标题：Experimental investigation of the mechanical behaviors of brittle rock materials containing en echelon boreholes
作者：Wu, Yue; Yang, Xu-Xu; Sun, De-Kang
作者机构：[Wu, Yue; Yang, Xu-Xu; Sun, De-Kang] Shandong Univ Sci & Technol, Shandong Key Lab Civil Engn Disaster Prevent & Mi, Qingdao 266590, Peoples R China.; 更多
通讯作者地址：Yang, XX (corresponding author), Shandong Univ Sci & Technol, Shandong Key Lab Civil Engn Disaster Prevent & Mi, Qingdao 266590, Peoples R China.; Yan 更多
来源：ARABIAN JOURNAL OF GEOSCIENCES
关键词：Failure behavior; Brittle rock material; En echelon boreholes;; Underground excavation
摘要：The borehole method is quite commonly utilized in underground excavation engineering, such as for mining and tunneling, to release high pressure in brittle rock materials for safety control. In this paper, with the purpose of better understanding the failure behavior of brittle rock material with en echelon boreholes, a series of uniaxial compression tests were carried out on sandstone samples in the laboratory. The geometric layout of boreholes was the focus in this study and varied in terms of the number of borehole rows and orientation. In accordance with the experimental results, three failure modes were observed to occur in the sandstone samples, which are tensile failure across the borehole row, tensile failure along the borehole row, and a mixed failure mode. The strength and deformability of sandstone samples are found to significantly depend on the layout of boreholes. The variation in the brittleness of the rock materials was also analyzed with respect to the ratio of the initial stress over peak stress. The findings of this study would enhance the understanding of the borehole method and provide guidance for underground excavation engineering.