# Model Test on the Behaviors of Deep Excavation with Lateral Confined Water
## 1 Introduction
### Model Test System and Materials
During the setup of the strut, one side of the diaphragm wall is connected to the preset bolts on the long tube, and the exposed length of the screw rod is adjusted to ensure that the short tube connects with the preset bolts on the opposite side of the diaphragm wall. \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Soil** & \begin{tabular}{c} **Saturated** \\ **Density \(\rho_{\mathrm{sat}}\)** \\ **(\(\times\)10\({}^{3}\) kg/m\({}^{3}\))** \\ \end{tabular} & \begin{tabular}{c} **Elasticity** \\ **Modulus \(E_{s}\)** \\ **(MPa)** \\ \end{tabular} & \
\begin{tabular}{c} **Poisson Ratio \(\
u\)** \\ **Poisson Ratio \(\
u\)** \\ **\end{tabular} & \begin{tabular}{c} **Cohesion** \\ **c (kPa)** \\ **c (kPa)** \\ \end{tabular} & \
\begin{tabular}{c} **Internal** \\ **Friction Angle** \\ **(cm/s)** \\ \end{tabular} &
\begin{tabular}{c} **Horizontal** \\ **Permability** \\ **Permability** \\ **(cm/s)** \\ \end{tabular} \\ \hline Fine sand & 18.35 & 18 & 0.3 & 0 & 31.73 & 1.945 \(\times\) 10\({}^{-2}\) & 1.323 \(\times\) 10\({}^{-2}\) \\ \hline Clay & 19.08 & 5 & 0.4 & 24.08 & 25.30 & 4.767 \(\times\) 10\({}^{-7}\) & 3.898 \(\times\) 10\({}^{-7}\) \\ \hline \end{tabular} Note: The shear strength parameters are obtained through the undrained quick shear test.  
\end{table} 
Table 2: Basic material parameters of soil. Figure 3: Photo of diaphragm wall for model test. The water level control system consists of two parts: the lateral confined water level control system and the dewatering system within the excavation (Figures 2 and 5). The lateral confined water level control system includes a water tank, a water inlet pipe network, and a confined water level monitoring pipe. The water inlet pipe network is arranged parallel to the horizontal direction of the sidewall, symmetrically on both sides. The outlet of the water inlet pipe network is located within the lateral confined aquifer, and both inlets are connected to the same water tank. By adjusting the water level in the tank, the lateral confined water level can be regulated. Confined water level monitoring pipes, positioned at the top of the confined aquifer on both sides of the excavation, allow for the observation of the lateral confined water level within the sidewalls. The dewatering system inside the excavation consists of an in-pit dewatering pipe network, a peristaltic pump (BT300-1 FS, Baoding Lange Peristaltic Pump Co., Ltd., Baoding, China), and a phreate water level monitoring pipe. The rectangular dewatering network is placed 30 mm below the base of the excavation. The phreatic water level monitoring pipe on the sidewall is connected at one end to the in-pit pipe dewatering network, and at the other end to the peristaltic pump. During the dewatering process, the phreatic water level monitoring pipe functions as a pumping well, and when dewatering stops, it serves as a water level observation well. Both the water inlet pipe network and in-pit pipe dewatering network use PPR pipes (diameter 20 mm). Holes are drilled in the water inlet pipe network and in-pit dewatering pipe network, with geotextile wrapping around the pipes to prevent soil particles from blocking the network. The confined water level monitoring pipes and phreatic water level monitoring pipe are made of graduated glass tubes (diameter 6 mm). Figure 4: Photos of the strut for the model test: (**a**) before assembling: (**b**) after assembling. Figure 5: Photo of the water level control system for the model test.