掘进机毕业设计---外文翻译

掘进机毕业设计---外文翻译内容摘要：

ed as is the production rate for the actual () cutting time of the machine (ton or solid bank m3/cutting hour). Machine utilization time (MUT) is the excavation time as a percentage (%) of the total working time, excluding all the stoppages. Advance rate (AR) is the linear advance rate of the tunnel or drift excavation (m/shift, m/ day, m/week and m/month) and is a function of ICR, MUT and crosssection area of the excavated face. Water ingress and geological discontinuities in the tunnel face were also recorded. The recorded instantaneous cutting rate, water ingress, RQD values of the face and machine utilization time values are tabulated for different tunnel zones in Table 3. Machine utilization, percentages of stoppages and other planned jobs such as ring montage, site surveying, etc. are presented in Fig. 3. 7 .The effect of strata inclination One of the most accepted methods for determining the roadheader cutting rate in horizontal and widely jointed rock formation is to use laboratory cutting specific energy obtained from instrumented core cutting test (McFeatSmith and Fowell, 1979). As seen from Table 2, the samples taken from nodular marl, zone 1, have the specific energy value of 11 MJ/m3, which corresponds to an instantaneous cutting rate of 8 solid bank m3/cutting hour for noninclined strata and medium weight roadheaders in the McFeatSmith and Fowell’s model. However, it is observed in the site that the inclination of the strata is in favor of the cutting action and the muck is easily ing out from the excavated area. The instantaneous cutting rate in this area (zone 1) is recorded to be 10 solid bank m3/cutting hour. . The effect of tunnel inclination In zone 5, having the same pressive strength and specific energy values as in zone 1, the instantaneous cutting rate is more than double being 25 solid bank m3/ cutting hour. The inclination of the tunnel, hence, the gravity forces help the muck being loaded easily and ing quickly on the cut face preventing the muck recirculation within the cutting head and the face. . The effect of rock strength and specific energy values Samples taken from zone 5 have pressive strength of 210 kg/cm2 and specific energy of MJ/m3, and samples taken from zone 6 have pressive strength values of 450 kg/cm2 and specific energy values of MJ/m3. This is reflected in instantaneous cutting rate values being 25 solid bank m3/cutting hour in zone 5 and 20 solid bank m3/cutting hour in zone 6. . The effect of water The effect of water on the instantaneous cutting rate is dramatic. The water ingress in zone 2 is 11 l/min and zone 5 is dry, the samples taken from these two zones have the same pressive strength. However, the instantaneous cutting rate in the wet zone (50 solid bank m3/cutting hour) is twice (double) more than in the dry zone (25 solid bank m3/cutting hour). This might be due to the fact that the water reduces the strength of the strata and helps the muck ing easily from the tunnel face. . The effect of wet sticky zone Water ingress in zone 3 is the same as in zone 2, being 11 l/min. The samples taken from zone 3 have the same strength as zone 2. However, it is observed in the site that the muck in zone 3 is sticky (muddy) and sticks the cutting head, hence, decreases the instantaneous cutting rate from 50 to 20 solid bank m3/cutting hour. The samples taken from zone 3 have Al2O3 content of %, water absorption of %, plastic limit of 29% and liquid limit of 43%. XRD analysis show that the clay in zone 3 consists of nontronite and kaolinite. The pictures of the original (new, unused) cutting head (on top) and the mud on the cutting head after utilizing in the wet sticky zone (at the bottom) are seen in Fig. 4. Zones 2 and 4 have similar geotechnical properties, although the water ingress in zone 4 is l/min being onethird of the water ingress in zone 2. This is reflected dramatically on the instantaneous cutting rate value, which is 31 solid bank m3/cutting hour in zone 4 and 50 solid bank m3/cutting hour in zone 2. . The effect of lamination It is considered that lamination affects the instantaneous cutting rate. Thin laminated limestone (zone 2) has a thickness varying between 2 and cm. The instantaneous cutting rate in zone 2 reaches at an average of 50 solid bank m3/cutting hour, which is the maximum rate among all of the zones, as seen in Table 3. On the other hand, the chemical position of the excavated formations affects the instantaneous cutting rate, as well. Although the thin laminated limestone (zone 2) and thin laminated silisified limestone (zone 5) have similar thicknesses, the instantaneous cutting rate is lower in zone 5, being 25 solid bank m3/cutting hour, which might be due to silisification, as well as being dry. The thickness of thick laminated clayey limestone (zone 6) is greater than 60 cm. Therefore, it can be concluded that, based on previous researches (Bilgin et al., 1988, 1990, 1996, 1997), lamination does not increase the instantaneous cutting rate in zone 6. It is a known fact that discontinuity spacing smaller than around 10 cm increases the instantaneous cutting rate. Joint type discontinuities affect similarly the all of the zones in the region. Since the RQD values are similar in all of the zones, Table 3, the effect of joints on the roadheader performance cannot be deduced. . The factors affecting machin。