نوع فایل: power point قابل ویرایش 27 اسلاید قسمتی از اسلایدها: Performance of roadheader The roadheader production rate and bit costs are controlled by several parameters including: Rock parameters, such as rock compressive and tensile strength, percent of hard and abrasive mineral content ( i.e. quartz), rock fabric and matrix type, and elastic behavior of rock material etc. Ground condition, such as degree of fracture (RQD), joint condition, ground water, fault zones, rock mass classification and support requirements etc. Machine specification, including machine weight, cutterhead power, sumping, arcing, lifting, and lowering forces, cutterhead type(axial or transverse), bits type, size, and other characteristics, number and allocation of bits on the cutter head etc. Effect of rock strength Samples taken from zone 5 have compressive strength of 210 kg/cm2 and specific energy of 11.2 MJ/m3, and samples taken from ...
