch,and the elastic center method is used to analyze the simplified model.The stress of the continuous structure of the arch linkslab under different load conditions is derived.Calculation formula and load combination,according to the stress distribution,load combination of the arch linkslab to obtain the maximum tensile and compressive stress of the upper and lower surfaces at the weak position of the arch structure;(3)With the help of finite element software ABAQUS,a fine simulation model is established for a traditional linkslab of simply-supported beam bridge,the stress magnitude and its distribution under different loads were analyzed,and the impact on the deck continuity is determined according to the stress analysis.The main factors of the force are combined with the main load factors to obtain the most unfavorable load combination and its location distribution that affect the linkslab;(4)Based on the original bridge of the project,the linkslab is transformed and designed as a continuous structure of reinforced concrete arched linkslab,and its refined simulation model is established to analyze its difference in different.The magnitude and distribution of the stress under the load and its most unfavorable load combination are compared with those of the traditional linkslab,and the superiority of the arch linkslab structure is judged;(5)ABAQUS is adopted to analyze the parameters of the arched linkslab structure and to determine the continuous reinforcement ratio of linkslab,the thickness of pavement,the material setting of the deck,the continuous span of the arch linkslab as well as the influence of pouring material on the stress of the arch linkslab.By the analysis results of each parameter,the main influencing factors of the linkslab are determined and a reasonable parameter value range is given;(6)Based on the above analysis results,a reasonable simplified design scheme is proposed for the arch linkslab,and an example analysis and theoretical calculation are carried out.