基于核磁共振技术的岩体爆破损伤试验研究

EXPERIMENTAL STUDY OF ROCK DAMAGE BY BLASTING BASED ON NUCLEAR MAGNETIC RESONANCE TECHNIQUE

评价岩体爆破损伤程度及其范围对工程爆破参数设计和岩体结构支护具有重要指导意义。在综合分析当前岩体爆破损伤研究方法的基础上,引进核磁共振检测技术,从研究爆破作用导致岩石损伤的本质着手,以岩石孔隙度、横向弛豫时间T2谱等参数为判据,以及核磁共振成像技术这一直观方式定量确定岩体爆破损伤范围。同时,结合超声波测试和岩石力学强度测定等技术手段对核磁共振结果进行比较和论证,并研究核磁共振特征与岩体强度之间的相关性,得出核磁共振孔隙度与单轴抗压强度之间的呈指数分布,并建立单轴抗压强度的预测模型。研究结果表明,核磁共振技术具有较高的实用性和准确性,为研究爆破岩体损伤开辟一种新的技术手段。

Evaluation of blasting damage degree and range of rock mass is important in the blasting parameter design and structure support. Based on the comprehensive analysis of the current methods in studying rock mass damage caused by blasting, the nuclear magnetic resonance（NMR） detection technique is introduced. Beginning with studying the essential reason of blasting damage, the porosity and T2 spectrum distribution are regarded as the criterion, as well as the NMR images, the range of rock mass blasting damage is quantificationally analyzed. Combined with the ultrasonic testing and rock mechanics strength measurement techniques, the NMR results are discussed and compared. In addition, the relationship between the NMR characteristics and rock mass strength has been discussed, which conform to exponential distribution. And a prediction mathematical model of uniaxial compressive strength, is established based on the NMR results. The results show that the practicability and accuracy of NMR are better, which opens up a new technical method for studying the blasting damage of rock mass.