Abstract. Bridges belong to critical structures. Therefore the geodetic monitoring of their stability should be performed during their operation. Correctly and qualitatively performed control over stability of the ready-built construction increases the term and the reliability of operation of the bridge and considerably increases the safety of its use. All over the world there is a tendency to increase the length of superstructures of bridges and to use widely the flexible constructions. This makes these structures even more sensitive to dynamic loads. Based on the concept of unfolding the laser beam in the horizontal plane, the methods and devices for measuring the polydimensional deformations of superstructures of bridges and over-bridges were developed. The article examines the methods and devices for measuring the polydimensional deformation of superstructures of bridges and over-bridges with the use of deployable optical laser systems for measuring the longitudinal deformation of superstructures and an ultrasonic sensor for measuring transverse deformation. The devices use lasers with continuous radiation of a beam of a certain wavelength. Optical collimators are arranged in series with the lasers. The spinner, for example, is an engine on the shaft of which there is a mirror or a prism with a reflecting face at an angle of 45° to the laser beam, or a rotating optical wedge, due to which the laser beam is deployed in a horizontal plane. All n sequentially arranged deformation sensors and an additional photodetector for the control of the deflection of the wire on which the ultrasonic sensor is installed, are made in the form of a line of elements of a certain length, and each photodetector has the same number of elements. Each element of the photodetector is made of a certain material that transmits a laser beam without any special interference. The devices can be used in the automated system of monitoring of the deformations of the bridge structure (ASDB), which will allow the quick control of their condition, displacements and deflections resulting from the external climatic influences, as well as the amplitude of oscillation of loads from the continuous traffic with non-cyclic long-term loading of superstructures of bridges and over-bridges.
Measuring system for monitoring the polydimensional deformation of superstructures of bridges and over-bridges
