市政技术2025，Vol.43Issue(12)：65-73,81,10.DOI:10.19922/j.1009-7767.2025.12.065
软弱地层隧道平行导坑横通道进正洞施工技术研究
Research on the Construction Technology of the Parallel Pilot Pit Transverse Passage Entering the Main Tunnel in Weak Stratum Tunnels
班改革1
作者信息
- 1. 中铁十八局集团有限公司,天津 300000
- 折叠
摘要
Abstract
To address the critical issues of poor stability,difficulty in deformation control,and complex disturbances at the tunnel intersections of weak strata,the mechanical behavior of strata at the juncture of parallel pilot and main tunnels in high-speed railways were analyzed in this research.Factors affecting the plastic zone were analyzed by supporting theory.Combined with numerical simulation,the stratum control effects under different lateral advance lengths of the upper bench in the main tunnel were compared and the stratum reinforcement measures and support schemes were proposed.Key findings include:1)The extent of the plastic zone is positively correlated with single excavation area so that the use of short excavation steps in large-section tunnels is advocated to minimize lateral step distance.2)Cross-excavation markedly enlarges the plastic zone.Under V-grade surrounding rock,a 4 m trans-verse spacing effectively controls both the plastic zone and lining deformation.The arch's plastic zone depth is re-duced by 49.51％than single-excavation.And,the step length was further reduced which offered limited improve-ment of control effects.3)The palm face arch crown is a primary stress concentration area which needs anchor rod support,while the controlling the upper arch's plastic zone requires enhanced vertical support.4)The practical en-gineering solution is implemented by a 4～6 sections horizontal excavation on the upper steps.Combined 4-meter system anchor rods with upper arch steel frames in the main tunnel to form a tunneling and support system based on plastic zone control.关键词
高速铁路隧道/平行导坑/结构变形控制/地层塑性区/锚杆长度设计Key words
high-speed railway tunnel/parallel pilot pit/structural deformation control/stratum plastic zone/de-sign of anchor bolt length分类
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班改革..软弱地层隧道平行导坑横通道进正洞施工技术研究[J].市政技术,2025,43(12):65-73,81,10.
