CDC STACKS serves as an archival repository of CDC-published products including scientific findings, journal articles, guidelines, recommendations, or other public health information authored or co-authored by CDC or funded partners.
As a repository, CDC STACKS retains documents in their original published format to ensure public access to scientific information.
i
Procedures for determining support of excavations in highly yielding ground
-
1985
-
Series: Mining Publications
[PDF-1.30 MB]
Details:
-
Personal Author:
-
Corporate Authors:
-
Description:"This Bureau of Mines report describes the results of an investigation for developing and applying procedures for stabilizing excavations openings in highly yielding ground. The approach developed in this report involves nonlinear modeling of the progressive relaxation of the zones of rock mass around the excavations opening where coulomb criterion of failure is exceeded. Stresses are calculated by using a computer code
coulomb-failure condition is examined for both intact rock and joints (using strength parameters 0 and c). The rock mass in the failed zones is relaxed by reducing the young's modulus of the rock based on an empirical formulation that is a function of the shape of the opening and the extent of the failed zone. In addition, the material in the failed zone is assigned reduced strength parameters 0' and c'. The limiting (or convergent) relaxed zone is obtained through an iterative process by manually changing the rock modulus and the strength parameters between iterations. Support pressures are computed by applying forces normal to the excavation surface. The approach is applied to the analysis of stability and support requirements for an entry in a longwall coal mine." - NIOSHTIC-2
NIOSHTIC no. 10004812
-
Subjects:
-
Series:
-
Subseries:
-
Document Type:
-
Genre:
-
CIO:
-
Topic:
-
Location:
-
Pages in Document:19 numbered pages
-
NIOSHTIC Number:nn:10004812
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: