Author(s)

S. Torno, E. Alvarez, B. Arias & J. Toraño

Abstract

Sudden methane outbursts which often cause serious accidents with numerous fatalities can be produced in underground coalbed roadways and when driving tunnels for highways or railways passing through carboniferous materials. Most of the factors which take part in the generation of sudden outbursts are related to methane conditions into the coalbed and specifically to gas pressure and coal permeability. When excavating roadways or tunnels crossing coalbeds, it is convenient to have easy to use equipment which allows us to know at any moment the measured pressure and its variation in factors such as roadway and tunnel driving velocity, geological faults which lead to fractured formations and natural or induced overstresses. The designed gas-pressure-measurement-tube set goes into an 8 m deep and 45 mm in diameter borehole drilled in front of the working face. The gaspressure- measurement-tube set is connected to a flexible rod with a manometer at the end of it. The obtained measurements are used both in the empirical formulae and in Computational Fluid Mechanics; this allows us to predict the probability of the occurrence of sudden outbursts. Keywords: gas pressure, methane, outburst, gas-pressure-measurement tube, underground mine.

Keywords

gas pressure, methane, outburst, gas-pressure-measurement tube, underground mine