## 2 Methods
### Similarity Theory and Materials  
The model test is designed based on fundamental similarity theory, requiring that the relevant physical quantities of the model and prototype satisfy dimensional derivation equations [27]. The key physical quantities considered in the test include geometric dimensions \(L\), density \(\rho\), gravitational acceleration \(g\), elastic modulus \(E\), stress \(\sigma\), internal friction angle \(\varphi\), time \(t\), and permeability \(k\). Physical quantities \(L\), \(\rho\), and \(g\) were chosen as the basic physical quantities, with corresponding dimensions [L], [ML\({}^{-3}\)], and [LT\({}^{-2}\)], respectively. The similarity criterion function was obtained using the \(\pi\) theorem:  
\[\mathrm{f}(\pi_{1},\pi_{2},\pi_{3})=0, \tag{1}\]  
where, \(\pi_{1}=\frac{\sigma}{\rho Lg}\); \(\pi_{2}=\frac{k}{(lg)^{3}}\); \(\pi_{3}=\frac{t}{l^{3.5}g^{-0.5}}\)  
The prototype slope has a height of 142 m, and the model box is 1.7 m in length \(\times\) 0.45 m in width \(\times\) 0.8 m in height. The geometric similarity constant C\({}_{L}\) is controlled by the ratio of slope height to model box height (142/0.8 = 177.5). In order to facilitate the model construction, C\({}_{L}\) = 200 was determined. Given that the weight of the slope rocks is relatively high, the density similarity constant C\({}_{\rho}\) = 1.3 was selected based on existing research experience [28]. As the test is conducted under 1-\(g\) conditions, the gravitational acceleration similarity constant C\({}_{g}\) = 1 was determined. The similarity theory requires that the prototype and model similarity criteria are equal, allowing the remaining similarity constants to be calculated and summarized in Table 1. \begin{table}
\begin{tabular}{c c c} \hline
**Similarity Constant** & **Calculation Formula** & **Value** \\ \hline Stress \(\sigma\) & C\({}_{\sigma}\) = C\({}_{\rho}\)C\({}_{\mathrm{g}}\)C\({}_{L}\) & 260 \\ Cohesion \(c\) & C\({}_{c}\) = C\({}_{\rho}\)C\({}_{\mathrm{g}}\)C\({}_{L}\) & 260 \\ Elastic module \(E\) & C\({}_{E}\) = C\({}_{\rho}\)C\({}_{\mathrm{g}}\)C\({}_{L}\) & 260 \\ Friction angle \(\varphi\) & C\({}_{\rho}\) = 1 & 1 \\ Time \(t\) & C\({}_{t}\) = C\({}_{L}^{\mathrm{g}}\)C\({}_{g}^{-0.5}\) & 14.1 \\ Permeability coefficient \(k\) & C\({}_{k}\) = \(\big{(}\)C\({}_{L}\)C\({}_{g}\)\(\big{)}\(\big{)}\(\big{)}\(\big{)}\) & 14.1 \\ \hline \end{tabular}
\end{table} 
Table 1: Similar constants of derived physical quantities. Figure 1: The location of the water conservancy project and profile of the prototype slope: (**a**) Study area; (**b**) Geological profile of the bank dam slope. Based on existing similar material studies [29], barite powder, fine river sand, coarse river sand, and gypsum were selected to prepare similar materials. The physical and mechanical parameters and the proportion of the similar materials are shown in Table 2 and Table 3, respectively. Through the uniaxial compression and direct shear tests, the mechanical properties of the materials were determined (Figure 2a). Rainfall infiltration is controlled by the permeability of the material, and the permeability coefficient was tested according to the variable head test. The frame beams and retaining plate were made of 2 mm thick polypropylene plates (Figure 2b). disturbances and deformation transfer in anchored jointed rock blocks [33]. In this study, 3D-printed ITS and bolts (diameter: 3 mm) were assembled as ITS components to monitor slope stability. As illustrated in Figure 3a, ITS consists of a ring, a boss, and a sleeve. The maximum outer diameter of the boss and the inner diameter of the ring are both 12.0 mm. The boss has three ring grooves, and the outer diameters from top to bottom are 11.9 mm, 11.8 mm, and 11.7 mm, respectively. The ring is initially located in the uppermost ring groove. When the axial pressure is greater than a certain value, the ring will be detached and moved to the next ring groove. When the ring groove moves, the axial force drops sharply.