岩石钻孔爆炸致裂研究

• 作 者: 郭晓钧 文鹤鸣
• 机 构: 南昌航空大学土木建筑学院,江西 南昌 330063;中国科学技术大学中国科学院材料力学行为和设计重点实验室,安徽 合肥 230027
• 出 处: 高压物理学报
• 发表日期: 2021年6期
• 关键词: granite?rocks constitutive?model borehole?blasting fracture

岩石在爆炸载荷作用下的动态断裂行为得到了土木、岩石、采矿、石油和天然气等工业领域的关注.为此,研究了岩石钻孔的爆炸致裂问题.首先简单描述了岩石的动态本构模型,确定了花岗岩动态本构模型的参数;然后利用该模型对岩石钻孔爆炸致裂进行了数值模拟;最后将数值模拟结果与花岗岩钻孔爆炸实验结果进行比较.结果表明:数值模拟预测的峰值压力和开裂形貌与文献报道的柱形花岗岩实验观察结果吻合较好,并且数值模拟得出的开裂形貌还与方形花岗岩实验观察结果较一致;开裂形貌主要由拉伸应力造成,而钻孔周围的小裂纹主要由压缩/剪切应力造成.“,”Dynamic fracture behavior of rocks under blasting loading are a major concern in civil engineering, mining, oil and gas industries. This study presented herein is on the borehole blasting-induced fractures in rocks. The paper consists of two parts: the first part gives a brief description of a constitutive model for rocks subjected to dynamic loading, which is mainly based on a recently developed model for concrete; the second part deals with numerical simulations of borehole blasting-induced fractures in rocks. The values of various parameters in the constitutive model for granite are first estimated and then employed in the numerical simulations. It is demonstrated that the numerical results in terms of peak pressures and crack patterns predicted from the present model are in good agreement with the experimental observations made both in cylindrical granite sample reported in the literature and in square granite specimens conducted in our own laboratory. Moreover, the analysis shows that the experimentally observed crack patterns are mainly caused by tensile stress, while the smaller cracks around borehole are created largely by compression/shear stress.