1. State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou　 221116,China;
2. School of Civil Engineering,Chongqing University,Chongqing　 400045,China

岩石材料由于其天然形成过程的复杂性,内部赋存了大量的微裂隙、孔洞等缺陷。为研究岩石孔洞之间的相互作用机制及孔洞对岩石力学行为的影响,分别对不同次孔洞直径和不同孔洞几何布置的双圆形孔洞砂岩试样进行单轴压缩试验,以获得其强度、变形及破裂演化规律。试验结果表明,随着孔心连线与水平方向倾角α的增大,试样峰值强度和弹性模量均呈先减小后增大的趋势,在α为30°和90°时分别达到最小值和最大值;随着次孔洞直径d的增大,峰值强度和弹性模量均呈逐渐减小的趋势。双圆形孔洞砂岩的破坏形式受到倾角α和次孔洞直径d的影响,主要表现在起裂形式、主孔洞破裂形式及主次孔贯通模式三个方面。随着倾角α的增大,主次圆孔间的相互作用先逐渐增强后又有所衰减,而随着次孔洞直径d的增大,主次圆孔间的相互作用逐渐增强,这在双圆孔的贯通模式上得到了很好的印证。

A large number of micro cracks,holes and other defects appear in the rock material because of the complex- ity of its natural formation process. In order to study the interaction mechanism between the cavities and the effect of the cavities on the mechanical behavior of rock,the uniaxial compression tests were conducted on the sandstone sam- ples with the different geometric arrangements of holes and the diameters of the side holes to obtain their strength,de- formation and fracture evolution laws. The result demonstrates that both the peak strength and elastic modulus of the samples show the trend of first decrease then increase with the increase of the angle. The minimum and maximum val- ues reach at α = 30° and α = 90°;the peak strength and elastic modulus show a gradually decrease with the increase of the diameter of the side hole. The damage form of the sandstone containing double circular cavities is affected by the angle and the side hole diameter,mainly in the three aspects of crack initiation forms of the samples,the fracturing be- havior of the central hole and the coalescence mode of the double circular cavities. The interaction between the central hole and the side hole gradually increases and then gradually decreases with the increase of the angle,the increase of the diameter of the side hole can also enhance the interaction between the central hole and the side hole,and this has been confirmed in the void coalescence.

国家重点基础研究发展计划(973)资助项目(2013CB036003)；国家自然科学基金资助项目(51374198)；中国博士后基金资助项目(2016M590518)；

Han Guansheng,Jing Hongwen,Su Haijian,et al. Experimental study on compressive strength and fracture characteristics of sandstone con- taining double circular cavities[J]. Journal of China Coal Society,2017,42(4):871-878.