Analysis of the origin of Tangshan bridge bearing manufacturer What problems will be faced with the replacement and management of small and medium-sized bridge bearings

Bridge is an important part of highway, and the quality of bridge bearing replacement is directly related to the safety and smoothness of highway traffic. At present, the replacement and management of small and medium-sized bridge bearings face the following problems. The origin of Tangshan bridge bearing manufacturer is your explanation:

(1) Bridge durability: due to insufficient design considerations, reinforcement corrosion, freeze-thaw damage, alkali-aggregate reaction, chemical erosion and environmental impact., The bearing capacity of the structure will decrease with time. Especially when the concrete cover is exposed and the reinforcement is corroded, its effective sectional area will continue to decrease, making the bearing capacity of the structure rapidly decline and irrecoverable, and even the reinforcement will break in serious cases. When the residual bearing capacity of the structure is lower than the action load, the bridge structure may be damaged. Therefore, the durability of bridges caused by steel corrosion has become a very prominent and catastrophic problem.

(2) Fatigue problem: The materials used for bridges often contain small defects. Under cyclic loading, these tiny defects (microcracks and micropores) will nucleate, develop and combine to form damage, and gradually form macroscopic cracks in the material. If macro cracks are not effectively controlled, brittle fracture of materials and structures may occur. Fatigue damage is the core problem of steel bridge design. There are many cases of bridge collapse caused by fatigue fracture. Early fatigue damage is often not easy to be found, but its consequences may be catastrophic.

(3) Traffic volume problem: the traffic volume problem is getting bigger and bigger, and the bearing capacity of the old bridge can no longer meet the requirements of the new load level.

(4) Loose management: small and medium-sized bridges are widely distributed, difficult to track, diverse management forms, diverse bridge structures, and uneven maintenance technologies.

(5) Bridge overload: bridge overload is an objective phenomenon, which is very prominent in some sections. There are two situations: first, the old bridge built in the early stage is over-aged and overloaded; The other is the existence of illegally overloaded vehicles. The former is mainly caused by the change of design specifications, the increase of traffic volume and the development of heavy vehicles, which is inevitable. The latter is very common in highway transportation in China because vehicle users violate traffic laws and regulations to carry out overload operations. Overload will aggravate bridge damage and cracks, and even cause some structural damage accidents due to overload.

(6) Maintenance lag: small and medium-sized bridges account for 90% of the total number of bridges, which are large in number, widely distributed, difficult in supervision and large in maintenance investment. The situation is complex, especially for low-grade roads distributed in rural areas in remote areas, which lack necessary maintenance funds and technical support, and it is difficult to ensure the passage of bridges.