Laser Measurement of Building Vibration and Displacement

Abstract

This paper considers four laser systems used by the Building Research Establishment (BRE) to investigate the behaviour of structures. Lasers enable remote measurements of vibration and displacement to be taken where access to a structure is difficult or where fire, explosion or structural collapse creates a hazardous environment. Each system will be described, and its use illustrated using measurements taken on real structures.The four systems are:1. Laser Interferometer: This is used to measure the velocity of vibration of a structure under ambient loading.2. 3D-Laser Survey System: This is used to track the movement of any number of targets on a structure under load.3. VHS Laser System: This is used to measure displacement of a target moving at high velocities.4. Tracking Lasers: This is used to track the angular displacements of a target.