软岩隧道中基于快速预应力锚固支护的变形控制技术  

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

作　　者：汪波[1] 王振宇[1] 郭新新[1] 朱安龙 王智佼 WANG Bo;WANG Zhen-yu;GUO Xin-xin;ZHU An-long;WANG Zhi-jiao(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;Huadong Engineering Corporation Limited,Hangzhou 311122,Zhejiang,China;Gansu Changda Highway Co.Ltd.,Lanzhou 730030,Gansu,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122 [3]甘肃长达路业有限责任公司,甘肃兰州730030

出　　处：《中国公路学报》2021年第3期171-182,共12页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(U2034205,51878571,51578456);四川省重点研发项目(2019YFG0001)。

摘　　要：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;以后期具备良好锚固效果的水泥浆锚固和能快速凝结后可施加预应力的树脂锚固为基础,提出了全新的“及时(树脂端锚)+永久(水泥浆全长注浆)”快速预应力锚固体系,并以其为基础,在依托工程大变形段开展了以快速预应力锚固系统为核心的新支护体系和强力被动支护体系的对比试验研究。对比试验结果表明:以预应力后注浆树脂(鸟笼型)锚索系统为核心的快速预应力锚固支护技术,有效抑制了软岩隧道洞周围岩位移,拱顶沉降由73~127 mm减至34~55 mm,拱腰收敛由295~740 mm减至157~430 mm,显著减少了围岩变形稳定时间与围岩变形潜势,验证了基于快速预应力锚固支护的变形控制技术在软岩大变形隧道中的优越性。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.

关 键 词：隧道工程 软岩隧道 现场试验 预应力锚固系统 及时主动支护 变形控制 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]