الفهرس 
ARABIC SUMMARY
.Assumptions of Block TheoryOnly 14 pages are availabe for public view
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Abstract
The present study concerns with the application of block theory to compute some mining parameters at two different locations namely Maghara coal mine and Limestone quarry of Assiut cement company. At Maghara coal mine, Sinai, the parameters of support required to stabilize the dangereous blocks existing at the roof of the roadway were determined as well as the direction of the acting forces. At the limestone quarry, the block theory was applied to determine the safe limit of the angle of face slope in order to decrease the occurrence of dangerous potential key blocks.
Four joint sets were observed and measured at both Maghara coal mine and limestone quarry. A trace map for a section of the roof at Maghara mine was constructed using the scanline mapping technique to locate the position of the isolated blocks at the roof and to calculate their volumes to determine the sliding forces. The angle of internal friction and cohesive strength along the joint planes at Maghara mine were measured in the laboratory. Computer programs based on the vector analysis technique were developed to compute the removable block codes, the sliding direction, and sliding force for each block.
Tp stablize the key blocks at Maghara coal mine, it was suggested to use fully frouted cable bolt. A computer program was developed tp calculate the required cable lengths either when the direction of support was opposite to the dliding direction or when the direction of support was in the vertical direction. It was found that the required cable length in case of supporting against the sliding direction was shorter than that in the vertical direction. This means that the cost of support in the first cad\se (against sliding) is less than that of the second version, but the support installation in the vertical direction is more simpler and applicable.
A stereographic projection was also used in this work to determine the removable block codes and their sliding direction at Maghara mine. It was also used to calculate the maximum limit for the angle of dip of the free face at limestone quarry of Assiut cement company, which was found to be 77 .