Roadheader performance during development of a coal drive

摘要

Drilling and blasting is the most widely used excavation method in mining and tunnelling especially in hard rock conditions. But in recent years, the application of mechanical excavators in hard rock, especially in fractured geological formations has increased considerably. Mechanical excavation is very attractive for many project because of their techno-economic advantages including improved safety, ease from automation, finished and undamaged excavation dimension, almost nil ground vibration, etc. Under mechanical excavation roadheaders can be a good option. It is a versatile excavation machines favoured in mining operation due to a high degree of mobility, flexible cutting profile, selective mining, providing immediate access to the face and the capability to cut medium strengths rocks. It is also seen performing in high strength rock but only in case of moderately jointed roclcs. Performance analysis ofroadheader in soft rock drivages is an important task. This can be determined by studying various performance tests or models and carrying out actual underground cutting. With this respect, a data-base was established from detailed field data including the measured instantaneous cutting rates (ICR) and geo-mechanical parameters (uniaxial compressive strength) of the coal measure rocks for each cutting condition in the tunnels. In this paper the study was conducted at two different coal mines to analyse the performance of roadheader vis-a-vis performance predicted by one model. It was found that the roadheaders are working below the predicted performance in development drive of coal mine.