丽香铁路中义隧道预应力树脂锚杆设计施工关键技术

以丽香铁路中义隧道预应力树脂锚杆试验段为工程依托,对初支钢架大变形问题的系统锚杆效果进行研究。中义隧道地质为高地应力碎裂化玄武岩,开挖后初支钢架变形极为严重,关键线路工期滞后较多,且剩余地段围岩以Ⅴ级大变形为主,施工难度高、进度慢,需进一步研究变形控制及加快施工进度措施。根据煤矿行业相关工程经验,在以预应力树脂锚杆为主的主动支护体系方案基础上,及时开展施工工艺及工法现场试验工作。试验结果表明,预应力树脂锚杆可有效提供抗拔力并明显减小单日变形速率,避免初支侵限换拱,试验段累计变形得到有效控制,施工进度大幅提高,可为川藏、滇藏铁路等类似工程提供参考。

Key Design and Construction Technologies of Prestressed Resin Rockbolts in Zhongyi Tunnel of Lijiang-Shangrila Railway

Based on the test section of prestressed resin bolts in Zhongyi Tunnel of Lijiang-Shangrila Railway,the effect of system anchor bolts on large deformation of initial support steel frame is studied.Zhongyi Tunnel is geologically dominated by cataclastic basalt with high crustal stress.The deformation of initial support steel frame is extremely serious after excavation,and the construction of tracks lags behind.The surrounding rocks in the remaining sections are mainly deformed at Grade V,which makes the construction difficult and slow.Therefore,it is necessary to further study the measures for deformation control and acceleration of construction progress.According to relevant engineering experience of coal mine industry,the field test on construction technologies and methods are carried out in time based on the active support system scheme,focusing on the prestressed resin rock bolts.The test results show that the prestressed resin rock bolts can effectively provide uplift resistance and obviously reduce single-day deformation rate to avoid arch replacement due to the invasion of initial support,effectively control the cumulative deformation of the test section and greatly improve the construction progress,which may provide a reference for similar projects such as Sichuan-Tibet Railway and Yunnan-Tibet Railway.