The application of optoelectronic set for measuring relative movements of rock blocks

Abstract

The article presents a new method for measuring relative displacements of rock blocks using the optoelectronic technique. Due to the fact that very precise optoelectronic devices are available on the market, it is possible to design various sets of measuring instruments. The proposed measuring kit consists of a set of lasers arranged in configurations identified by the project and CCD/CMOS camera, which is a measuring receiver. The measuring set designed and developed by the authors of the paper can be successfully used to monitor the relative displacements at short distances e.g. of rock blocks and monadnocks, in the cave corridors, in adits and water dam galleries. This method is based on angular intersection accomplished with laser beams, which are recorded by the CCD/CMOS camera. The tests were performed in 3 cycles for the following distances between the transmitter and the receiver: 38.5 cm, 78.0 cm and 153 cm. The obtained results of the measurements were subjected to statistical analysis based on the test: Student's t and F Fisher-Snedecor. Initial research and experimental works with a prototypical measuring set carried out by the authors in the laboratory enabled to determine the simulated displacements with the measurement accuracy better than ± 0.06 mm (about 1 pixel). ARTICLE INFO Article history: Received 1 December 2014 Accepted 9 February 2015 Available online 2 March 2015