西安建筑科技大学学报(自然科学版)

使用水泥砂浆浇筑试样模拟含节理岩石,并设置不同角度的锯齿状节理,进行直剪试验研究其剪切力学特性,以及剪切强度与法向变化规律.试验结果显示,节理面的剪切破坏形式主要受锯齿角度控制,起伏角度较大的节理面,主要发生剪断破坏; 起伏角度较小的情况下则多发生磨损破坏.剪切过程中出现剪胀现象,并在低法向应力和较大锯齿角度下较明显.同一法向应力条件下,节理面抗剪强度基本符合Mohr-Coulomb准则,使用该准则对试验数据拟合得到内摩擦角和粘聚力与节理面锯齿角度呈正相关.分别用Patton和Ladanyi模型分析试验结果,前者在节理面锯齿起伏较小的情况下拟合结果较好,后者则相反.

Cement mortar samples with jagged joints of different angles were made to study their shear mechanical properties, shear strength and normal variation. The results show that the shear failure mode of the joint plane is mainly controlled by the sawtooth angle, the joint surface with larger angle mainly cause shear failure to and occur when the angle is gentle, wearing and tearing often occur. Shear dilatation occurs during the process, especially under lower normal stress and with sharp sawtooth angle. Under the same normal stress condition, the shear strength of the joint surface is positively correlated with the sawtooth angle. This basically meets the Mohr-Coulomb criterion. The cohesive force and internal friction angle of the joint surface obtained by fitting the criterion increase the sawtooth angle. Patton and Ladanyi strength models were used to data analysis. Results show that the former has a better fitting effect on the strength of the joint surface with smaller sawtooth angle, while the latter is better for fitting the joint surface with larger sawtooth angle.

引言
1 试验器材与方案
2 实验结果分析与讨论
3 强度公式对实验数据拟合结果
4 结论

表1 试验方案
Tab.1 Test plan

图1 节理面破坏形态<br/>Fig.1 Failureshape of triangular joints

图1 节理面破坏形态
Fig.1 Failureshape of triangular joints

图2 节理面两种剪切破坏形态<br/>Fig.2 Two shear destructions forms of joints

图2 节理面两种剪切破坏形态
Fig.2 Two shear destructions forms of joints

图3 15°锯齿节理面在不同法向应力条件下的剪切位移 - 应力曲线图<br/>Fig.3 Shear displacement-stress curve of joints with 15° sawtooth under different normal stress

图3 15°锯齿节理面在不同法向应力条件下的剪切位移 - 应力曲线图
Fig.3 Shear displacement-stress curve of joints with 15° sawtooth under different normal stress

图4 15°锯齿节理面在不同法向应力条件下的剪切位移 - 法向位移曲线图<br/>Fig.4 Shear displacement-normal displacement curve of joints with 15° sawtooth under different normal stress

图4 15°锯齿节理面在不同法向应力条件下的剪切位移 - 法向位移曲线图
Fig.4 Shear displacement-normal displacement curve of joints with 15° sawtooth under different normal stress

图5 45°锯齿节理面在不同法向应力条件下的剪切位移 - 应力曲线图<br/>Fig.5 Shear displacement-stress curve of joints with 45° sawtooth under different normal stress45°

图5 45°锯齿节理面在不同法向应力条件下的剪切位移 - 应力曲线图
Fig.5 Shear displacement-stress curve of joints with 45° sawtooth under different normal stress45°

图6 45°锯齿节理面在不同法向应力条件下的剪切位移 - 法向位移曲线图<br/>Fig.6 Shear displacement-normal displacement curve of joints with 45° sawtooth under different normal stress

图6 45°锯齿节理面在不同法向应力条件下的剪切位移 - 法向位移曲线图
Fig.6 Shear displacement-normal displacement curve of joints with 45° sawtooth under different normal stress

表2 不同法向应力下节理面抗剪强度<br/>Tab.2 Shear strength at different normal stresses

表2 不同法向应力下节理面抗剪强度
Tab.2 Shear strength at different normal stresses

图7 0.5MPa法向应力下不同角度节理面剪切应力 - 位移曲线<br/>Fig.7 Shear stress-displacement of joints with different saw tooth angle at normal stress of 0.5MPa

图7 0.5MPa法向应力下不同角度节理面剪切应力 - 位移曲线
Fig.7 Shear stress-displacement of joints with different saw tooth angle at normal stress of 0.5MPa

图8 0.5 MPa法向应力下节理面法向位移曲线对比<br/>Fig.8 Comparison of normal displacement of joints at normal stress of 0.5 MPa

图8 0.5 MPa法向应力下节理面法向位移曲线对比
Fig.8 Comparison of normal displacement of joints at normal stress of 0.5 MPa

图9 锯齿角度与节理面抗剪强度的关系<br/>Fig.9 Relationship between sawtooth angle and shear strength of joint

图9 锯齿角度与节理面抗剪强度的关系
Fig.9 Relationship between sawtooth angle and shear strength of joint

图10 使用Mohr-Coulomb准则的拟合曲线<br/>Fig.10 Fitting result of Mohr-Coulomb modeMohr-Coulomb

图10 使用Mohr-Coulomb准则的拟合曲线
Fig.10 Fitting result of Mohr-Coulomb modeMohr-Coulomb

图11 Patton和Ladanyi两种强度模型拟合比较<br/>Fig.11 Comparison of Patton and Ladanyi strength models fitting result

图11 Patton和Ladanyi两种强度模型拟合比较
Fig.11 Comparison of Patton and Ladanyi strength models fitting result

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备注

引言

1 试验器材与方案

2 实验结果分析与讨论

3 强度公式对实验数据拟合结果

4 结论

期刊信息