Analysis On Mechanical Properties Of Existing Railway Ribbed Beam Bridge And Reinforcement Technology Research

The ribbed bridge is a common form of beams in the early railway construction in China.The main reason for its large number is that in the early days of the founding of our country,all aspects of the resources were relatively scarce.Ensure the normal use and operating conditions of the bridge,and the choice of ribbed section just meets these requirements.However,after several decades of operation and use,it was discovered that due to multiple effects of initial design,construction,and late maintenance,speed and load increase of the line,these bridges gradually experienced aging of concrete materials,corrosion of steel bars,damage to bearings,and structures during service.Diseases such as weakened resistance have laid a great hidden danger for the safety of the line.Therefore,it is a work to be solved to carry out the investigation of the ribbed bridge disease,analyze the damage mechanism,check the bearing capacity reserve of the diseased beam and propose effective maintenance and reinforcement methods.This article relies on the scientific research project "Research on the Evaluation and Maintenance Technology of Rib-Slab Bridges" to analyze the disease characteristics and causes on the basis of the field survey of the rib-slab beam bridges in Northwest China,and to study the beam bearing capacity through inspection and finite element simulation.It is affected by different diseases,and some effective and reasonable maintenance and reinforcement methods are proposed.The main research contents are as follows:(1)Through field surveys of ribbed bridges in the northwest region,quantify the degree of disease,analyze the causes of diseases,and summarize the law of diseases;and summarize the common bearing diseases of ribbed bridges and the influence of the eccentricity of curved beam bridges on the stress of the beam body.(2)Carrying capacity inspection of the T-beam external bridge deck susceptible to disease according to relevant regulations,and analyzing the feasibility of opening a heavy-duty train to calculate its safety reserve;at the same time,the beam body is horizontal The bearing capacity of the full beam under the failure of the diaphragm is checked.(3)According to the actual bridge experiment,establish a finite element model,calculate the bearing capacity and stiffness of the real bridge,compare the finite element calculation results,and verify the correctness of the finite element model;and use the finite element model to simulate the bearing void and the curved beam line bridge The bearing capacity of the eccentric lower beam provides comparative data for subsequent reinforcement and maintenance.(4)Discuss and analyze the repair methods for the common beam concrete and bearing defects of the current railway ribbed girder bridges,introduce the repair ideas,repair materials and construction procedures,etc.Finally,three reinforcement methods are proposed,which are calculated and analyzed using the finite element model The improvement effect of different reinforcement methods on the bearing capacity of the beam is provided,which provides a theoretical basis for the relevant reinforcement work in the future.