The Reinforcement Of Pier Foundation For Huangshuihe No.2 Bridge In Lan-qing Railway

The relationship between economic taking-off of China and infrastructure construction is closely. The development of bridge career is by means of this kind of situation, bearing the important task to keep smooth traffic. But some bridges built in the 60s and 70s of last century have reached 50 years. The specification requirements and environmental conditions compared to now there have been a great change. One is the speed of change, our country has experienced several big speed railway; the secondly, it is the change of train axle load, transport more frequently. Obviously, most bridges cannot be torn down, which can continue to use only after reinforcement assessment is qualified, so railway bridges reinforcement and maintenance has become the norm.In this thesis, based on K36+879 HuangShui River LanQing line 2# bridge reinforcement project, the bridge is located in the west of HeZui village of Honggu area, lanzhou city, HuangShui River downstream, which is one of bridges across HuangShui River on LanQing railway up line. Pile foundation scour testing found the bridge pier local scour is serious, and part of the bridge pier river line on the ground and bridge pier distance is less than the safe distance of the basement; in the state of bridge detection report, part of the bridge piers maximum amplitude exceeds maximum amplitude value, so maintenance is necessary.According to the K36+879 HuangShui River LanQing line 2# bridge disease situation, we discuss the typical cases of different waterlogging damage of bridges based on the study of bridge pier local scour at home and abroad, and conduct a study of the multiple factors causing the bridge pier foundation of the shallow foundation scour; And at the same time, this paper discusses the principle of the bridge reinforcement and strengthening method and find the reasonable reinforcement scheme according to the actual situation. According to the railway bridge gauge, the dissertation covers the structure of the static calculation, analysis and comparison before and after the reinforcement of the bridge under different working conditions, and proposes reinforcement scheme respectively. The reinforcement of bridge pier is checked, and the bridge dynamic characteristics include the measured natural frequencies, deflection beam body and the transverse amplitude of the pier, which all meets the specification requirements after reinforcement. Therefore, this research method is credible and reinforcement scheme is feasible.Through the study on the project for K36+879 HuangShui River LanQing line 2# bridge and the reinforcement, it has obtained the good social benefit and obvious economic benefit. This dissertation uses the existing specification to check the static analysis and test the dynamic characteristics of bridge actually, judging the running state of bridge safety or not, which gives an example for other railway bridge reinforcement and provides a certain basis for how the bottom of the old bridge pier’s conditions influence on the stability.