Open AccessSTUDY ON STABILITY CONTROL OF COAL MINE TUNNEL EXCAVATED IN WEAK ROCK MASS IN INDONESIA
Author(s) -
Phanthoudeth Pongpanya,
Takashi Sasaoka,
Hideki Shimada,
Vongsavanh Soysouvanh
Publication year - 2021
Publication title -
international journal of engineering applied science and technology
Language(s) - English
Resource type - Journals
ISSN - 2455-2143
DOI - 10.33564/ijeast.2021.v06i04.018
Subject(s) - arch , roof , shotcrete , coal mining , geotechnical engineering , mining engineering , rock mass classification , engineering , electronic stability control , excavation , geology , coal , structural engineering , waste management , automotive engineering
This paper focuses on the stability analysis andsupport design of the coal mine tunnel excavated in weakrock mass in an Indonesian underground coal minethrough numerical simulations using the FLAC3Dsoftware. The PT Gerbang Daya Mandiri (GDM) coalmine situated in Indonesia was selected as a mine site inthis study. According to the results of a series of numericalsimulations, the stability of the mine tunnel decreases byincreasing the depth and stress ratio. Ground controlproblems, for example falling roof, sidewall collapse, andfloor heave are expected unless an appropriate supportsystem is anticipated. Three support systems, includingfriction rockbolt, steel arch, and shotcrete are discussed asmethods to stabilize the roof and sidewalls of the minetunnel. From the simulated results, the steel arch isconsidered to be the most effective support method whencompared with other support systems. The steel archwhich is installed with closer space and larger crosssection delivers a better stability control to the roof andsidewalls of the mine tunnel. Although the stability of theroof and sidewalls of the mine tunnel can be maintainedeffectively by the steel arch support, the occurrence offloor heave is expected when the mining depth is increased.To control the floor stability of the mine tunnel, threetechniques by applying cablebolt, invert-arch floor, andgrooving method are therefore investigated and discussed.Based on simulated results, the heaving of the floor is wellcontrolled after the cablebolt, invert-arch floor, andgrooving methods are applied. Nevertheless, it is foundthat controlling the floor heave by cablebolt support couldbe the most suitable method comparing with other supportsystems in terms of the installation process, providing flatand safe working conditions of the floor, and economy.Additionally, the cablebolt with closer row space andlonger length works more effectively to control the heavingproblem of the floor.Keyword