What are the methods and techniques for repairing and reinforcing bridge bearings?

In the construction process of leveling steel plates for bridge supports, the placement method needs to be flexibly selected according to the longitudinal and transverse slope design and construction conditions of the bridge. The core goal is to ensure that the bottom of the beam is in horizontal contact with the top surface of the support without gaps, in order to achieve uniform stress on the support.

The following are specific placement methods and key points: 1. Common placement methods: Set concrete wedge blocks at the bottom of prefabricated slabs. Operation steps: Pour the concrete wedge blocks together with the upper hollow slab, and expose the beam bottom 5cm from the support centerline, keeping the bottom surface of the wedge blocks horizontal. Applicable scenario: Leveling needs to be completed during the prefabrication of hollow slabs, and the prefabrication pedestal and template need to be adjusted. Advantages: Stable structure, tightly integrated with the beam body. Disadvantages: High construction accuracy requirements and low adjustment flexibility. Operation steps for setting leveling steel plates at the bottom of prefabricated panels: Set leveling steel plates at the support points of the prefabricated panel bottom, perform vertical and horizontal leveling, and expose the center of the steel plate 0.5cm above the beam bottom for adjustment. Applicable scenario: Steel plates need to be pre embedded during the prefabrication stage, and subsequently leveled by adjusting the position of the steel plates. Advantages: Easy to adjust, can adapt to certain construction errors. Disadvantage: Strict control of steel plate embedding accuracy is required. The operation steps for adding wedge-shaped leveling steel plates between the pre embedded steel plate and the support top are as follows: pre embed the steel plate at the support point of the prefabricated slab bottom, embed it at the bottom of the beam, and adjust the longitudinal and transverse slopes according to the bottom of the prefabricated slab. When installing the hollow slab, a wedge-shaped leveling steel plate should be added between the embedded steel  plate and the support top to ensure that the bottom of the leveling steel plate is in horizontal contact with the support. Applicable scenarios: Prefabrication of beams and slabs is convenient, but wedge-shaped steel plates need to be polished to match the slope. Advantages: High flexibility and adaptability to complex slope designs. Disadvantage: Additional processing of wedge-shaped steel plates is required, which increases costs.

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2、 The key construction points are to match the longitudinal and transverse slopes of the wedge-shaped steel plate with the designed bridge slope to avoid bearing bias or premature damage. If the height of the cushion stone is the same, use wedge-shaped steel plates with different thicknesses; If the height of the cushion stones is different, use leveling steel plates with the same thickness. The horizontal contact leveling steel plate must be in horizontal contact with the top surface of the support, without gaps, to prevent shear deformation of the support due to uneven stress. Use a spirit level to check if the leveling steel plate is completely level, ensuring installation accuracy. The steel plates and embedded steel plates under the fixed and connected supports should be connected by intermittent welding around the perimeter to ensure structural stability. Before welding, the surface of the steel plate needs to be cleaned to avoid impurities affecting the welding quality. The anti-corrosion treatment leveling steel plate can be rust proofed by hot-dip galvanizing, forming a dense anti-corrosion protective film and extending its service life. The anti-corrosion treatment must meet the design requirements to ensure durability in harsh environments.

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3、 Method selection is based on bridge design requirements: select the most suitable leveling method according to the longitudinal and transverse slope gradients. Construction conditions: Consider factors such as the ability to adjust prefabricated pedestals and the precision of steel plate processing. Cost and efficiency: Balance construction costs, schedule, and leveling effects.