摘要
在乌兹别克斯坦卡姆奇克隧道岩脉型岩爆特点总结的基础上,分析了岩脉型岩爆的形成机制,建立了该隧道危害最大的边墙岩脉型岩爆的力学模型,提出了相应的岩爆控制技术。研究表明:岩脉型岩爆的特点及危害与岩脉在隧道中的出露位置、厚度等密切相关,这类岩爆的形成机制与单一岩性并不一致;卡姆奇克隧道拱部岩脉型岩爆是由于隧道开挖后拱顶切向应力最大造成的;边墙出露岩脉型岩爆是由于隧道开挖卸荷和边墙竖向应力集中造成的,力学模型可简化为被卸荷裂隙切割的岩脉薄板在竖向应力集中后的压溃失稳;边墙内藏岩脉型岩爆是由于边墙出露的花岗岩受到其后岩脉的水平挤压以及隧道开挖后边墙竖向应力集中造成的,力学模型可简化为边墙临空花岗岩岩板(柱)在竖向压力和岩脉水平挤压应力共同作用下的压弯折断;岩脉对边墙花岗岩岩板(柱)的水平挤压是促使边墙内藏岩脉型岩爆发生的重要因素,它主要来源于两方面:一是岩脉侵入产生的"楔体挤压",二是岩脉与花岗岩的水平差异变形受到花岗岩的抑制导致的水平挤压。隧道开挖后,在边墙及时施作预应力锚杆是防止边墙岩脉型岩爆的有效措施。
Based on the summarized characteristics of vein rockburst in the Uzbekistan Kamchik tunnel,the paper analyzed the formation mechanism of vein rockburst,established the mechanical model of the most dangerous vein rockburst in side wall of Kamchik tunnel and proposed corresponding controlling technology for rockburst.The research shows that the characteristics and hazards of vein rockburst are closely related to the location and thickness of the vein.The formation mechanism of this rockburst type is inconsistent with rockburst under single lithology.Vein rockburst occurred in vault of Kamchik tunnel results from the maximum tangential stress on vault after tunnel excavation.Exposed vein rockburst of side wall is caused by excavation unloading and vertical stress concentration in side wall,and the mechanical model can be simplified as the crushing instability when the thin vein plate is cut by unloading crack after the vertical stress concentration.Hidden vein rockburst behind side wall is mainly due to the horizontal extrusion of the vein behind granite and the vertical stress concentration of side wall after tunnel excavation.The mechanical model can be simplified as the bending and breaking of the free rock plate(pillar)of the side wall under the combined action of vertical stress and horizontal compression of the vein.The horizontal extrusion of vein towards granite rock plate(pillar)of the side wall is a major contributor to hidden vein rockburst behind side wall.It mainly comes from the"Wedge extrusion"caused by intrusion of vein and the horizontal extrusion from the horizontal differential deformation between vein and granite that are suppressed by granite.Hence,timely application of anchors on the side wall is an efficient way to prevent vein rockburst of side wall.
作者
刘成禹
罗洪林
李红军
张向向
LIU Cheng-yu;LUO Hong-lin;LI Hong-jun;ZHANG Xiang-xiang(College of Environment and Resources,Fuzhou University,Fuzhou,Fujian 350116,China;Research Center of Geological Engineering,Fuzhou University,Fuzhou,Fujian 350116,China;China Railway Tunnel Group Co.,Ltd.,Guangzhou,Guangdong 511458,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2021年第5期1413-1423,1433,共12页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.41272300)
中铁隧道集团科技创新重大项目(隧研合:2014-23)。
关键词
隧道
岩脉
岩爆
挤压
力学机制
防治
tunnel
vein
rockburst
extrusion
mechanical mechanism
prevention
