浅埋软弱围岩隧道掌子面GFRP筋锚杆预加固技术研究

Due to the higher standers of technical and passenger dedicated line and highway, a large number of shallow buried tunnels have been popularly used to fulfill the high speed railway and highway construction. For most of the construction of shallow buried tunnels which were in the soft rock condition, the stability of tunnel face is the key to ensure the safety of this type of tunnel construction. With the advantage of high tensile strength, machinable and more, glass fiber reinforced polymer (GFRP) can reinforce the core soil of tunnel face, in the meantime it can ensure the rapid excavation and safe construction of the tunnel without prejudice to the excavation tunneling. As the key of the New Italy Tunnel Method (NITM) of tunnel face bolt reinforcement technology in China has just started. As a new technology, NITM in the construction of tunnels in China has not been applied, and the corresponding reinforcement parameters, design method and construction technology need to be systematically studied. . According to the current research and the plastic limit analysis upper bound theorem, the upper bound solution of ultimate supporting force for the shallow buried soft rock tunnel face has been derived, and been applied to evaluated the safety of tunnel face. The glass fiber reinforced (GFRP)’s reasonable diameter, anchor mortar strength and anchorage length has been determined through indoor performance test. Based on the above research results, through the numerical method analyzing the GFRP reinforcement length, root number and range of the shallow buried weak surrounding rock tunnel face, the reasonable GFRP reinforcement parameters has been obtained. The GFRP bolt pre-reinforcement technology of shallow buried tunnel in soft rock has ultimately formed.

由于客运专线及高速公路技术标准的提高，出现了大量浅埋隧道；在浅埋软弱围岩地质条件下，掌子面稳定是保证隧道安全施工的关键。玻璃纤维筋（GFRP）具有抗拉强度高、可切削等优点，加固掌子面核心土同时，不影响隧道掘进速度，能保证隧道施工快速安全进行。而作为新意法核心的掌子面锚杆加固技术在我国刚起步，其相应的加固参数、设计方法和施工工艺等均有待系统研究。.根据国内外研究现状，本项目基于塑性极限分析上限定理，推导得到浅埋软岩隧道掌子面极限支护力的上限解，并对掌子面安全性进行评价；通过室内玻璃纤维筋（GFRP）锚固性能试验，确定出合理筋材直径、锚固砂浆强度以及锚固长度；基于以上研究成果，结合数值方法对浅埋软弱围岩隧道掌子面GFRP筋加固长度、根数及范围等对掌子面的加固效果进行模拟分析，得到合理的GFRP筋锚杆加固参数。最终形成浅埋软弱围岩隧道掌子面GFRP筋锚杆预加固技术。

由于客运专线及高速公路技术标准的提高，出现了大量浅埋隧道；在浅埋软弱围岩地质条件下，掌子面稳定是保证隧道安全施工的关键。玻璃纤维筋（GFRP）具有抗拉强度高、可切削等优点，加固掌子面核心土同时，不影响隧道掘进速度，能保证隧道施工快速安全进行。而作为新意法核心的掌子面锚杆加固技术在我国刚起步，其相应的加固参数、设计方法和施工工艺等均有待系统研究。.根据国内外研究现状，本项目基于塑性极限分析上限定理，推导得到浅埋软岩隧道掌子面极限支护力的上限解，并对掌子面安全性进行评价；通过室内玻璃纤维筋（GFRP）锚固性能试验，确定出合理筋材直径、锚固砂浆强度以及锚固长度；基于以上研究成果，结合数值方法对浅埋软弱围岩隧道掌子面GFRP筋加固长度、根数及范围等对掌子面的加固效果进行模拟分析，得到合理的GFRP筋锚杆加固参数。最终形成浅埋软弱围岩隧道掌子面GFRP筋锚杆预加固技术。