摘要
为了研究结构面对深埋隧道硬质围岩岩爆特征的影响,对有无结构面的两种圆形隧道立方体砂岩试样进行了真三轴条件下岩爆模型试验,试验中采用声发射系统监测了岩爆演化过程。研究发现:结构面对岩爆发生的位置、洞壁破坏模式、岩爆剧烈程度具有较大的影响。无结构面试样两侧破坏位置对称,围岩边壁有较多岩片剥落,形成较浅的V型凹槽;有结构面试样洞壁两侧破坏位置不对称,远离结构面一侧有大量岩片剥落,形成较深的V型凹槽,结构面附近则产生多条裂纹,导致隧道与结构面之间岩体有向隧道空间垮塌的趋势;有结构面试样声发射事件活跃度更高,单个撞击的平均能量约为无结构面试样的2.2倍;根据累计撞击数的演化规律,将岩爆分为3个阶段,阶段Ⅰ为微裂纹闭合及线弹性阶段,阶段Ⅱ为裂纹萌生及稳定扩展阶段,阶段Ⅲ为微裂纹非稳定发育直至发生岩爆阶段。有结构面的试样进入阶段Ⅱ的时间比不含结构面试样早;两种试样在破坏过程中产生的裂纹均为张拉剪切混合裂纹,其中有结构面试样的剪切裂纹占比更大。结构面的存在改变了试样初始损伤的位置,声发射定位与隧道破裂形态基本一致。
This study examines the evolution of rockburst in hard surrounding rock of a deep-buried tunnel affected by structural planes.True triaxial rockburst model tests were conducted on cubic sandstone specimens with a circular tunnel,with and without structural surfaces.An acoustic emission system was used in the experiment to monitor the evolution process of rockburst.Results show that the structural planes significantly affect the position and intensity of rockburst,as well as the failure mode of cavern wall.The damaged zone is symmetrical on both sides of specimens without a structural plane.Several rock flakes form a shallow V-shaped notch in the sidewall of the circular tunnel.The failure position on both sides of specimen with a structural plane is asymmetrical.On the side distant from the structural plane,a large number of rock flakes peel off,forming a deep V-shaped notch.Near the structural plane,multiple cracks form,causing the rock mass between the tunnel and the structural face to tend to collapse into the tunnel space.The acoustic emission(AE)events in specimen with structural plane are much more active,with the average energy of a single impact being approximately 2.2 times that of the specimen without a structural pane.According to the evolution of cumulative impact count,the loading process before rockburst can be divided into three stages,including crack closure and linear elastic deformation,crack initiation and stable propagation,and crack unstable development.The crack initiation and stable propagation is earlier in specimen with a structural plane than that in specimen without a structural plane.All cracks generated during the failure process are tension-shear mixed pattern in both tested specimens.The proportion of shear cracks is larger in specimen with a structural plane compared to that without.The presence of structural plane changes the position of initial damage in specimen.The AE location in the experiment generally correspond to the failure pattern of circular tunnel.
作者
韩世迎
王航龙
彭俊
朱君星
王林飞
潘堃
HAN Shi-ying;WANG Hang-long;PENG Jun;ZHU Jun-xing;WANG Lin-fei;PAN Kun(Faculty of Land and Resources Engineering,Kunming University of Science and Technology,Kunming,Yunnan 650093,China;State Key Laboratory of Safety and Health for Metal Mines,Sinosteel Maanshan General Institute of Mining Research Co.,Ltd.,Maanshan,Anhui 243000,China)
出处
《岩土力学》
北大核心
2025年第6期1765-1776,共12页
Rock and Soil Mechanics
基金
国家重点研发计划(No.2023YFC2907201)
国家重点研发计划青年科学家项目(No.2022YFC2905700)
国家自然科学基金重点项目(No.52130403)
安徽省自然科学基金(No.2208085ME120)
安徽省重点研发计划(No.2022m07020001)。
关键词
结构型岩爆
隧道
V型凹槽
真三轴加载
声发射
structure-type rockburst
circular tunnel
V-shaped notch
true triaxial loading
acoustic emission(AE)
