关键词: 地铁, 盾构, 锚索群, 人工挖孔竖井, 旋挖钻拔除, 地面加固

Abstract: When shield tunneling through anchor cable group, anchor cables should be removed. In this paper, a case study is conducted on four shield sections of west extension line of Shenzhen metro line 9, and six schemes are studied, including manual excavated shaft + anchor cable removing by cavity jack(scheme 1), manual excavated shaft + anchor cable removing by casting pipe(scheme 2), manual excavated shaft + anchor cable removing by rotary drill(scheme 3), mining excavation + shield advancing without force(scheme 4), anchor cable removing by rotary drill + ground reinforcement and shield pushing(scheme 5), and direct ground reinforcement + shield pushing(scheme 6). The shield tunneling construction experience and the anchor cable treatment technology are summarized. The results show the following: (1) The scheme 5 is optimal. (2) The schemes with manual excavated shaft are not feasible. (3) The scheme 4 has disadvantages such as long construction period, high cost, and difficult control of ground settlement. (4) The scheme 6 will increase the shield torque and cutter replacing times and reduce the tunnel speed. Accordingly, the scheme 5 is recommended.

Key words: metro, shield, anchor cable group, manual excavated shaft, anchor cable removing by rotary drill, ground reinforcement