Line eccentricity inspection on the bridge

Recent inspections have found that the eccentric value of the line on some bridges has seriously exceeded the limit, and there are potential safety hazards such as pressure feeding of the upper flange of the bridge (platform), instability of the bridge, and insufficient limits. According to regulations, the deviation between the center line of the line on the operating bridge and the design center line of the girder span should not be greater than 50mm for steel girders and 70mm for masonry beams. In the section where the driving speed is greater than 120km/h, the steel beams and masonry beams should not be greater than 50mm.

1. The survey data is filled in according to the format of the attached table, the result column has been entered for calculation, and the formula automatically calculates the result.

2. For bridges in double-line or multi-line sections, only the data from the outermost line of the bridge to the edges of the left and right girders are detected, and then the eccentricity is calculated according to the design standards; if the eccentricity exceeds the limit, the line spacing needs to be further reviewed.

3. Simultaneously check and measure the center distance of the main girder of the bridge. For multi-line bridges, the center-to-center distance of adjacent girder girders between two lines should also be measured.

4. For the straight part of the bridge, it is only necessary to check the abutment girder joints and the pier top in the middle of the bridge. If there is indeed an eccentricity exceeding the limit, then expand to all parts. Frame bridges do not need to be checked.

2. For double-line or multi-line bridges, only the data from the outside of the outermost track top of the bridge to the left and right edges of the beam body are detected, and the corresponding values are filled in the attached table, and the eccentricity is calculated according to the bridge design values.

3. Main beam center distance measurement: The distance between the centerlines of two beams can correspond to the distance from the bottom edge of the beam to the edge (such as the left edge of the left beam bottom to the right beam bottom to the left edge).