On the Normal Stress Dependence of the Shear Fracture Energy
On the Normal Stress Dependence of the Shear Fracture Energy
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关于剪切断裂能的法向应力依赖性
DOI：
10.1029/gm037p0001
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发表时间：
2013
影响因子：
3
通讯作者：
T. Wong
中科院分区：
文献类型：
--
作者：
T. Wong
剪切断裂能 G 已在实验室中通过使用相对较大的锯切样本的双轴测试或使用厘米大小的锯切或完整样本的三轴测试来确定。使用近似方案根据三轴试验的失效后变形数据确定恒定正应力条件下预期的滑移弱化行为。当应用于圣马科斯辉长岩的新结果以及已发表的菲希特尔山花岗岩结果时，这表明在恒定的正应力条件下，使用恒定围压下的三轴数据计算的剪切断裂能的标称值将减少约 2 倍。数据简化方案还可应用于三轴试验中获得的粘滑数据，并评估 G 的下限和上限。实验确定的 G 值比地震推断值低几个数量级。
The shear fracture energy G has been determined in the laboratory by biaxial tests using relatively large sawcut specimens or by triaxial tests using cm‐sized sawcut or intact specimens. An approximate scheme was used to determine the expected slip‐weakening behavior under constant normal stress condition from the post‐failure deformation data of triaxial tests. When applied to new results on San Marcos gabbro together with published results on Fichtelbirge granite, this shows that the nominal value of the shear fracture energy calculated using triaxial data at constant confining pressure would be reduced by about a factor of 2 under constant normal stress condition. The data reduction scheme can also be applied to stick‐slip data obtained in triaxial tests and lower and upper bounds on G were evaluated. The experimentally determined values of G are lower than the seismologically inferred values by orders of magnitude.