Complex System for Earthquake Prediction and Protection of Gas Installations

Abstract

In order to prevent explosions and fires caused by the ignition of uncontrolled gas leaks from damaged pipes following some devastating earthquakes, a complex system for earthquake prediction and protection of gas installations has been designed. The designed system ensures both the acquisition of data on local precursor parameters (evolution of radon emanations, evolution of earth's crust temperature, etc.) and local intensities of seismic events. Their transmission for processing to the national seismic dispatcher, thus contributing to a better knowledge in the earth physics field and implicitly to increase the accuracy of seismic predictions as well as 3D measurement of the local intensity of tectonic movements. In the case of seismic events with dangerous local intensity (above a pre-imposed, programmable threshold) the control signal is generated for the closure of gases by specialized aquatics (electrovalves mounted in front of the gas regulation/measurement block of the protected buildings). The system also ensures the take over and display of the information package about the state (closed / open) of the electrovalves mounted in front of the gas regulation / measurement block of the protected buildings. The 3D vibration transducer and the temperature transducer for the data acquisition system are mounted in a 40 m deep drilled well and the radon one on the surface (in the protection and visiting chimney of the well with transducers). Representative images regarding the realization/implementation of the system are presented. Compared to the known alert systems, the designed system requires little space for implementation and provides a number of advantages, such as: providing information on the evolution of precursor parameters of seismic movements in a given locality to the national seismic dispatcher, the level of knowledge in the field of Earth physics and the predictability of earthquakes; local validation of the intensity of tectonic movements in 3D and automatic closing in real time, without human intervention, of the gas connections in case of exceeding a pre-established dangerous threshold; revention of explosions and devastating fires following the damage of gas installations due to major earthquakes in a given locality (where the system is implemented), especially in public institutions, schools, boarding schools, hospitals, old people's homes, etc.

Implementation of a Radon Monitoring Network in a Seismic Area

“…The results are presented in Figures 7 and 8. In order to have a real-time response and an acceptable error, the equipment was programmed for 3 h for SARAD and 2 h for AER + C (Figure 5 (16), Figures 6 and 7).…”

“…In some cases there were only radon evaluation campaigns, such as at the Chiurus, Agigea, and Magurele stations (the last two are not in the Vrancea area). We also chose a reference location for radon monitoring in a less seismic area, Râmnicu Vâlcea RMGVdd, where the detector was positioned near a borehole in a specially arranged space [16]. The first tests were performed by positioning the radon detector in the ground, at a depth of 1 m in an enclosed space.…”

“…222 Radon in Bisoca, equipment AER + C; (2) 222 Radon in Bisoca, median filter; (3) 222 Radon integrated in Bisoca, STA/LTA detection anomalies (red points); (4) STA/LTA algorithm applied on 222 Radon in Bisoca, detection anomalies-red points; (5) ±2*Standard Deviation algorithm applied on 222 Radon in Bisoca, detection anomaliesred points; (6) Mw magnitude; (7) Neq/t, number of earthquakes within a time interval (7 days), the frequency of earthquakes; (8) 222 Radon integrated in Plostina, STA/LTA detection anomalies (red points); (9) Swarms of earthquakes.AER + C does not support a permanent USB port connection. For this reason, a relay operated through another serial interface (Figure5(16)) was used, which activates the USB port when data are requested.…”

The Results and Developments of the Radon Monitoring Network in Seismic Areas

“…The only monitoring station built specifically for this purpose is located in Râmnicu Vâlcea (Electrovalcea SRL site) (Figure 3, RMGVdd in Tables 1 and 5). More explanations can be found in [28]: 'According to Figure 3, the vibration transducer SV is mounted between glass beads PS in a drilled well PF 40 m deep and D-PF diameter Φ 350 mm. For the SV protection and of the ST temperature sensor, they are mounted in a PVC protection tube with a diameter of d-TPVC Φ 120 mm.…”

“…Figure 3. Installation of radon and acceleration sensors in a 40 m deep borehole [14].The description of Figure3according to the patent application "OSIM a 2020 00500 10 August 2020"[14] and the article[28] is as follows:PF -Borehole, 40 m deep; D -Diameter between 300 and 500 mm; SV -Vibration sensor (triaxial accelerometer); PS -Glass balls for fixing SV; ST -Temperature sensor; T PVC -PVC tube; C -PVC cover; P -10-30 mm gravel that ensures the diffusion of radon from the bottom of the well to the SRn radon sensor; SRn -Radon sensor mounted in the CV visiting space made of reinforced concrete;…”