艾里逊变速箱油:隧道类英语比较厉害的高手帮翻译下。

2.1. Collapse zone (Ch: 36+617–36+610)
Collapse took place in an oversaturated fault gouge zone lying behind the face and dipping steeply into
the tunnel. The occurrence and the large extent of the collapse zone resulted from the failure to locate the
fault zone and by delaying installation of necessary support elements during the previous round of excavation cycles (between Ch: 36 + 625 and 36 + 617). Absence of rock bolting in the initial support system, the highly stressed nature of the rock mass and softening or loosening of the clayey material in the
fault gouge contributed to the occurrence of collapse.Initially, water started flowing through the left sidewall
of the top heading as dictated by the natural hydraulic gradient, and gradually extending the eroded zone towards the floor. Eventually, the tunnel was filled with 92 m3 of collapse debris (Fig. 6). The flow rate recorded in this segment reached 3 l/s.
To prevent the spread of the collapse, this pile of debris supporting the remaining part of the excavation face was quickly dammed and stabilized by external materials. Following this, a total of 28 m3 of shotcrete was applied to the collapsed area to create a 20-cmthick rigid layer. Subsequently, additional stabilization measures and support installation between Ch:36 + 617 and 36 + 610 were carried out in the following sequence: (a) a total of 33 forepoling pipes (length:6 m, /: 1.5 in.) were driven along the roof section of the collapse face to form a rigid canopy; (b) wire mesh (/: 131–131) was fitted on to the initial shotcrete layer with the help of T-shaped drive-in bolts; (c) an additional layer of 16-cm-thick shotcrete (22 m3) were formed; and (d) a total of 12 rock bolts (length: 8 m, /:28 mm, ultimate load: 25 t) and 27 NPI steel ribs were installed.
Following the prevention of collapse zone enlargement, 44 m3 (BS 20) of concrete and 80 m3 of shotcrete were used to restore the tunnel section in the collapse area. Then consolidation grouting using
various cement mixture ratios (cement/water ratio:1/1, 7/5 and 7/5+ % 25 sand mixture and % 2–4 bentonite) was carried out under 3 bar pressure to reduce the density of the concrete fill and recover the strength of the weakened zone around this section. A total of 44.2 t of cement was used during this process. A total of 12 drainage pipes (length: 6 m,/: 3 in.) were installed on both sidewalls to decrease water pressure behind the grouted zone. In addition to all these, a pattern (1.5–1.25 m) of rock bolts (length: 6 m, /: 28 mm) was applied between Ch:36 + 625 and 36 + 617 to limit deformation due to stress re-distribution during the advance of the tunnel face. Thus, the propagation of collapse was stopped and safety conditions required to resume the excavation were established (Fig. 6).