Study On Bearing Capacity Calculation And Reinforcement Technology Of Existing Railway Reinforced Concrete T-beam Bridge

With the rapid development of China's railways and the rapid development of high-speed railways,China's railway departments have realized that the original design concepts and design loads have been unable to adapt to the current railway operation requirements.After learning about the development of foreign railway operations and the investigation of domestic railways,the railway sector in China began to consider the requirements for durability of bridges after 2010 and developed a large number of new specifications.The original design load was adjusted.Nowadays,after decades of operational use,the experience of using bridges in operation shows that the key point of the bridge structure lies in the safety,durability,and economy of the bridge.The economic rationality is not only reasonable for construction costs,but it is the minimum for construction costs and inspection and maintenance costs.Early one-sided pursuit of low cost and neglect of durability has often resulted in greater economic losses and left us with bitter lessons..The lack of timely maintenance and reasonable reinforcement and repair methods for bridges has caused a large number of bridges to end their lives prematurely and caused great waste to the country.In the face of whether the existing railway bridges built in China that have experienced vicissitudes of life can meet the new normative standards,how much bearing potential there is and the lack of scientific assessment methods,there is no theoretical basis for the management of railways.The lack of an accurate method for determining the bearing capacity of disease bridges has made the reinforcement and maintenance unfounded,and there is no accurate and effective method for railway operation.Often a lot of maintenance costs,but have little effect.Based on the investigation of existing railway bridges in Gansu Province,this paper summarizes the long-term experience and lessons learned from the reinforcement of railway bridges.Based on the reliability theory,the bearing capacity of the bridge is studied and analyzed in terms of material properties,geometric dimensions,appearance defects,and load requirements.By comparing the old and new railway specifications,an analysis of the railway shows that the railway T-shaped girder bridge has a bearing capacity reserve under different load conditions.The vertical and lateral displacements and stress conditions of the bridge are calculated by the standard algorithm and the finite element method to evaluate the existing operation requirements of the existing 16 m railway T-beam bridge under medium-live load,ZKH load,and ZH load conditions.Using the load test method,targeted identification of the bearing capacity of the structure and normal use of capacity were made to assess the bearing capacity of the bridge.Combined with the existing research results of corrosion and sliding of reinforced concrete,a safe and simple evaluation method of bearing capacity was developed,which has guiding significance for the reinforcement and maintenance of bridges.Using the method of finite element modeling,the bridge disease was simulated and compared with the actual test results to obtain a more accurate finite element model.The finite element model was used to test the bearing capacity evaluation method and the reliability of the simple evaluation method was verified.Finally,using the established finite element model to compare the existing common maintenance methods of the existing railway concrete T-beam bridges,combined with the results of the structure reanalysis,testing and status assessment,the bridge maintenance countermeasures analysis,through comparison for the site The actual bridge maintenance reinforcement work provides theoretical basis and guidance,and formulates scientific and reasonable bridge maintenance and maintenance countermeasures.