浅埋隧道预应力锚固体承载效应模型实验研究  

Model test study on bearing effect prestressing anchors in shallow buried tunnels

作　　者：王彤彤 刘文龙 曹立雪 秦哲 张润昌 WANG Tongtong;LIU Wenlong;CAO Lixue;QIN Zhe;ZHANG Runchang(College of Civil Engineering and Architecture,Shandong University of Science and Technology,Qingdao Shandong 266590,China;Key Laboratory of Geological Safety of Coastal Urban Underground Space,Ministry of Natural Resources,Qingdao Shandong 266101,China;Qingdao Geology and Geotechnical Engineering Co.,Ltd.,Qingdao Shandong 266101,China)

机构地区：[1]山东科技大学土木工程与建筑学院,山东青岛266590 [2]自然资源部滨海城市地下空间地质安全重点实验室,山东青岛266101 [3]青岛地矿岩土工程有限公司,山东青岛266101

出　　处：《矿业科学学报》2024年第3期370-380,共11页Journal of Mining Science and Technology

基　　金：自然资源部滨海城市地下空间地质安全重点实验室基金(BHKF2022Y03)。

摘　　要：预应力锚杆主动支护技术在隧道工程中的应用逐渐普及,对于浅埋大跨岩质隧道,其支护特性及作用机制尚未明确。为探究预应力锚杆支护体系下围岩的承载特性,以青岛地铁6号线某暗挖车站为工程背景,基于相似原理配制地层及支护结构模型实验材料,通过液压加载试验,探究了预应力锚杆及普通锚杆支护下锚固体的承载特性。结果表明:①预应力锚杆与围岩的相互作用形成了具有承载能力的锚固体,能够有效承担大部分上覆荷载。预应力锚杆的应用使得隧道失稳破坏的预警荷载值提高了42.8%,同时极限荷载值也提高了41.2%。②在上覆加载过程中,预应力锚杆经历了紧密锚固持荷阶段和脱锚卸荷阶段,衬砌经历了应变累积、应变突增和应变释放3个阶段。③较普通锚杆,主动支护下预应力锚杆与岩体间的受力协同性好,无轴力突变现象,锚杆的支护性能得到充分的利用,有效抑制了裂隙的发育,提高了隧道的整体稳定性。The use of prestressing anchor active support technology in tunnel engineering is becoming morecommon.However,the support characteristics and mechanism of action have not been fully understood for shallow,large-span rocky tunnels.In order to investigate the bearing characteristics of the surrounding rock under the prestressed anchor support system,a concealed excavation station of Qingdao Metro Line 6 was used as the engineering background,and based on the similarity principle of formulating experimental materials for stratum and support structure modelling,the bearing characteristics of the anchors under the prestressed anchor and ordinary anchor support were investigated by hydraulic loading tests.The results indicate that:①The interaction between prestressed anchors and the surrounding rock creates a load-bearing anchor solid that can effectively support most of the overlying loads.The application of prestressed anchors during the overburden loading process increased the warning load value of tunnel instability damage by 42.8%and the ultimate load value by 41.2%.②The overburden loading process involved the prestressing anchors going through the tight anchorage load holding stage and the de-anchorage unloading stage.Simultaneously,the lining underwent the strain accumulation stage,strain surge stage,and strain release stage during the overlay loading process.③The prestressed anchor under active support has better force synergy with the rock body than an ordinary anchor,without the axial force mutation phenomenon.This allows the support performance of the anchor to be fully utilized.Additionally,the prestressed active support effectively inhibits the development of fissures and significantly improves the overall stability of the tunnel.

关 键 词：浅埋大跨隧道 预应力锚杆 主动支护 锚固体 模型实验 

分 类 号：TU91[建筑科学—建筑理论] TD354[矿业工程—矿井建设]