广州地铁隧道施工中的盾构选型及盾构改进应用

APPICATION OF SHIELD SELECTION AND SHIELD IMPROVEMENT IN GUANGZHOU METRO SHIELD TUNNEL CONSTRUCTION

分析了盾构选型需考虑的因素,提出了盾构选型的流程,阐述了刀盘刀具对不同地层的切削机理。然后结合广州地铁二号线某区间隧道盾构施工实际情况,发现全断面滚刀设置不适合强度较低及粘性较强的的全风化地层,而适合强度较高的地层,其掘进速率分别为0.5 mm/d和2～4 mm/d;而全断面先行刀设置适合6#及8#岩层,不太适合9#微风化岩层,其掘进速率分别为8～10 mm/d和4～7 mm/d。

Factors that should be taken into account in shield selection were analyzed and the flow-chart of shield selection was established in this paper. The cutting mechanism of cutterhead was also described. Then,one of shield advancing cases of Guangzhou metro No.2 was illustrated to describe the shield selection and ground adaptability. The conclusions were that full face disc cutters are not suitable for completely weathered rock No.6 and No.8 but suitable for slightly weathered rock No.9 with advancing speed 0.5 mm/d and 2～4 mm/d respectively. On the contrary,the full face rip teeth cutters are suitable for rocks No.6 and No.8,and not for slightly weathered rock No.9,with the advancing speed 8～10 mm/d and 4～7 mm/d,respectively.