Mining Publication / Nejlevnější knihy
Mining Publication

Kód: 08270352

Mining Publication

Autor Department of Health and Human Services, National Institute for Occupational Safe

This U.S. Bureau of Mines report examines the roof and floor contact pressure provided by the interaction of a shield with the surrounding strata. Controlled forces were applied to an 800-ton two-leg shield in the Bureau's mine ro ... celý popis

375


Skladem u dodavatele
Odesíláme za 9-15 dnů
Přidat mezi přání

Mohlo by se vám také líbit

Dárkový poukaz: Radost zaručena

Objednat dárkový poukazVíce informací

Více informací o knize Mining Publication

Nákupem získáte 38 bodů

Anotace knihy

This U.S. Bureau of Mines report examines the roof and floor contact pressure provided by the interaction of a shield with the surrounding strata. Controlled forces were applied to an 800-ton two-leg shield in the Bureau's mine roof simulator; the distribution of forces acting on the canopy and base of the shield were measured with 24 hydraulic pressure cells. Several influential factors that affect the load distribution were investigated: (1) the magnitude of loading (leg pressure); (2) the profile of the canopy, principally the upward-sloping tip; (3) the base-lifting device; (4) horizontal load acting on the shield; and (5) compliancy of the immediate roof and floor. It was concluded that the shield does not develop full canopy or base contact without deformation of the strata. Maximum contact pressures are developed at the rear of the canopy and on the toes of the base. Less than 10 pct of the available shield capacity is developed at the canopy tip despite the design intention to ensure tip contact. Horizontal loading reduced the toe pressure acting on the base by as much as 75 pct. The base-lifting device exaggerated the inherently high toe loading, increasing the contact pressure by more than 200 pct.

Parametry knihy

Zařazení knihy Knihy v angličtině Society & social sciences Politics & government

375



Osobní odběr Praha, Brno a 46566 dalších

Copyright ©2008-26 nejlevnejsi-knihy.cz Všechna práva vyhrazenaSoukromíCookies


Můj účet: Přihlásit se
Všechny knihy světa na jednom místě. Navíc za skvělé ceny.

Nákupní košík ( prázdný )

Vyzvednutí v Balikovně a PPL
boxech
zdarma nad 1 499 Kč.

Nacházíte se: