深部岩芯饼化现象的应力机制探索
Exploration on Stress Mechanism of Deep Disked Core
作者：陆彤(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；高明忠(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；张茹(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；谢晶(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；谭强(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；鲁义强(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；何志强(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；汪文勇(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)；彭高友(四川大学 水利水电学院 水力学与山区河流开发保护国家重点实验室, 四川 成都 610065;四川大学 深地科学与工程教育部重点实验室, 四川 成都 610065)
Author：LU Tong(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；GAO Mingzhong(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；ZHANG Ru(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；XIE Jing(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；TAN Qiang(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；LU Yiqiang(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；HE Zhiqiang(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；WANG Wenyong(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)；PENG Gaoyou(State Key Lab. of Hydraulics and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China;Key Lab. of Deep Underground Sci. and Eng., for Minisity of Education, Sichuan Univ., Chengdu 610065, China)
收稿日期：2018-04-15 年卷（期）页码：2018,50(5):47-54
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：岩芯饼化;分维;破坏;应力机制;断面形貌
Key words：disked core;fractal dimension;damage;stress mechanism;fracture morphology
基金项目：国家重点研发计划资助项目（2016YFC0600701）；国家自然科学基金委面上资助项目（51674170）
中文摘要
岩芯饼化是深部工程区高地应力现象的典型表现之一，其饼化形貌特征一定程度上可以反映地应力大小与方向。依托世界埋深（2 400 m）最深的锦屏地下实验室，开展现场取样，详细记录不同孔号、孔向的饼化岩芯。基于3维蓝光LED非接触式扫描技术，获得了岩饼断面和侧面离散点精准3维数据，重构了岩饼断面和侧面的精细形貌，观察了岩饼的整体形态及端面错台的分布情况。同时，开展岩饼不同类型形态及不同方向剖面迹线的分形特征研究，并结合数值模型探讨了岩芯残根不同位置应力分布特征对岩芯饼化现象的影响。结果表明：岩饼断裂端面有4种表现形态，其中典型的形态为岩饼周边出现错台和岩饼呈现单侧变薄形态；岩饼端面剖面迹线最大分维值的方向与最大主应力分力方向一致。裂纹扩展可分为两种情况，从岩芯径向向内发展贯穿和从岩芯轴向开展，前者产生一侧偏薄、一侧偏厚的岩饼，后者会产生灯盏状破坏并在断面外围位置出现错台；前者反映了处于三向不等地应力条件下的岩芯裂缝将沿较大主应力方向扩展，后者探讨了钻杆钻进过程旋转和地应力共同作用下产生饼化现象的原因，反映了深部岩芯饼化现象的应力机制。研究结论可望为分辨饼化现象的成因及判识所处工程区地应力环境提供一些有益的参考。
英文摘要
Disked core is one of the typical performance of high geostress environment in deep engineering area, and its morphological features can reflect the stress intensity and direction to some extent. Relying on the world's deepest (2 400 m) Jinping underground laboratory, field work was carried out and the disked core of different holes and direction were recorded in detail. Based on blue light no-contact LED scanning technology, coordinate data of rupture surface and side in three dimensions were obtained accurately. Detailed morphology of rupture surface and side of core was reconstructed. The shape of disked core and distribution of small rock step were studied through scanning technology. Studies of different type of disked core and theirs fractal dimension on different directional profiles were done. Combined with the numerical model, the stress in different locations of core residual roots which may result in disked core was learned in depth. The results showed that rupture surface has four morphological types, among which small rock step appears at periphery of the core and the rock shows asymmetric thickness. The position of the maximum fractal dimension is the same as the direction of component part of maximum principal stress. Crack propagation can be divided into two situations. The direction of fissure is divided into radial and axial direction. The first mode of destruction produces the core with asymmetrical thickness. The second mode of destruction produces a lamp-like rupture surface and the phenomenon of small rock step appears on periphery of the section. The first mode showed that crack would propagate along the direction of larger geostress under three unequal geostress. The second explored the reason of disked core under combined effect of rotation of drill and geostress. These results reflected the stress mechanism of disked core which will be useful for distinguishing the cause of disked core and identifying the geostress environment.
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