1552 The predicted and measured values are also correlated and presented in Figure 2. From the correlation it is evident that the developed models for road header exhibits a similar trend of performance in application of continuous miner in coal, but the actual values are significantly different. Therefore, it may be inferred that the rock-tool interaction trend is established in this by these models but the production is different due to soft geo-mining characteristics of coal (Uday, 2015). 4. NEW CUTTABILITY INDEX FOR CONTINUOUS MINER Considering the requirement of a specific index for continuous miner, CMCI is proposed. CMCI incorporates the influence of compressive strength, tensile strength, RQD, power and weight of CM (Dey and Uday 2021). The new CMCI model is - sXsZ = (L×Q) (0.5 ×ásJ×—SJ)×ç V 1 P 00 O é!/Z Where, CMCI = Continuous miner cuttability index, P = Power of machine (kW), W = weight of the machine ( tonne ) UCS = Uniaxial compressive strength ( MPa ) BTS = Brazilian tensile strength ( MPa ), RQD = Rock quality designation Statistical regression analysis is carried on the measured and MICR and developed CMCI with a index of determination (R2) value of 0.85. It is found that the CMCI can be used for arriving at the Predicted Instantaneous Cutting Rate equation (PICR) using the model given below-: LZsV = 18.74×sXsZ <.Y} 5. CONCLUSIONS Continuous miner (CM) is the state-of-the-art technology for coal cutting in underground mines. The production from CM may be predicted using cutability indices. In this research, production from CATCM345 is monitored at different underground coal faces. Some of the geotechnical properties are also measured. As CM is closely resembled to road header, the production from the machine is predicted using the existing cuttability indices. The MICR and the predicted Instantaneous cutting rates using BICR (Bilgin, 1988), GICR (Gehring, 1989) and CICR (Copur et al, 1997) are showing acceptable trend. However, these models are not in close agreement with the actual production of CM. This may be attribute by the weak strength properties of the coal, which is different from the hard rock excavation system. A new continuous miner cuttability index (CMCI) is developed. The parameters considered in CMCI are – UCS, BTS, RQD, CM power and CM weight. Nineteen sets of data are used to develop CMCI. A predictive model for instantaneous cutting rates (PICR) is developed using CMCI model and is correlated with the MICR. PICR is found in close agreement with the actual production rates. REFERENCES Bilgin N., Seyrek T. and Shahria K., (1988), Golden Horn Clean up Contributes Valuable Data, Tunnels and Tunneling, June, pp. 41- 44.
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