软岩隧道中基于快速预应力锚固支护的变形控制技术

以木寨岭公路隧道为依托,基于单一锚固形式的拉拔试验与交通隧道工程对锚固系统的要求,提出了适用于软岩大变形隧道且可实现及时支护理念的快速预应力锚固系统,并以其为核心载体,开展了支护技术应用试验研究.拉拔试验结果表明:受限于锚固成效、锚固力及锚固时间等因素,软岩隧道中涨壳式锚固和水泥药卷锚固均无法实现及时主动支护的功能;以...

Deformation Control Technology Based on Fast-prestressed Anchor Support in Soft Rock Tunnel

Relying on the Muzhailing highway tunnel,a fast-prestressed anchoring system,which is suitable for large deformation in soft rock tunnels and can realize the concept of timely support,is proposed based on the pullout test of single anchoring forms and requirements of the anchoring system in traffic tunnel engineering.Moreover,an experimental research on the application of support technology was carried out,with this anchoring system as the core carrier.The results indicate that both the expansion shell and cement roll anchoring cannot implement the function of timely active support in soft rock tunnels owing to factors such as anchoring effect,anchoring force,and anchoring time.Besides,a brand-new fast prestressed anchoring system of“timely(resin end anchor)+permanent(cement paste full-length grouting)”is proposed based on the cement paste anchoring with positive anchoring effect in the later period,and resin anchoring,which can be prestressed after rapid setting.Consequently,in the large deformation section of the relying project the comparative test study of the new support system was carried out with the fast-prestressed anchoring system as the core and strong passive support system.The results show that the fast-prestressed anchor support technology effectively restrains the displacement of surrounding rocks around the soft rock tunnel with the prestressed post-grouting resin anchor cable(birdcage type)system as the core.The arch roof settlement was reduced from 73-127 mm to 34-55 mm,the arch waist convergence was reduced from 295-740 mm to 157-430 mm,and the deformation stabilization time and deformation potential of the surrounding rocks were also significantly reduced,which validates the superiority of the deformation control technology based on fast prestressed anchoring support of large deformation tunnels in soft rock.