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Title: Method of investigations, estimation, and classification of roofs in mines in the United States of America for the selection of suitable mechanized support for longwalls. Report No. 1: January 1, 1977-March 31, 1977

Technical Report ·
OSTI ID:6332821

The basic objective of present research project is to test and classify roof rocks in US coal mines. It will enable: rational selection of longwall supports - mean load density and type of support - for various roof conditions; evaluation of maximum distance between support and coal rib side for different classes of mine roofs; and forecasts of conditions for roof control - regular caving initiation. As can be seen from the report, the CMI penetrometer system should be redesigned for maximum pressure of about 2000 kg/cm/sup 2/ to allow for testing of higher strength rocks found in US mine roofs. It is necessary to design a new type of penetrometric head and a pump. For in-situ testing of rocks in the full range of strength, a brief program of four-weeks investigation in selected US mines is presented. The proposed plan of the SOA report on roof testing and support selection is presented. After USDI approval of the suggestions CMI will continue the research project according to the schedule of Phase I, namely: four-weeks visit of CMI experts to the United States for preliminary in-situ estimations of rock strength; redesigning of the penetrometer system; and SOA report preparation.

Research Organization:
Glowny Inst. Gornictwa, Katowice (Poland)
OSTI ID:
6332821
Report Number(s):
DOE/TIC-11477; ON: DE81028714
Country of Publication:
United States
Language:
English