3D DIGITISATION application example

Deformation Measurement of a Stone arch Bridge with laser scanner By comparing scans of a stone arch bridge in the unloaded and loaded states, the deformation of the bridge is measured. The laser scanner Surphaser delivers submillimeter accuracy and a measurement noise of only 24µm.

Report about the deformation measurement of a stone arch bridge by using a laser scanner

The contractual behaviour of a stone arch bridge shall be determined with a load test. The train bridge is loaded with up to 6MN (600 tons) which matches 6 locomotives. 3D scans of the whole bridge underside and their supports are acquired with the laser scanner Surphaser.

The comparison of the 3D coordinates of the unloaded and loaded state measures the deformation of the bridge with sub millimiter accuracy at about 5 millions surface points. Figure 1 shows the underside of the bridge with the laserscanner Surphaser in front of the bridge. The load is applied at the shown 4 vectors.

Figure 1: Laserscanner Surphaser at 3D scanning of the bridge underside.

Figure 2 shows the color scaled deformation field (top view) of the bridge at a load of 4MN. Because the load is applied only on one of the two rails and only of one half of the bridge span the deformation field is unsymmetrically. The maximal bending is about 6mm at a load of 4MN.

Figure 2: Color coded deformation field (top view). The color scale shows the deformation in millimeter.