地下洞室脆性岩石断裂韧度巴西圆盘力学试验研究  

Research on Fracture Toughness of Brittle Rock in Underground Caverns Using Brazilian Disc Mechanical Tests

作　　者：王耘梓 孙宁 王龙 刘渊泽 余政兴 徐卫亚[1] WANG Yunzi;SUN Ning;WANG Long;LIU Yuanze;YU Zhengxing;XU Weiya(Geotechnical Research Institute,Hohai University,Nanjing 210098,China;PowerChina,Zhongnan Engineering Corporation Limited,Changsha 410014,China;Huaneng Lancang River Hydropower Inc.,Kunming 650214,China;Lancang River Clean Energy Security Green Intelligent Construction Technology Innovation Center of Xizang Autonomous Region,Kunming 650214,China)

机构地区：[1]河海大学岩土工程科学研究所,南京210098 [2]中国电建集团中南勘测设计研究院有限公司,长沙410014 [3]华能澜沧江水电股份有限公司,昆明650214 [4]西藏自治区澜沧江清洁能源安全绿色智能建设技术创新中心,昆明650214

出　　处：《三峡大学学报(自然科学版)》2025年第3期14-19,共6页Journal of China Three Gorges University:Natural Sciences

基　　金：国家自然科学基金重点项目(51939004);中国华能集团有限公司科技项目(HNKJ22-109)。

摘　　要：采用V形切槽巴西圆盘(cracked chevron notched brazilian disc, CCNBD)方法对大型水电站地下洞室花岗岩进行了劈裂加载试验,旨在研究不同含水率状态下岩石的断裂力学行为、断裂机制和裂纹扩展特征.试验结果表明,饱和状态下的花岗岩峰值荷载较干燥状态下的平均峰值荷载降低15.5%,平均峰值位移降低17.6%;在饱和状态下,花岗岩试样断裂韧度较干燥状态降低15.5%.裂纹起裂后,裂纹在韧带区迅速扩展,表现出以拉张应力为主的I型裂纹扩展模式.水的存在显著劣化了岩石试样的断裂韧度和降低吸收应变能的能力,含水状态下的围岩更易发生断裂破坏.研究结果为分析水电站地下洞室工程中的力学行为提供理论基础,并为大型地下洞室稳定性力学分析应用提供了技术支撑.The Cracked Chevron Notched Brazilian Disc(CCNBD)method was employed to conduct split tests on granite sampled from a large hydropower station underground cavern,to investigate the fracture mechanics behavior,fracture mechanisms,and crack propagation characteristics under different moisture contents.The results indicate that the peak load of saturated granite decreased by 15.4%compared to the average peak load in dry conditions,and the average peak displacement reduced by 17.7%.In saturated conditions,the fracture toughness of granite specimens decreased by 15.3%compared to dry conditions.After crack initiation,cracks rapidly propagate in the ligament zone,exhibiting a predominantly tensile stress-driven mode I crack propagation.The presence of water significantly deteriorates the fracture toughness of rock specimens and reduces their capacity to absorb strain energy,making the surrounding rocks more susceptible to fracture failure in moist conditions.These findings provide a theoretical foundation for analyzing the mechanica behavior in hydropower underground cavern engineering and offer technical support for the stability analysis of large underground caverns.

关 键 词：地下洞室 脆性岩石 花岗岩 V形切槽巴西圆盘 断裂韧度 断裂机制 

分 类 号：TV223[水利工程—水工结构工程]