The needle penetration index to estimate the performance of an axial type roadheader used in a coal mine

KAHRAMAN S. , Aloglu A. S. , Aydin B., Saygin E.

GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES, vol.5, no.1, pp.37-45, 2019 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 5 Issue: 1
  • Publication Date: 2019
  • Doi Number: 10.1007/s40948-018-0097-3
  • Page Numbers: pp.37-45


Roadheaders have been used widely in coal mining and tunneling for excavating low strength rocks. The performance prediction of a roadheader to be used is important for designing the projects and cost estimation. There are some performance prediction models for roadheaders in the literature. However, available models cover generally standard test methods which are difficult to carry out. This research investigates the predictability of performance of an axial type roadheader from the needle penetration index test which is a simple and practical test. The performance measurements of Dosco Mk-2B roadheaders were carried out during roadway excavations in Cayirhan Coal Mine. The performances of the machines were measured at nine different locations and the net cutting rate (NCR) values were calculated. The needle penetration tests were also carried out at least ten different points on the gallery faces during performance measurements and the needle penetration index (NPI) values were calculated. The NCR and NPI values were evaluated using regression analysis and a logarithmic relation with a very strong correlation coefficient was established between them. Increasing the NPI values decreases the NCR values. The derived relation was validated by the F test. It can be concluded that the NCR of axial type roadheaders can be easily estimated by using derived model for the similar rock types and conditions.