摘要
为评估大断面软弱围岩隧道突泥涌水风险,结合广东省江门至罗定高速公路王北凹隧道实例,建立了基于可拓法的隧道突泥涌水风险评估模型。通过计算分析表明,隧道左、右线LK100+354~LK99+988.5与RK100+385~RK99+978段突泥涌水风险等级极高,同时隧道开挖结果也进一步验证了风险评估结果。经研究分析,采取了"引、堵、排"结合的隧道突泥涌水控制原则,加强隧道超前地质预报,初期支护采用V级围岩的支护参数(I20b工字钢纵向间距75 cm;φ8@20 cm×20 cm双层钢筋网;26 cm厚C20喷射混凝土)。此外,超前支护采用双层注浆小导管,并采取帷幕注浆对掌子面进行封闭加固。实践表明,采取的风险控制措施合理可靠,能有效地控制隧道突泥涌水灾害。
For evaluating risk of water or mud inrush of large cross-section tunnel in weak rock,and being combined with Wangbeiao Tunnel of Jiangmen-Luoding Expressway in Guangdong Province,the risk assessment model of water or mud inrush during tunnel construction has been established in accordance with extension theory. Through the calcula-tion and analysis,the results have shown that the risk of water or mud inrush is extremely high in section of LK100 ＋ 354 ~ LK99＋988.5 and RK100385 ~ RK99 ＋978. At the same time,tunnel excavation also has verified the results of risk assessment. Through comprehensive analysis,the principle of “ diversion,plugging,drainage＂ should be taken in controlling water or mud inrush. The geological forecast has been also strengthened during tunneling. The initial support has adopted those for rock grade V,namely I-shaped steel of I20b with 75 cm longitudinal spacing, double-layer steel meshes （8 mm@ 25 cm grid）, and C20 sprayed concrete with thickness of 26 cm, etc. In addition, double - layer grouting pipes have been used as advanced support,and soil reinforcing measures have also been taken on tunnel face. The risk control measures have been proved to be reasonable and reliable, which could effectively control water or mud inrush during tunnel excavation.
出处
《广东公路交通》
2017年第4期88-94,共7页
Guangdong Highway Communications
关键词
软弱围岩
隧道
突泥涌水
风险评估
控制措施
weak rock
tunnel
water or mud inrush
risk assessment
control measures
