How do you calculate the camber?
Magnet rod suspension process The magnet suspension is a fine wire of 0.5 m, fixed on a magnet at one end and a 0.5 kg weight on the other end. Install a position can be adjusted in the thin steel of 300 mm steel ruler, with a special insulating rod magnet adsorption to the girder under cover or i-steel rail under the surface. Then choose three measured points on both ends of the girder and beam, read through the set up on the ground level by magnet hanging on a numerical scale, so as to calculate the girder across the camber values. The value of the main beam span of the main beam is equal to the high value of the cross-medium height, which is the height value of the cross, and the higher value of the upper end. The steel plate is attached to the fine wire, and the result is an upper arch when it is positive and vice versa. This method can be used to detect the arch degree of the main beam, the method is simple, the result is accurate, save time and energy.
Hook rod suspension process Hook hanging scale method is to 300 mm steel feet upside down on the hook, to start the car (electric hoist) along the i-steel orbit, through set up on the ground level, in turn, acquisition girder elevation value of each point. It then calculates its arching value. This method of measurement error is large, and sometimes the opposite is possible. Factors that affect measuring precision is: the car wheel radius error and rail tread shape error and the car three legs will reflect on the elevation values directly, the acquisition of the elevation values are not real, finally calculate the camber of the value is not accurate.
Wire method Wire method requires three inspectors to climb to the crane girder, made from 0.5 mm to the end of the fine wire fixed to one end of the main girder (steel wire through the cover plate on the contour block), on the other side and the main girder at the other end of the 15 kg spring balance. Then take the measuring point, measure the vertical distance of the steel wire to the surface of the main beam, and then calculate the arch value. There is big limitation in this method and testing staff to work in high risk, applies only to part of the box type double beam bridge crane girder camber test, and is not suitable for single girder bridge (the door) crane and box with skirt plate into the double beam bridge crane girder camber of detection.
door) crane girder bridge deflection testing in the bridge (the door) crane safety technical inspection, the girder camber detection is an important content. The jb1036-82 (general bridge crane technology condition) stipulates that the main beam is the span of the middle of the bridge, F = L (0.9-1.4) / 1000. The maximum arch should be in the L / 10 range in the middle of the span. The current methods of detection are traditional tensile steel wire method and the current suspension method, as well as the magnet suspension rule.
