The Gaoloushan Tunnel in Longnan City,Gansu Province,China,frequently experiences rockburst disasters due to high in-situ stress.Managing rockburst in deep-buried tunnels remains a challenging issue.This paper employs...The Gaoloushan Tunnel in Longnan City,Gansu Province,China,frequently experiences rockburst disasters due to high in-situ stress.Managing rockburst in deep-buried tunnels remains a challenging issue.This paper employs RFPA(Rock Failure Process Analysis)software to establish a calculation model of constant resistance and large deformation(CRLD)anchorages and analyzes the effects of different support methods and pre-stress levels on rockburst.We simulate the process of tunnel rockburst disasters and find that ordinary anchor support incurs rockburst on the right arch waist and arch top,forming a V-shaped explosion pit.CRLD anchor support has several advantages in rockburst control,such as more uniform stress distribution in the surrounding rock,a uniform distribution of plastic zones,less noticeable damage to the tunnel,and effective control of the arch top displacement.The effectiveness of the CRLD anchor support under varying pre-stress conditions shows that a higher prestress results in a smaller plastic zone of the surrounding rock and arch top displacement and a lower number of acoustic emission signals,which better explains the excavation compensation effect.Moreover,adding long anchorages in the deep surrounding rock area can better control rockburst and reduce surrounding rock deformation.Based on these findings,we propose a comprehensive control system that combines long and short anchorages and provides the optimal scheme based on calculations.Therefore,by using high-prestress CRLD anchor support and the combination of long and short anchorages at critical positions,we can enhance the integrity of the surrounding rock,effectively absorb the energy released by the surrounding rock deformation,and reduce the incidence of rockburst disasters.展开更多
为提高软岩大变形隧道预应力锚索的施工质量与施工速度,推进软岩大变形隧道机械化施工进程,依托木寨岭公路隧道,基于预应力锚索机械化施工关键技术研发,以实现预应力锚索钻、装、锚、拉一体化施工为突破口,通过悬臂掘进机、多功能锚索...为提高软岩大变形隧道预应力锚索的施工质量与施工速度,推进软岩大变形隧道机械化施工进程,依托木寨岭公路隧道,基于预应力锚索机械化施工关键技术研发,以实现预应力锚索钻、装、锚、拉一体化施工为突破口,通过悬臂掘进机、多功能锚索台车等大型关键设备构建软岩大变形隧道全机械化施工方法,于武都右线方向开展试验段研究。得出主要结论:1)预应力锚索机械化施工关键技术的研发与集成,实现了软弱破碎围岩预应力锚索高效、稳定施工,锚索施工质量显著提升,锚索有效预应力提高近100 k N;2)软岩大变形隧道全机械化施工方法转变了传统依靠人力的施工模式,施工质量、施工速度得以大幅提升,初期支护施工人员减少1/5,单个初期支护施工循环时间缩短近2 h,洞周收敛减小值最大达48.6%。展开更多
基金funded by the National Natural Science Foundation of China(52174096,42277174)the Fundamental Research Funds for the Central Universities(2022YJSSB03)the Scientific and Technological Projects of Henan Province(232102320238)。
文摘The Gaoloushan Tunnel in Longnan City,Gansu Province,China,frequently experiences rockburst disasters due to high in-situ stress.Managing rockburst in deep-buried tunnels remains a challenging issue.This paper employs RFPA(Rock Failure Process Analysis)software to establish a calculation model of constant resistance and large deformation(CRLD)anchorages and analyzes the effects of different support methods and pre-stress levels on rockburst.We simulate the process of tunnel rockburst disasters and find that ordinary anchor support incurs rockburst on the right arch waist and arch top,forming a V-shaped explosion pit.CRLD anchor support has several advantages in rockburst control,such as more uniform stress distribution in the surrounding rock,a uniform distribution of plastic zones,less noticeable damage to the tunnel,and effective control of the arch top displacement.The effectiveness of the CRLD anchor support under varying pre-stress conditions shows that a higher prestress results in a smaller plastic zone of the surrounding rock and arch top displacement and a lower number of acoustic emission signals,which better explains the excavation compensation effect.Moreover,adding long anchorages in the deep surrounding rock area can better control rockburst and reduce surrounding rock deformation.Based on these findings,we propose a comprehensive control system that combines long and short anchorages and provides the optimal scheme based on calculations.Therefore,by using high-prestress CRLD anchor support and the combination of long and short anchorages at critical positions,we can enhance the integrity of the surrounding rock,effectively absorb the energy released by the surrounding rock deformation,and reduce the incidence of rockburst disasters.
基金Projects(51504247,52174092,51904290,52074259)supported by the National Natural Science Foundation of ChinaProject(BK20220157)supported by Natural Science Foundation of Jiangsu Province,China。
文摘为提高软岩大变形隧道预应力锚索的施工质量与施工速度,推进软岩大变形隧道机械化施工进程,依托木寨岭公路隧道,基于预应力锚索机械化施工关键技术研发,以实现预应力锚索钻、装、锚、拉一体化施工为突破口,通过悬臂掘进机、多功能锚索台车等大型关键设备构建软岩大变形隧道全机械化施工方法,于武都右线方向开展试验段研究。得出主要结论:1)预应力锚索机械化施工关键技术的研发与集成,实现了软弱破碎围岩预应力锚索高效、稳定施工,锚索施工质量显著提升,锚索有效预应力提高近100 k N;2)软岩大变形隧道全机械化施工方法转变了传统依靠人力的施工模式,施工质量、施工速度得以大幅提升,初期支护施工人员减少1/5,单个初期支护施工循环时间缩短近2 h,洞周收敛减小值最大达48.6%。
