深部圆形隧洞板裂屈曲岩爆的模拟试验研究

发布时间：2018-05-23 15:12

本文选题：岩石力学 + 隧洞　；参考：《岩石力学与工程学报》2017年07期

【摘要】：为了深入认识深部圆形隧洞中板裂屈曲岩爆的发生机制,采用大尺寸真三轴岩石试验系统对含预制孔洞红砂岩立方体(100 mm×100 mm×100 mm)试样进行模拟试验研究。首先根据地应力随深度分布规律,在水平向垂直隧洞轴向方向设定最小主应力,竖直向垂直隧洞轴向方向设定最大主应力,在3个方向分别加载到初始应力状态。然后保持另外2个方向应力不变,在竖直向垂直隧洞轴向方向进行加载直至隧洞洞壁围岩发生破坏,并且在保证试样整体不发生破坏条件下,逐级加载至洞壁发生岩爆。利用安装的微型摄像机对试验过程中洞壁围岩破坏全过程进行实时监测和记录,结合三维加载和洞壁受力情况,再现了深埋硬岩圆形隧洞板裂屈曲岩爆全过程。研究结果表明:岩爆过程可划分为平静期、细颗粒弹射和剥落期、板裂屈曲破坏和强烈破坏四个时期。岩爆可滞后应力发生,具有时间效应,并且受加载率影响明显。岩爆破坏深度达到更高静应力水平下的稳定状态,形成的V 型槽具有应力不敏感期;通过合理优化隧洞断面几何参数,可发挥结构强度尺寸效应,对岩爆发生起一定抑制作用。
[Abstract]:In order to deeply understand the mechanism of buckling rock burst in deep circular tunnel, a large size true triaxial rock test system was used to simulate the specimen containing 100 mm 脳 100 mm red sandstone with prefabricated holes. Firstly, according to the distribution of ground stress with depth, the minimum principal stress is set in the axial direction of the horizontal vertical tunnel, the maximum principal stress is set in the axial direction of the vertical tunnel, and the initial stress is loaded into the initial stress state in three directions respectively. Then the stress of the other two directions is kept unchanged, loading in the vertical tunnel axial direction until the surrounding rock of the tunnel wall is destroyed, and under the condition that the whole specimen is not destroyed, the rockburst occurs step by step to the wall of the tunnel. The whole process of wall rock failure is monitored and recorded by using the installed micro camera. Combined with 3D loading and wall loading, the whole process of deep buried hard rock circular tunnel slab crack buckling and rockburst is reappeared. The results show that the rock burst process can be divided into four periods: calming period, fine grain ejection and spalling stage, buckling failure of plate crack and strong failure. Rock burst can cause delayed stress, which has time effect and is obviously affected by loading rate. The rock burst failure depth reaches the stable state under the Gao Jing stress level, and the V-shaped groove has a stress insensitive period, and the structural strength size effect can be brought into play by optimizing the geometric parameters of the tunnel section reasonably. It can inhibit the occurrence of rock burst to some extent.
【作者单位】：中南大学资源与安全工程学院;中南大学高等研究中心工程材料力学研究所;
【基金】：国家自然科学基金资助项目(41472269) 国家重点研发计划项目(2016YFC0600706) 中南大学中央高校基本科研业务费专项资金项目(2017zzts167)~~
【分类号】：TV554

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