Powered Supports Incompatibility in a Longwall Panel and Determination of Support Capacity

摘要

A very peculiar failure of powered-roof supports has been observed in the Longwall Panel-5 in the coalseami of a mine in the Ramagundam area of India. It is due to very high geological disturbances and incompetence of the powered-roof supports. Both the strata and the powered-roof supports behave erratically in this mine. The front legs of a number of powered supports used to become solid at a time whereas negative pressure (less than percentero) observed at their rear legs. The details about the investigation, examination and analysis of the behaviour of the strata and the powered-roof supports are highlighted in this article. Based on the study of various longwall faces in different coalfields in India, the author develops a very simple but realistic mathematical model to determine the optimum capacity of the powered supports. This concept along with other associated developed formulae by the author determines the type and optimum capacity requirement of the powered supports to be used in the said coal seam of the nearby mines. The calculated value of the capacity of the existing type chock shield support is 5511. This type of design is considered to be inferior one since all the legs are not oriented against the stresses coming from the roof strata.. The optimum capacity of the suggested chock shield support per unit to be used in the seam 1 of the said and nearby mines of the Ramagundam area is 6171,