针对破碎软弱围岩隧道树脂锚杆施工难、可锚性差、缺少长期可靠的监测手段等问题，提出内置树脂预应力中空锚杆技术，并在西南地区某破碎软岩隧道开展试验研究，验证内置树脂预应力中空锚杆的可靠性；
将内置树脂预应力测力锚杆应用于隧道监测中，结合围岩位移和锚杆受力监测数据对锚杆支护方案进行优化，并通过数值模拟方法对优化方案进行验证。研究及现场实测结果表明： 1）采用内置树脂预应力中空锚杆实现了破碎软岩隧道锚杆机械化快速施工，塌孔段单根锚杆安装时间（含钻孔）为6~10 min，锚杆施工工效提升33%以上； 2）采用内置树脂预应力测力锚杆可实现对杆体力学状态的有效监测，波长值与锚杆拉拔力具有良好的线性关系； 3）围岩位移呈非对称性，围岩最大位移为305 mm，锚杆最大轴力为149 kN，均出现在拱顶右侧，需对原支护方案进行右侧补强优化； 4）经数值模拟验证，优化方案的锚杆最大轴力减小为126 kN，围岩最大位移减小为204 mm，围岩变形控制效果显著提升。
The application of resin
bolts to weak and broken surrounding rocks in tunnels faces numerous
challenges, such as difficult operations, poor anchorability, and a lack of
long-term reliable monitoring means. To
address these issues, a novel technical scheme of prestressed hollow anchor
bolts with built-in resin is applied to a weak and
broken rock tunnel in southwest China to validate its feasibility. Prestressed
hollow force-measuring anchor bolts are utilized for
tunnel monitoring, while a bolt supporting scheme is optimized based on the
monitoring data of surrounding rock deformation and bolt stress. Finally, the
proposed optimization scheme is verified by combining numerical simulation
results. Research results indicate the following: (1) The prestressed hollow
anchor bolts with built-in resin realize the mechanical
and rapid construction of broken and soft rock tunnels. The operation time
(including drilling) of these bolts in collapsed sections ranges at 6－10 min, and the construction efficiency of bolts is improved by
>33%. (2) The prestressed hollow force-measuring
anchor bolts with built-in resin can effectively
monitor their mechanical state, and the wavelength value shows a good linear
relationship with the anchor bolt pulling force. (3) Field measurements
indicate asymmetric tunnel deformation with a maximum displacement of 305 mm
and a peak axial force of 149 kN in anchor bolts, both of which are observed on
the right side of the tunnel crown. Therefore, the original bolt supporting
scheme needs to be reinforced and optimized on the right side. (4) Numerical
simulation shows that the maximum axial force and maximum deformation of the
surrounding rocks of the optimized solution are reduced to 204 mm and 126 kN,
respectively, indicating that the developed bolts can significantly enhance the
effectiveness of controlling surrounding rock deformation.
