常规三轴条件下不均匀岩石的强度尺寸效应  

STRENGTH SIZE EFFECT OF HETEROGENEOUS ROCK IN CONVENTIONAL TRIAXIAL TESTS

作　　者：严妍[1] 郑永来[1] 曹宏泰[1] YAN Yan;ZHENG Yonglai;CAO Hongtai(College of Civil Engineering, Tongji University, Shanghai 200092, Chin)

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《低温建筑技术》2017年第12期130-133,共4页Low Temperature Architecture Technology

摘　　要：运用FLAC3D数值模拟软件对不均匀岩石在常规三轴条件下的强度尺寸效应进行了研究。细观单元的粘聚力和杨氏模量被假设为具有离散性并符合高斯分布,并通过设定不同的离散系数来反映岩样的不均匀程度。对不同尺寸的岩样在不同围压下进行多次加载得到了一系列具有离散性的试验结果。结果表明,随尺寸的增大,均匀的岩样没有尺寸效应,不均匀的岩样强度平均值会不断减小,离散系数则不断增大,而且岩样的不均匀程度越高,强度尺寸效应越显著;围压的增大则会降低岩样强度对尺寸变化的敏感性。通过定性分析认为,岩石强度的尺寸效应可以理解为岩石细观不均匀性在宏观上综合的平均效应。Numerical simulation soft Flac3D is used to study the strength size effect of heterogeneous rock in conventional triaxial tests. The cohesion and Young＇ s modules are assumed to be discrete and in accordance with the Gaussian distribution. Different variation coefficients are set to indicate the heterogeneity of rock specimens. After loading multiple times under different confining pressure, a series of dis- crete results are obtained. The simulation results show that： homogeneous rock specimens have no strength change with an increase in the size; for heterogeneous rock specimens, the average strengths de- crease while variation coefficients increase with the increase of size; the size effects are more prominent for more heterogeneous rock specimens ; The increase of confining pressure will decrease the sensitivity of rock specimens strength to the size change. Based on qualitative analysis, strength size effect could be considered as macroscopic ensemble averages of the heterogeneity of rock Specimens in the mesoscopic level.

关 键 词：岩石强度 尺寸效应 围压 不均匀性 平均效应 

分 类 号：TU317[建筑科学—结构工程]