Skip directly to site content Skip directly to search


Español  Other Languages


Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People
 Search
		×
			NIOSH
			NIOSH
				All CDC
				Submit
			For a full list of topics:A-Z Index
			Advanced Search
		Advanced Search


The National Institute for Occupational Safety and Health (NIOSH)


Section Navigation
			
			CDC Home








Agriculture, NIOSH Research Projects						Print
																Related Pages
										April 1997
DHHS (NIOSH) Publication Number 97-124
97-124 Cover
A massive pillar collapse occurs when undersized pillars fail and rapidly shed their load to adjacent pillars, which in turn fail. The consequences of these chain-reaction failures can be catastrophic. One effect of a massive pillar collapse can be a powerful, destructive, and potentially hazardous airblast. Thirteen recent massive pillar collapses have been documented in West Virginia, Ohio, Utah, and Colorado. Data collected at the failure sites indicate that all of the massive collapses occurred where the pillar width-to-height (w/h) ratio was 3.0 or less and where the Analysis of Retreat Mining Pillar Stability Factor was less than 1.5. The unique structural characteristics of these pillar systems apparently result in sudden, massive pillar failures, rather than the more common slow “squeezes. The field data, combined with theoretical analysis, provide the basis for two partial-extraction design approaches to control massive pillar collapses. These are the *containment* approach and the *prevention* approach; practical examples are provided of each.
Agriculture, NIOSH Research Projects
							
					
							Last Reviewed:  April 21, 2017						Source: 	National Institute for Occupational Safety and Health
					Facebook
        Twitter
        LinkedIn
        Syndicate homeNIOSH Publications & Products
NIOSH-Issued Publications
Search NIOSHTIC-2 Research Database
Docket
Documents for Public Review
Peer Review Agenda
Databases
eNews
Federal Register Noticesplus icon
FRN Archive 2007-2010
FRN Archive 2005-2006
FRN Archive 2001-2004
FRN Archive 1996-2000
Press Releases and Updatesplus icon
Press Release Archives 2010-2013
Press Release Archives 2006-2009
Press Release Archives 2001-2005
Press Release Archives 1998-2000
Press Release Archives 1992-1997
Regulations
Regulatory Agenda
Science Blog
Software
Video Follow NIOSH Facebook
Pinterest
Twitter
YouTube
 NIOSH Homepage NIOSH A-Z
Workplace Safety & Health Topics
Publications and Products
Programs
Contact NIOSH


About CDC
					Contact Us
					800-232-4636
 Facebook Twitter Instagram LinkedIn Youtube Pinterest Snapchat
 CONTACT CDC
				Contact Us
							Call 800-232-4636
							Email Us
			ABOUT CDC
				About CDC
							Jobs
							Funding
			POLICIES
				Accessibility
							External Links
							Privacy
							Policies
							No Fear Act
							FOIA
							OIG
							Nondiscrimination
							Vulnerability Disclosure Policy
			CONNECT WITH US
				Facebook
								Twitter
								Instagram
								LinkedIn
							Youtube
								Pinterest
								Snapchat
								Email
			LANGUAGES
				Español
							繁體中文
							Tiếng Việt
							한국어
							Tagalog
							Русский
							العربية
							Kreyòl Ayisyen
							Français
							Polski
							Português
							Italiano
							Deutsch
							日本語
							فارسی
							English


U.S. Department of Health & Human Services
			Accessibility
			External Links
			Privacy
			Policies
			No Fear Act
			FOIA
			Nondiscrimination
			OIG
			Vulnerability Disclosure Policy
			USA.gov


Exit Notification / Disclaimer Policy Close
 Links with this icon  indicate that you are leaving the CDC website. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
				Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
				You will be subject to the destination website's privacy policy when you follow the link.
				CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. Website Disclaimers
 Cancel Continue