Study On The Adaptability Of Heavy Haul Railway Culvert In Service Reinforced By Corrugated Steel Plate

As an important part of the railway,culvert is the most easily neglected railway equipment in daily maintenance.The deterioration and mechanical performance of culvert structure directly affect the safety and stability of the railway.With the rapid development of China ’s ’ freight heavy haul ’ and the normal operation of heavy haul trains with large axle load,high density and long marshalling,the problems such as the aggravation of disease loss,insufficient bearing capacity and,insufficient bearing capacity and reduced stability,have become increasingly prominent.Reinforcement and reconstruction of culvert structures has become a key technology to ensure safety,and the use of scientific and reasonable reinforcement and reconstruction measures is the primary task.Based on a corrugated plate reinforcement project of a heavy haul railway,this paper takes more than 40 diseased culverts as the research object,and uses theoretical analysis,numerical simulation and experimental testing to focus on the corrugated plate reinforcement of heavy haul railway culverts.A series of problems such as parameter optimization selection,static and dynamic performance analysis,reinforcement method,construction technology,and disease treatment have carried out research on the key technologies of corrugated plate reinforcement of heavy haul railway culverts in service.The main work and contents of the paper include the following parts :(1)Taking corrugated plates with different spans and different waveforms as the research object,the numerical simulation method was used to study the stress and deformation of culverts reinforced by corrugated plates under the combined load of main force and additional force.The results show that with the increase of span and load,the stress and displacement of corrugated plates with different waveforms increase,and the stress and deflection of three corrugated plates with the same span decrease step by step.The average reduction rate of stress is about 20 %,and the average reduction rate of horizontal and vertical displacement is more than 30 %.The circular arc corrugated plate is better than the rectangular and triangular corrugated plate to reinforce the different span cover culverts,and the circular arc is the best waveform.(2)Based on the circular corrugated plate,the geometric relationship and design specification of corrugated plate section are studied theoretically.Based on the finite element model of corrugated plate with different span,wave height and wave distance,the influence of span,wave distance and wave height parameters on the deformation and stress of corrugated plate is explored.The results show that the performance parameters such as stress and deflection of corrugated plate increase with the increase of span and wave distance.Appropriate increase of wave height can not only improve the vertical stiffness of corrugated plate but also increase the ability of structure to resist deformation.The shear force is mainly concentrated in the chamfer position of the corrugated plate,which requires to avoid the stress concentration in the chamfer when assembling the corrugated plate.(3)Based on numerical simulation and dynamic test,the dynamic test of corrugated plate reinforced existing disease slab culverts of four 5 m-span heavy haul railways,the finite element analysis of the applicability of corrugated plate reinforced heavy haul railway slab culverts and the dynamic response changes of corrugated plate under the condition of speed and axle lifting are carried out.The dynamic performance indexes and recommended standards of heavy haul railway culverts under normal service conditions are put forward.The results show that the dynamic deflection and the dynamic strain of the steel bars of the four culverts are significantly reduced before and after the corrugated plate reinforcement,and the average reduction is more than 30%.The characteristics of the culverts are obviously improved after reinforcement.The difference between the dynamic response data of numerical simulation and dynamic test under normal operating conditions is about 7 %,and the finite element model and analysis method are reasonable.Under the condition of increasing train speed and axle load,the dynamic performance of corrugated plate meets the requirements of 80 km / h for 35 t axle load train.(4)Based on the engineering application of corrugated plate reinforcement of heavy haul railway disease culverts,the culverts of different disease types are divided and the causes of the diseases are analyzed.The dynamic test technology before and after the corrugated plate reinforcement of the cover culvert is further studied,and the corrugated plate is explored.What kind of disease type cover culvert reinforcement effect is better.The results show that the disease parts of heavy haul railway culvert are mainly concentrated in the roof,joints and wing walls,and the corrugated plate reinforcement method can effectively solve most of the disease types.The dynamic deflection and dynamic strain of the diseased culvert are significantly reduced before and after the corrugated plate reinforcement,and the vertical stiffness of the culvert is obviously improved,and the deflection and stress of the corrugated plate after reinforcement meet the design requirements.The reinforcement effect of corrugated plate on side wall is better than that of culvert top and joint,while the reinforcement effect of culvert top is slightly weaker than that of joint and side wall.