Iron Miners
It is currently Sat Nov 18, 2017 8:17 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
 Post subject: Odds of Subsidence while in a mine...
PostPosted: Thu Oct 05, 2006 2:04 pm 
Offline

Joined: Thu Sep 21, 2006 1:05 am
Posts: 20
Does weather or age of mine affect this? Are mines that are hewn out of rock less likely to collapse?


Top
 Profile  
 
 Post subject:
PostPosted: Thu Oct 05, 2006 2:28 pm 
Offline
User avatar

Joined: Fri Jul 15, 2005 2:34 pm
Posts: 6906
Location: Within 60 Miles of the Northern Anthracite Field
Frank has some good points but also to point out that most subsidences happen in workings that are close to the surface, this is caused by, running water, freezing and thawing ground, small sizemic events, rain water seeping through to name a few. we have seen a few places where subsidences into workings were only 8-10 feet below the surface. in steeply pitching coal mines subsidences usually happen where the coal face deteriorates and it is close to the surface causing a crop fall, or chute opening to the surface. many mines actually did this for ventilation purposes. in flat pitch mines they are usually caused by simply mining too close to the surface. in archbald there was a subsidence directly below the rr tracks, and there is a manway entrace near. so we went in the manway then saw where they filled the subsidence with concrete. that was pretty cool. check this out....

http://www.undergroundminers.com/subsidenceindex.html

_________________
Come over to the Dark Side....... We have Cookies!


Top
 Profile  
 
 Post subject:
PostPosted: Sun Oct 08, 2006 6:52 am 
Offline
Site Admin

Joined: Mon Jun 20, 2005 11:33 pm
Posts: 3088
Location: Above the Sterling Hill Mine
Did you ever get pictures of the concrete fill from under the ground in Gravity? It would be interesting to see actually...

Miner Greg


Top
 Profile  
 
 Post subject:
PostPosted: Sun Oct 08, 2006 7:22 am 
Offline
User avatar

Joined: Mon May 08, 2006 2:16 pm
Posts: 1501
Location: Central Ohio
In our coal mines the roof fails for several reasons. Most are deep enough 100-300' ft below. We just have really bad roofs. Most of the newer mines have roof bolts or I-beams or concrete if we are really lucky. We have pics that still show collapses dispite the bolting & I-beams. We do not have hard rock most of the time it is sandstone, shale or what ever soft rock is above the coal seams. This makes it really difficult but our mines are extreamly high production because the seams are flat and most of the time consistant seam thicknesses 4'-20'. This is a good thing because this will allow us to use long wall miners ( A cutting machine that cuts up to 1250 ft wide). This machine processes the coal at an unbelievable rate but the roof collapses behind it as it moves. Now that is very interesting to actually hear & watch the roof fall behind you. The downside is that you can not explore these mines only the main haulage routes. Our mines are the mines that keep the lights on! Just because of the high production.

_________________
Pioneering the next INDUSTRIAL REVOLUTION (Preservation ! ). . . Saving equipment (1) mine site at a time.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Oct 08, 2006 8:18 pm 
Offline
User avatar

Joined: Fri Jul 15, 2005 2:34 pm
Posts: 6906
Location: Within 60 Miles of the Northern Anthracite Field
also to point out that the bituminous coal mines collapse more because the coal is softer and pillars crush out alot easier, in room and pillar method of course.

chris

_________________
Come over to the Dark Side....... We have Cookies!


Top
 Profile  
 
 Post subject:
PostPosted: Sun Oct 08, 2006 8:23 pm 
Offline
User avatar

Joined: Mon May 08, 2006 2:16 pm
Posts: 1501
Location: Central Ohio
Actually your not supposed to put the pillars on the coal surface but it does happen. The miners put the pillars on the rock face but that is still usually soft, remember the dual track haulage tunnel where the roof let go in a couple of places.

_________________
Pioneering the next INDUSTRIAL REVOLUTION (Preservation ! ). . . Saving equipment (1) mine site at a time.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group