掘进机毕业设计---外文翻译.docx

英文原文 Abstract The factors affecting the performance of 90 kW-shielded roadheader is investigated in detail in a tunnel excavated for NuhCement Factory. The first part of the tunnel is horizontal and the second part is inclined with 9_ and excavated uphill. Tunnel passes through a formation of the Upper Cretaceous age with nodular marl, carbonated claystone, thin and thick laminated limestone. Water ingress changes from 0 to 11 l/min. In six different zones it is found that the rock compressive strength changed from 20 to 45 MPa, tensile strength from 1 to 4 MPa, specific energy from 11 to 16 MJ/m3, plastic limit from 15% to 29%, liquid limit from 27% to 43% and water absorption from 4% to 18% in volume. Detailed in situ observations show that in dry zones for the same rock strength the inclination of the tunnel and the strata help to increase the instantaneous cutting rate from 10 to 25 solid bank m3/cutting hour. The effect of water on cutting rate is dramatic. In the zones where the plastic limit and the amount of Al2O3 is low, instantaneous cutting rate increases from 34 to 50 solid bank m3/ cutting hour with increasing water content from 3.5 to 11 l/min. However, in the strata having high water absorption characteristic and high amount of Al2O3, cutting rate decreases considerably due to the sticky mud, causing problem to the cutterhead. Excavation, muck loading and support works are performed separately due to safety concerns in the wet and inclined sections which reduced the machine utilization time from 38% to 8%. The information gathered is believed to form a sound basis in contributing the performance prediction of roadheaders in difficult ground conditions. _ 2004 Elsevier Ltd. All rights reserved. Keywords: Tunnel excavation; Roadheader performance prediction; Core cutting test; Specific energy Introduction The application of roadheaders in difficult ground conditions, in recent years, has increased considerably in both civil and mining engineering fie