The paper describes the mechanism and design of the wireless device for activation of energy absorber for localization of blast energy in underground openings. The statistics shows that the greatest share of accidents with fatal results associate with explosions in coal mines due to aero-methane and/or air-coal media explosion. The other significant problem is terrorist or accidental explosions in underground structures. At present there are different protective systems to reduce the blast energy. One of the main parts of protective Systems is blast Identification and Registration Module. The works conducted at G. Tsu lukidze Mining Institute of Georgia enabled to construct the wireless system of explosion detection and mitigation of shock waves. The system is based on the constant control on overpressure. The experimental research continues to fulfill the system based on both threats, on the constant control on overpressure and flame parameters, especially in underground structures and coal mines. Reaching the threshold value of any of those parameters, the system immediately starts the activation. The absorber contains a pyrotechnic device ensuring the discharge of dispersed water. The operational parameters of wireless device and activation mechanisms of pyrotechnic element of shock wave absorber are discussed in the paper.
The paper describes the some results of experimental investigations of Electromagnetic Pulses (EMP) generated
during the explosion of hexogen charges in tunnels. The shape and duration of the signals in the range of the several
milliseconds were studied. The results obtained after experimental investigations can be used for establishing the criteria
for identification of explosions.
Experiments have conducted in the underground test opening of G. Tsulukidze Mining Institute. During
experiments, electromagnetic pulses (EMP) and optical signals, generated under explosion of condensed charges of
explosives in tunnels, were recorded simultaneously.
Considering the growing threat of terrorist or accidental explosions in underground stations, underground highway and
railway sections improvement of system for protecting people from explosions appears urgent.
Current automatic protective devices with blast identification module and blast damping absorbers of various
designs as their basic elements cannot be considered effective. Analysis revealed that low reliability of blast detection
and delayed generation of start signal for the activation of an absorber are the major disadvantages of protective devices.
Besides the transmission of trigger signal to an energy absorber through cable communication reduces the reliability of
the operation of protective device due to a possible damage of electric wiring under blast or mechanical attack.
This paper presents the outcomes of the studies conducted to select accurate criteria for blast identification and to design
wireless system of activation of defensive device. The results of testing of blast detection methods (seismic, EMP,
optical, on overpressure) showed that the proposed method, which implies constant monitoring of overpressure in terms
of its reliability and response speed, best meets the requirements.
Proposed wireless system for explosions identification and activation of protective device consists of transmitter
and receiver modules. Transmitter module contains sensor and microprocessor equipped with blast identification
software. Receiver module produces activation signal for operation of absorber. Tests were performed in the
underground experimental base of Mining Institute. The time between the moment of receiving signal by the sensor and
activation of absorber - 640 microsecond; distance between transmitter and receiver in direct tunnel - at least 150m; in
tunnel with 900 bending - 50m.
This research is sponsored by NATO's Public Diplomacy Division in the framework of "Science for Peace".