# Study of the Effect of Cutting Frozen Soils on the Supports of Above-Ground Trunk Pipelines
## 3 Results
### Development of Above-Ground Trunk Pipeline Support Design
An experimental bench was constructed to evaluate the feasibility of the support design. The bench simulates the behavior of the support slab in soil when used to reinforce pipe supports. The simulator consists of a movable press with a cooling chamber, which applies pressure on the slab to simulate pipeline loads. A stationary personal computer (PC) was placed next to the press to set the required fracture stress and soil temperature values. A sharp-edged support slab was positioned under the loading press and its displacement was monitored by the PC. The reduced-scale support slab serves as a representative model of an actual support slab. The primary aim of the bench tests is to validate the effectiveness of the proposed support design. This involves determining the fracture stress of frozen expanded soil based on soil type and different temperatures, which are influenced by the climatic conditions in regions with permafrost rocks. For the experiment, a baseplate with sharp edge angles of 30 and 45 degrees was selected. The baseplate was 150 \(\times\) 80 mm in size and made of reinforced concrete, 170 mm long, with a concrete grade of M500. A steel press with a cooling chamber, two refrigerators, with freezing temperatures ranging from \(-4\)\({}^{\circ}\)C to \(-10\)\({}^{\circ}\)C, soil samples of different types (sand, clay, and loam), and a metal pipe with a diameter of 350 mm and a length of 500 mm were used. From practical application, it was determined that the angle should not be dull. Hence, for the experiment, angles of 30 and 45 degrees were selected as boundary conditions. An angle higher than 45 degrees is deemed ineffective due to its weak cutting effect while decreasing the angle below 30 degrees would result in a reduced support-bearing capacity. Hence, the specific boundary extreme angles of 30 and 45 degrees were established. The experimental setup (Figure 5) was designed to simulate the impact \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \begin{tabular}{c} **Characteristics** \\ **of Frozen** \\ **Ground** \\ \end{tabular} & \begin{tabular}{c} **Modulus of** \\ **Deformation,** \\ **kN/m2** \\ \end{tabular} & **Poisson’s Ratio** & **Cohesion, kPa** & \begin{tabular}{c} **Internal** \\ **Friction Angle** \\ \end{tabular} & \
\begin{tabular}{c} **Specific** \\ **Gravity of the** \\ **Soil, kN/m3** \\ \end{tabular} &
\begin{tabular}{c} **Porosity** \\ **Coefficient, d.** \\ **Units** \\ \end{tabular} \\ \hline Sand & 16,671,305 & 0.3 & 25 & 19 & 26.09 & 0.65 \\ \hline Clay & 2,941,995 & 0.4 & 45 & 15 & 26.87 & 0.65 \\ \hline Sandy loam & 11,473,780 & 0.31 & 24 & 13 & 26.48 & 0.65 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Characteristics of frozen expanded soil at \(-10\)\({}^{\circ}\)C.  
of soil frost heave forces on the support structure, with the goal of demonstrating the effectiveness of the structure by cutting the frost-heaving soil with the sharp edge of the support plate. The soil was frozen using refrigerators (Figure 6), where soil samples and reinforced concrete edges were placed for 24 h. The main objective of the bench tests was to confirm the effectiveness of the proposed method. This involved determining the fracture stress of the frost-heaving soil based on soil type and different temperatures, which are influenced by the climatic conditions in regions with continuous permafrost. Figure 3: Samples and materials for tests: (**a**)—sand; (**b**)—clay; (**c**)—a piece of metal pipe; (**d**)—scales: brand M-ER 333 AF-150.50 “FARMER” LCD, the maximum weighing limit of 150 kg, the accuracy of 50 g; (**e**)—ground with water (ambient temperature); (**f**)—reinforced concrete sharp edges with angles 30 and 45 degrees. During the full-scale experiments, the press was applied from above onto the support slab with a sharp edge, causing it to move down towards the frozen soil by a relative distance of 0.01 m. The forces required to fracture the frozen soil were captured and displayed on the computer screen.