Observation of extensive mass movements in the Lipica II quarry with an EL beam displacement sensor

Abstract

It is not only that humans are playing with the environment, giving the quarry a bad external image, nature also returns a blow into the internal mass movements by decreasing the safety parameters of the room-and-pillar excavation. This paper presents the analytical methods used to observe the individual parameters in the context of monitoring the safety pillars and the deformation of the discontinuities in the underground excavation in the Lipica II natural stone mine. To monitor movements and deformations, the EL-beam gauges are installed on the surface of the safety pillars. The observations used in this case study are represented by two vertical EL-beam displacement measurements, acting as one year-long time series. Using ARMA modelling, we analysed the differences between the measured and predicted values of El-beam displacements. The obtained predictions of the displacements, their negligible effect on the measurements themselves, and the absence of any trends in the calculated differences, proves the feasibility of the applied prediction model. A longer observation period would allow predictions of possible seasonal characteristics of the time series, while the development of the automatic responding monitoring system, triggered by the warning events, will improve the reporting system for the sudden changes in the smoothness of the predicted values. Danijela Ignjatović Stupar International Space University 67400 Illkirch-Graffenstaden, France E-mail: danijela.stupar@isunet.edu Andrej Kos