## 7 [PERSON]'s Method for Analyzing Core Logging  
The diameter restriction in RQD calculations was removed by [PERSON] [34] with the development of the C technique. You can use any diameter with the C factor. Following his measurements in Kiruna (Sweden), [PERSON] [35] reported his findings. The arithmetic mean of two parameters, the Cp sample factor and the Cm core length factor, is taken to determine the value of the computed fissuring factor (C). \[\mathrm{C=\frac{Cp+Cm}{2},} \tag{22}\]  
The Cp factor is similar to the RQD factor. It indicates how many samples are visible inside the intact core pieces or how many times the entire diameter of the core fits along the length of the piece. The length of the section being examined is divided by the product of the actual diameter and the number of samples that can be obtained to determine the sample factor. \[\mathrm{Cp=\frac{pD}{h_{b}-h_{a}},} \tag{23}\]  
Cm is calculated using the average lengths of the unbroken pieces of the core under investigation. It is important to measure each component precisely when calculating the core length factor. We are unable to determine the aperture or the areas with significant fractures by merely dividing the entire length by the number of fractures. \[\mathrm{Cm=\frac{\overline{m}}{h_{b}-h_{a}}} \tag{24}\]  
where:  
\[\overline{m}=\frac{\sum_{i=1}^{n}m_{i}}{n}=\frac{M}{n} \tag{25}\]  
Cm is substantially smaller than Cp because it is the ratio of the total length to the average length. It illustrates the joints of the rock bulk in this way. For instance, if the core is composed of entire segments around a diameter long, Cp may be artificially elevated. In this instance, Cm will be substantially smaller in order to adjust Kiruna's ultimate value. Using Formulas (22)-(24), one can determine the value of the fissuring factor (C). \[\mathrm{Cm=\frac{1}{2(h_{b}-h_{a})}\left(pD+\frac{M}{n}\right)} \tag{26}\]  
When calculating C, it is crucial to divide the core into pieces with comparable rock mechanical properties in order to obtain a clear view of each important component of the rock itself. It is also possible to acquire values for the fault zones and the block states. Kiruna's value can range from 0 to 1. When the unbroken portions are smaller than the core's diameter, C = 0. Rarely does C = 1 occur; it can only occur when the rock is solid and free of discontinuities. In this instance, it is difficult to distinguish between the rock mass and the block of rock since the core emerges in a single, long piece. Based on practical experience, a stratification system based on the C factor can also be used. According to [PERSON] [35], the C factor and RQD factor approaches are contrasted in the classification that follows (Table 9). [PERSON] et al. [36] compared the suggested method of [PERSON]'s C with the RQD method analyzing the core loggings of the Radioactive Waste Repository of Bataapati, Hungary. They found the following relationship between the two values (see Figure 17):  
* The linear approximation of the upper curve is the most accurate: \[\text{RQD}=222\text{ C}\] (27)
* The logarithmic equation can be used to describe the lower enclosing curve: \[\text{RQD}=65.28\text{ ln (C)}+98\] (28)  
We can observe from the curved lines that there are significant differences between the two approaches at extreme values. Kiruna's value (C) fluctuates between 0 and 0.22 at RQD = 0% and between 1 and 0.62 when RQD = 100%. The most jointed parts and the parts that the RQD method assumes are intact have this type of Kiruna variance. RQD falls between 0% and 10% or between 90% and 100% in these situations. It is impossible to establish a relationship due to the wide dispersion. Only the values between RQD 10% and 90% were examined in order to obtain a more accurate relationship. As a result, Figure 18 shows a linear relationship between the two approaches. \[\text{RQD}=175.75\text{ C}+2\text{ (\%)} \tag{29}\]  
More accurately than RQD, C displays the joint's presence even in the inspected area.