## 5 Changes in Rock Properties with Increasing Freeze-Thaw Cycle
### Changes in Physical and Mechanical Properties of Rocks  
#### 5.3.1 Baseline Physical Properties of Rocks  
The physical properties of the initially sampled rocks are important reference data to provide the criteria for physical changes according to the freeze-thaw process and weathering grade. Baseline properties are defined in this study as reference rock sample properties prior to implement freeze-thaw cycles in laboratory. Table 2 shows the baseline (initial) values for porosity, absorption, P-wave velocity, shore hardness, and UCS of rocks in the northern region of Ny-Alesund. In order to determine the physical and mechanical properties of rocks, the methods proposed by the ISRM [38] are implemented. Figure 6 shows pictures of the measurement system for the tested samples. The physical and mechanical properties of three rock specimens from each location in the Ny-Alesund region are summarized  
Figure 5: Temperature change test inside the rock during freeze-thaw cycles. in Table 2. The rocks sampled at Location A relatively show lower porosity, absorption, and shore hardness and higher UCS and P-wave velocity than those properties of the rocks sampled at Location B. The extent of weathering of each specimen prior to application of freeze-thaw cycles was classified according to the existing grading method of [PERSON] [30]. The weathering grade proposed by [PERSON] and [PERSON] [30] classified rock grading into six categories (Table 3). When rock weathering was observed under a microscope, the rocks at Locations A and B showed relatively good preservation of texture and loss or change of colour, and so, in terms of weathering grade, the rocks were determined to be fresh. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Property**} & \multicolumn{3}{c}{**Location A**} & \multicolumn{3}{c}{**Location B**} \\  & **A-1** & **A-2** & **A-3** & **B-1** & **B-2** & **B-3** \\ \hline Porosity (\%) & 0.291 & 0.415 & 0.536 & 3.332 & 2.855 & 3.039 \\ Absorption (\%) & 0.106 & 0.151 & 0.195 & 1.298 & 1.136 & 1.184 \\ P-wave velocity (m/s) & 6266 & 6094 & 6048 & 4091 & 4390 & 4211 \\ Shore hardness & 62.9 & 66.2 & 63.8 & 87.7 & 90.3 & 85.0 \\ Uniaxial compressive strength (MPa) & 251.6 & 321.4 & 311.7 & 254.8 & 234.2 & 190.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Range of rock properties of the pre-test sample specimens. Figure 6: Photographs of measurement systems of rock properties: (**a**) Uniaxial compressive strength; (**b**) shore hardness; (**c**) absorption; (**d**) P-wave velocity. Although the rocks (prior to implement freeze-thaw cycles) in Locations A and B have the same weathering grade of \"fresh\" based on the methods of [PERSON] and [PERSON] [30], porosity and P-wave velocity were significantly different between the samples from Locations of A and B. Figure 7 shows the relationship between porosity and P-wave velocity in the specimens used in the freeze-thaw test. As shown in Figure 7, there exist clear differences in the physical properties in the relationship between porosity and P-wave velocity. This difference results from the different rock origins, internal structures, properties of minerals. There exists significant difference in porosity and P-wave velocity between rocks from Locations A and B. Figure 7 is provided to show a graphical view of the relationship between porosity and P-wave velocity. Dolomite, which is the smaller porosity, has the denser rock structure compared with quartzite. Therefore, the P-wave of dolomite is higher than that of quartzite.