摘要
为保证软弱围岩条件下扁平型超大断面隧道的安全开挖,以某富水凝灰岩层内隧道为例,结合隧道的结构与地质特性,提出一种改良的双侧壁导坑法的安全施工方法——双侧壁导坑结合微台阶法。将传统工法与改良工法相结合,并应用于实际施工过程。利用数值仿真技术,建立模型并进行分析,将得到的衬砌结构和围岩的力学响应特征与现场监控量测数据进行了验证比对。研究结果表明:与原施工方案相比,新采用双侧壁导坑结合微台阶法及其辅助施工措施能有效减少围岩扰动和二次衬砌的不利影响,未开挖的微台阶围岩及其辅助施工措施能对初期支护提供支撑阻力,降低了初支沉降风险,保证了开挖掌子面和初支的安全稳定。
In order to achieve the safe excavation of large flat-shaped section tunnel under the weak surrounding rock condition,an improved double-side drift safety construction method—double side drift with micro-bench method was proposed based on the structure and geological characteristics of the tunnel which was excavated in a water-rich tuff stratum.Through using numerical simulation technology,the actual construction process of the traditional and the improved methods was modeled and analyzed,and the mechanical response characteristics of the lining structure and surrounding rock were compared with the on-site monitoring measurement.The results show that the adverse effects on the surrounding rock disturbance and the secondary lining was effectively reduced by the double side drift with micro-bench method and auxiliary construction measures.In addition,the risk of initial support settlement was reduced because of the unexcavated micro-bench and corresponding auxiliary measures can provide support resistance for primary support.The safety and stability of the heading face and primary support was ensured using the improved method.
作者
黄迪辉
蓝柳海
张江山
HUANG Di-hui;LAN Liu-hai;ZHANG Jiang-shan(Changsha Investigation Institute of Uranium Engineering,Changsha 410000,China;No.2 Engineering Co.,Ltd.,of CCCC First Highway Engineering Co.,Ltd.,Suzhou 215000,China;School of Resources and Safety Engineering,Central South University,Changsha 410083,China)
出处
《交通科学与工程》
2019年第4期71-77,共7页
Journal of Transport Science and Engineering
关键词
扁平型隧道
超大断面
双侧壁结合微台阶法
flat-shaped tunnel
super-large section
double side drift with micro-bench method
