SCALE EFFECTS OF UNDULATION AMPLITUDE OF ROCK JOINTS

The characteristics of surface undulation profiles is an basic properties of rock joint roughness coefficient(JRC).Researching on variation of joint undulation amplitude helps to analyze the scale effects of joint roughness coefficient.In the text,through series of self-developed scale profilograph,measured various sizes of joint undulation amplitude.By statistics and analysis on variation of undulation amplitude with size of rock joint,the results showed that,undulation amplitude exists in scale effects,and there is different roughness coefficient measurement in the same direction but different Position.However,it has the same trend.The variation of medium-scale and large-scale of joint undulation amplitude increases with the size,and it will approach to different definite value with the increasing size.The average statistics of joint undulation amplitude presented good logarithmic function relationship with alternation sizes.