堡镇隧道高地应力顺层偏压软岩大变形段的快速施工技术

Rapid Construction Technology for Baozhen Tunnel in Heavily Deforming Soft Rock Stratum with High Ground Stress and Bedded Strata Asymmetrical Load

堡镇隧道的主要工程地质特点是在高地应力、顺层偏压、软岩地质条件下隧道发生大变形。在对国内外高地应力软岩隧道施工技术研究现状基础上,分别对顺层偏压地层和高地应力顺层偏压地层隧道施工力学行为分析,制定了"超前支护、初支加强、合理变形、先放后抗、先柔后刚、刚柔并济、及时封闭、底部加强、改善结构、地质预报"的快速施工原则和总体方案。通过对开挖方法、通风方式、机械设备配套技术及管理技术等方面的综合攻关,实现了同类工程安全无事故条件下的快速施工。

The main geological characteristics of Baozhen Tunnel are high ground stress, bedded strata asymmetrical load and large deformation of tunnel in soft rock. Based on the study of the tunnel construction technology in soft rock with high ground stress both in China and foreign countries, the author makes analysis on mechanical behavior of tunnels in asymmetrical-loaded stratum and asymmetrical-loaded and highly stressed strata respectively. Then, the author presents the composite construction principle of advance support, enhanced primary support, reasonable deformation, proper stress releasing before stress resisting, flexible support installed before rigid support, timely closing the support structure, strengthening tunnel invert, optimizing tunnel structure and geological predication. The excavation method, ventilation method, equipments matching technology and management technology adopted has ensured the safe and rapid construction of the tunnel.