Research On Influence Of Heavy Load Railway On Existing Culvert And Reinforced Culvert

Heavy-duty railway transportation has the characteristics of large volume,high efficiency and low cost,making it widely used in many countries and regions such as the United States,Europe,and South Africa.In the 1980 s,China carried out relevant research on heavy-duty railways,and gradually upgraded the original railways to improve China's heavy-duty railway transportation system.After upgrading to heavy-duty railways,parameters such as vehicle type and axle load have changed.What is the impact of these changes on existing bridges and culverts? It is necessary to clarify.Due to the small load of the design of some bridge structures,it may not be able to meet the requirements of heavy-duty railways,and it is necessary to carry out corresponding strengthening treatment.In this paper,the culverts of the Shuohuang Railway are studied as research objects.The main research contents are as follows:(1)Taking the seven reinforced concrete bridges and culverts of the Shuohuang Railway as the research object,the influences of parameters such as load axle weight and vehicle type on the mid-span deflection and steel strain of the bridges and culverts are analyzed.The results show that with the increase of the load axle weight,the maximum strain of the steel bar increases gradually.When the load axle weight is 300 kN,the maximum steel strain increases by 30%;in general,with the variation of the mid-span deflection.The law of steel bar strain is consistent;as the load axle weight increases,the safety reserve of the bridge and culvert structure gradually decreases.When the axle weight increases to 270 kN,the bridge or culvert less than 6m exceeds the design load.(2)In order to ensure the perfection of the heavy-duty railway system,it is necessary to take corresponding strengthening measures for the culvert structure that does not meet the bearing capacity requirements.In order to clarify whether the corrugated plate reinforcement measures are feasible,the phase model is established by numerical calculation software ANSYS to analyze the stress and deformation of the culvert under the action of heavy-duty railway.The research results show that under the action of heavy-duty train,the maximum principal stress of corrugated plate is 6.3MPa,which is much smaller than the allowable stress of steel.the working internal force is small,and the safety factor is large;the maximum deflection of the culvert span after reinforcement is 0.33 mm,the conversion of the live load to the span ratio of 1/18182 is much smaller than the normal reinforced concrete beam vertical deflection span ratio of 1/4000.(3)Taking a culvert as the research object,the corrugated plate reinforcement technology was used to strengthen the transformation,and the performance of the culvert before and after the reinforcement was tested.The results show that after the corrugated plate is strengthened,the strain of the mid-span steel is reduced by 30%;the maximum deflection of the mid-span is reduced from 2.10 mm before the reinforcement to 0.18 mm,and the strengthening effect is obvious.The strengthened culvert can satisfy the heavy-duty locomotive.(4)Taking a frame culvert as the research object,the corrugated plate reinforcement technology is used to strengthen the culvert.The test results show that the reinforced steel strain and vertical deflection of the mid-span of the culvert decrease a lot after the corrugated plates are strengthened,and the overall reduction is about 50%.The reinforced arch culvert can meet the normal operation of heavy load train.