Study On The System Of Strengthening Construction Of The Conversion Method Of Black Line North Bridge

Top flange type hollow beam(board) structure is widely used in the1990 s, Liaoning area of big bridge superstructure, the single hole span is 13 meters or 16 meters. Only in Fushun City, Liaoning Province, there are 129 bridges of this kind. The total span of 10,100 meters are large and medium bridges, accounting for 40.69% of big bridges number proportion(a total of 317 seat). After nearly 20 years of safe operation, the effects and limitations of design, materials, construction technology and other aspects of construction design, hinge joints cracking, cross section transverse joints and fulcrum cross section cracks, etc.. After the occurrence of the disease, although the upper structure load bearing function is still good, but the scope of single disease is not large, but in the whole bridge, the development will eventually affect the bearing capacity of the load, the threat of the use of bridge safety. From the economic and social aspects, it is impossible to achieve large-scale re construction, even if part of the conversion is very limited. Therefore, the bridge reinforcement and maintenance becomes one of the most effective solutions. And the research and practice of scientific and technical personnel have proved that using the new structural system to replace the existing bridge in service is not enough structural system, changing the original structure of the force, so that the original structure to reduce deformation can make the bridge in the stress and strain allowable range of security service. Therefore, system transformation is considered as one of the effective methods to solve this kind of bridge disease.The Liaoning Fushun Qingyuan Heida line Bei San Jia Qiao using system conversion method of maintenance and reinforcement construction, for example, briefly introduces the 16 meters simply supported hollow beam slab bridge reinforcement of the construction and maintenance. From the current situation and the causes of the basic situation, this paper introduces the principle and maintenance plan of strengthening the maintenance of the system transformation method. Using bridge expert to check the bending and shear bearing capacity of the bridge deck slab and the middle plate and to calculate the crack of the side plate and the plate in the limit state. This paper will explain the comprehensive exposition of the North Bridge reinforcement and repair of the construction of the link. In accordance with the first simply supported then continuous sequence emphatically from the top of the beam and plate rise, crack repair, reduction of CFRP cloth paste, corroded steel bars, anchorage construction technology, pier construction of cast-in-situ segment and beam end maintenance section, add diaphragm beam, hinge joint wet joint, bridge deck pavement, anti-collision on the medial wall of the maintenance and anti salt waterproof coating material and doped material application and template technology innovation etc. eleven aspects discusses the construction process. The first and second holes of the bridge are selected as the test objects, and the static and dynamic tests are done respectively. The test results are static load test stress and deflection check coefficient, which can satisfy the requirements of the identification method of the bearing capacity of the old highway bridge. The dynamic load test indicates that the natural frequency and damping ratio of the bridge are in the normal range. The bridge has been successfully achieved, and the system transformation method is effective and feasible, and it can be used as a kind of bridge reinforcement and maintenance in Liaoning area in the future to promote the application.