摘要
新建成兰铁路松潘隧道浅埋穿越松散破碎结构软岩,施工中出现了开挖面溜塌、支护体系持续变形不收敛、喷射混凝土开裂、钢架扭曲破坏等问题。本文在隧道所处的区域地质构造和开挖揭示的地质条件等基础上分析了上述问题的特征及其表现形态,对隧道的断面形式、超前加固措施、施工工法、支护参数等进行了优化设计;采取超前预注浆、微三台阶上部核心土法、系统锚管径向注浆及补强长锚杆等系列施工控制技术,提高了洞周岩体的物理力学性能,确保了开挖面的稳定和初期支护快速封闭成环,有效地控制支护体系的变形和破坏,保障了隧道施工安全和支护结构安全,确保隧道的顺利实施。
Songpan Tunnel from Chengdu to Lanzhou Railway is shallowly buried through soft rock "with loose and broken structure.During the construction,there are some problems such as slippage of the excavation surface,continuous deformation and non-convergence of the supporting system,cracking of sprayed concrete,and distortion of the steel frame have occurred.This paper analyzed the characteristics and manifestations of the above-mentioned problems on the basis of the regional geological structure of the tunnel and the geological conditions revealed by the excavation,and optimized the cross-section form of the tunnel,advanced reinforcement measures,construction methods,support parameters design;and adopted a series of construction control technologies such as advanced pre-grouting,micro-three-step upper core soil method,system anchor pipe radial grouting and reinforcing long anchor rods,which could improve the physical and mechanical properties of the surrounding rock mass and ensure the stability of the excavation surface and the initial support were quickly closed into a ring.Moreover,it could also effectively control the deformation and damage of the support system,guarantee the safety of tunnel construction and the support structure,and ensure the smooth implementation of the tunnel.
作者
张建慈
ZHANG Jianci(China Railway 25^(th)Bureau Group Co.Ltd.,Guangzhou Guangdong 510600,China)
出处
《铁道建筑技术》
2021年第3期61-66,共6页
Railway Construction Technology
基金
中铁二十五局集团有限公司科技研发计划项目(17-A7)。
关键词
松散破碎结构软岩
设计优化
超前预注浆
微三台阶上部核心土法
系统锚管
长锚杆
变形控制
soft rock with loose and broken structure
design optimization
advanced pre-grouting
micro-three-step upper core soil method
system anchor pipe
long anchor rod
deformation control
作者简介
张建慈(1969-),男,广东梅州人,高级工程师,主要从事工程施工技术研发及管理工作,E-mail:848564988@qq.com。
