It has been researched in the past four decades since Barton introduced the joint roughness coefficient (JRC) .
As we know in rock mechanics, the joint roughness coefficient (JRC) of rock joints contains the indeterminacy in different sampling lengths and directions of rock joints  and then results in the indeterminacy of the shear strength of joints due to the corresponding relationship between JRC and the shear strength.
Here, original roughness profiles (J1, J2, J3, and J4) were provided as an illustrative example and applied for analyzing the relationship between the joint roughness coefficient and their sample sizes, as shown in Figure 7.
Clearly, the neutrosophic function JRC(L) can indicate the range of the JRC values and show its effectiveness in the JRC analysis between the joint roughness coefficient and their sample sizes.
Zhang, "A new method estimating the 2D Joint Roughness Coefficient for discontinuity surfaces in rock masses," International Journal of Rock Mechanics and Mining Sciences, vol.
He has also presented the values of normal and shear stiffness of rock joints, as well as joint roughness coefficient.
On the basis of laboratory studies performed together with Choubey (Barton and Choubey, 1977), Barton finally stated that maximum shear strength on the joint surface also depends on the Joint Wall Compressive Strength (JCS) and Joint Roughness Coefficient (JRC), according to the following formula:
Table 2 presents the change in joint roughness coefficient for the three consecutive shear tests, namely with an increase in normal stress applied, as described in Section 2.
Most of the models address joint roughness in different ways such as Barton (1977) termed this parameter as Joint Roughness Coefficient JRC.
Barton and Choubey (1977) presented their updated version of empirical criterion for joint shear strength based on Joint Roughness Coefficient JRC as given by equation 3.
Joint roughness coefficient is the term in Barton model that is addressed in many researches.
For Barton model joint roughness coefficient (JCS) is obtained from the comparison of joint wall roughness with standard profiles its value is 12 for all the samples.