深埋隧道长短锚杆锚固围岩破坏模型试验  

Experimental of Failure Process of Long and Short Rockbolts for a Week Deep Tunnel

作　　者：王凤云 潘锐 蔡毅 聂利青 蔡永祥 唐民军 WANG Feng-yun;PAN Rui;CAI Yi;NIE Li-qing;CAI Yong-xiang;TANG Min-jun(Anhui Provincial Key Laboratory of Intelligent Underground Detection,Anhui Jianzhu University,Hefei 230601,China;School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China)

机构地区：[1]安徽建筑大学安徽省智能地下探测重点实验室,合肥230601 [2]安徽建筑大学土木工程学院,合肥230601

出　　处：《科学技术与工程》2025年第6期2480-2489,共10页Science Technology and Engineering

基　　金：国家自然科学基金(42402273,52374073);安徽省高校自然重点基金(KJ2020A0455);安徽建筑大学科研项目(2019QDZ13,2019QDZ52)。

摘　　要：为研究长短锚杆对深埋隧道软弱围岩锚固效果的影响,通过室内相似模型试验,开展隧道开挖后围岩的加载破坏试验,对比分析3种工况下(无锚、短锚和长锚)围岩破坏、变形和应力变化规律。结果表明:加载开挖隧道后的围岩,其破坏顺序表现为边墙和拱腰依次剪切破坏,最后拱顶塌陷;锚固后的围岩拱顶由于锚杆的锚固作用形成了“加强梁”的作用,使拱顶承受的最大沉降及其破坏荷载显著增加;锚杆的长度需要穿过拱顶塑性松动区,若锚杆长度不足以锚固整个塑性松动区,被锚固的围岩与上部未被锚固的围岩之间存在“分层”现象。根据锚固围岩强度均一化理论得到,短锚杆主要是增加浅层洞壁处围岩的有效支护力,从而提高了洞壁处围岩强度,长锚杆主要是调节深部围岩弹性区应力状态,长短锚杆组合使用可有效调节围岩应力状态。To study the effect of anchor length on anchorage effect of weak rock masses in a deep tunnel,the indoor similar model tests were carried out on failure test of rock masses during the excavation opening.The variation characteristic on the failure,displacements and stress of the rock mass after excavation were analyzed comparatively under three conditions(without anchors,with short anchors and long anchors).In the loading test,the failure process of rock mass around the opening shows that the failure process of surrounding rock occurs first at the side wall,then the arch waist and the arch collapse.The surrounding rock in the arch roof after reinforcing rock bolts forms the effect of strengthening beam because of the reinforcement of rock bolts,which leads to the significant increase in the maximum settlement and failure load of the arch roof.The length of rock bolts need to pass through the plastic loosening zone of the arch roof.If the length of anchor rod is not enough to anchor the whole plastic loosening zone,there will be stratification between the anchored surrounding rock and the unanchored surrounding rock.Based on the theory of homogenization strength of rock mass,the short bolt mainly increases the effective support force of surrounding rock at shallow tunnel wall,thus improving the strength of surrounding rock,and the long bolt(cable)can regulate the stress in the elastic zone of deep surrounding rock.Therefore,the combination of the long bolt(cable)effectively regulates the stress state of surrounding rock.

关 键 词：隧道围岩 模型试验 锚杆长度 变形破坏 塑性区半径 

分 类 号：TU458[建筑科学—岩土工程]