中文摘要：

通过对人工模拟节理在不同法向应力作用下的4次反复直剪试验,分析节理峰值抗剪强度与反复剪切次数之间的关系以及节理粗糙度系数CJR退化与剪切次数之间的关系,并提出考虑反复剪切次数n的节理峰值强度公式和节理粗糙度系数CJR衰减的经验公式。研究结果表明：峰值强度随剪切次数的增加逐步减少,但第1次直剪试验得到的峰值抗剪强度与第2次直剪试验得到的峰值抗剪强度差异最明显,后3次直剪试验得到的峰值强度较接近;在相同的法向应力作用下,CJR随剪切次数的增加而减少,但减少速率逐步变小。

英文摘要：

Based on the shear tests of artificial rock joints under different normal stresses for four times,the relationship among the peak shear strength,shear test times and normal stress and between the roughness coefficient and shear test times were analyzed.A new shear strength criterion and roughness coefficient CJR degradation criterion were proposed considering the effects of both the normal stress and test times.The results show that the peak shear stress decreases gradually with the increase of the test times,and the difference is apparent between the first and the second time.The peak shear strengths of the last three times are close to each other.Under the same normal strength,CJR decreases with the increase of the test times,but the decrease rate is slower and slower.