| 摘要: |
| 根据直缝巴西圆盘(SNBD)试件计算应力强度因子的原理,设计组建了一套岩石丨、n型断裂钫性测试系统, 测定了岩石的I、n型断裂韧性，并与厚壁圆筒法的丨型断裂韧性测试值进行了比较。根据试验结果,分析了试样尺 寸、围压等因素对I、n型断裂韧性的影响。结果表明,研制的试验装置能够可靠地测出I、n型断裂韧性;试件厚 度最好大于30 mm,初始裂缝半长与圆盘半径的比o/R为0,1 3时,可很好地确定I、D型断裂韧性；I、II型断裂韧性测试值均有随围压增大而增大的趋势。 |
| 关键词: 岩石 试件 断裂韧性 水力压裂 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(50304010)和(9051005) |
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| Measurement of type-1 and type-H fracture toughness for rocks and its influence factors analysis |
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LOU Yi-shan, CHEN Mian, SHI Ming-yi, WANG Huai-ying
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(IHOE Key Laboratory of Petroleum Engineering in China University of Petroleum, Beijing 102249, China)
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| Abstract: |
| Based on the principle of cdculating the stress intensity factor of SNBD test piece, a fracture toughness test system for type-I and type-0 rocks was designed. The fracture toughness of type-I and type-U rocks was tested，and the results were compared with the results of type-I fracture toughness tested by thick-walled cylinder. According to the experimental data, the effects of sample size, confining pressure and other factors on the fracture toughness of type-I and type-11 rocks were analyzed- The results show that the fracture toughness of type-I and type-H rocks can be tested by this experimental device with higher accuracy. The sample thickness is greater than 30 mm, and the fracture toughness of type-1 and type-fl rocks can be determinwl when the ratio of initial fracture half-length to disc radius( a/R) ranges from (XI to 0. 3, The fracture toughness valuer of type-I and type-H rocks increase with the confinitig pressure increasing. |
| Key words: rock test piece fracture toughness hydraulic fracture |
