TY - JOUR

T1 - Theoretical Investigations on the Influence of Artificially Altered Rock Mass Properties on Mechanical Excavation

AU - Hartlieb, Philipp

AU - Bock, Stefan

PY - 2017/11/9

Y1 - 2017/11/9

N2 - This study presents a theoretical analysis of the influence of the rock mass rating on the cutting performance of roadheaders. Existing performance prediction models are assessed for their suitability for forecasting the influence of pre-damaging the rock mass with alternative methods like lasers or microwaves, prior to the mechanical excavation process. Finally, the RMCR model was chosen because it is the only reported model incorporating a range of rock mass properties into its calculations. The results show that even very tough rocks could be mechanically excavated if the occurrence, orientation and condition of joints are favourable for the cutting process. The calculated improvements in the cutting rate (m3/h) are up to 350% for the most favourable cases. In case of microwave irradiation of hard rocks with an UCS of 200 MPa, a reasonable improvement in the performance by 120% can be achieved with as little as an extra 0.7 kWh/m3 (= 1% more energy) compared to cutting only.

AB - This study presents a theoretical analysis of the influence of the rock mass rating on the cutting performance of roadheaders. Existing performance prediction models are assessed for their suitability for forecasting the influence of pre-damaging the rock mass with alternative methods like lasers or microwaves, prior to the mechanical excavation process. Finally, the RMCR model was chosen because it is the only reported model incorporating a range of rock mass properties into its calculations. The results show that even very tough rocks could be mechanically excavated if the occurrence, orientation and condition of joints are favourable for the cutting process. The calculated improvements in the cutting rate (m3/h) are up to 350% for the most favourable cases. In case of microwave irradiation of hard rocks with an UCS of 200 MPa, a reasonable improvement in the performance by 120% can be achieved with as little as an extra 0.7 kWh/m3 (= 1% more energy) compared to cutting only.

KW - Mechanical excavation

KW - performance prediction

KW - alternative rock cutting

KW - microwave irradiation

KW - laser cutting

KW - high-pressure water jet

U2 - 10.1007/s00603-017-1355-3

DO - 10.1007/s00603-017-1355-3

M3 - Article

VL - 51.2018

SP - 801

EP - 809

JO - Rock mechanics and rock engineering

JF - Rock mechanics and rock engineering

SN - 0723-2632

IS - March

ER -