## 2 Torque Transmission Mechanism and Experimental Scheme
### Design and Fabrication of the Experimental Scale Model
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Prototype Size** & \multirow{2}{*}{**Scale Ratio**} & \multirow{2}{*}{**Theoretical Scaled**} & \multirow{2}{*}{**Actual Size of**} \\  & & **(mm)** & & **Size (mm)** & **Scale Model (mm)** \\ \hline \multirow{6}{*}{Foundation ring} & Top flange thickness & 102 & 1:3 & 34 & 34 \\  & Inner diameter of top flange & 3834 & 1:3 & 1278 & 1278 \\  & Outer diameter of top flange & 4200 & 1:3 & 1400 & 1400 \\  & Sidewall thickness & 28 & 1:3 & 9.33 & 10 \\  & Inner diameter of side wall & 4144 & 1:3 & 1381.33 & 1380 \\  & Outside diameter of sidewall & 4200 & 1:3 & 1400 & 1400 \\  & Number of oval holes in the sidewall & 52 & 1:1 & 52 & 52 \\  & Sidewall oval hole size & \(100\times 50\) & 1:3 & \(33.33\times 16.67\) & \(33\times 16.50\) \\  & Bottom flange thickness & 65 & 1:3 & 21.67 & 22 \\  & Inner diameter of bottom flange & 3922 & 1:3 & 1307.33 & 1307 \\  & Outer diameter of bottom flange & 4422 & 1:3 & 1474 & 1474 \\ \hline \multirow{2}{*}{Reinforcement} & Diameter of stressed steel bar & 28 & 1:3 & 9.33 & 10 \\  & Structural steel diameter & 18 & 1:3 & 6 & 6 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Calculation of foundation ring and reinforcement. Considering that the research object of this paper is the foundation ring, only the pillars and some concrete in the vicinity were built. The column and pressure beam templates were made with steel mold, the steel bars were fabricated according to design drawings, the strain gauges and pressure boxes were installed at the corresponding positions of the foundation ring, and the reinforcing bars and the concrete meter were installed at the corresponding positions of steel bars. Lastly, concrete pouring was conducted after the foundation ring had been located. In order to eliminate the bonding effect between the sidewall and the concrete, formwork paint was applied to the sidewall of the foundation ring, as shown in Figure 5b. In the design process, it is generally believed that the torque load on the top of the foundation ring is all borne by the bottom flange of the foundation ring, together with the top radial reinforcement. The adhesion between the sidewall of the foundation ring and the concrete is not considered but taken as a safety reserve. In order to be consistent with the basic design assumptions and considering that the objective of this paper is to study the distribution ratio of the torque load between the radial reinforcement on the top of the foundation and the bottom flange of the foundation ring, the inner and outer sides of the sidewall were painted with template paint and lubricant during fabrication. Notably, lubricating oil was applied as much as possible to eliminate the adhesion between the sidewall and the concrete, as shown in Figure 5b. However, the bonding effect cannot be completely eliminated in practice. Figure 4: Four test specimens of the 1:3 scale foundation ring: (**a**) ZT-1, with the original size of a standard scale specimen; (**b**) ZT-2, with reduced foundation ring depth; (**c**) ZT-3, with reduced width and thickness of foundation ring flange; (**d**) ZT-4, with reduced strength grade of concrete (mm). Figure 5: (**a**) Fabrication of the experimental scale model and (**b**) basic treatment of the ring sidewall.