## 3 Devices Setup and Field Test
### Design and Test of Horizontal Displacement Loading and Unloading Device  
The horizontal displacement loading and unloading device is composed of concrete reaction walls, hydraulic jacks, and concrete rods. The building measures 3586 m\({}^{2}\) in total size and weighs 5586 tons in total weight. Without taking earthquake and live loads into account, the building's true weight is approximately 3580 tons, or 1 ton/m\({}^{2}\). As seen in Table 1, the preyield stiffness of LRB400 is 10.44 kN\(\cdot\)mm\({}^{-1}\), the yield force Q\({}_{\text{d}}\) of the isolation bearing is 45 kN, and the isolation layer is composed of 26 LRB400, resulting in a total preyield stiffness of 271.44 kN\(\cdot\)mm\({}^{-1}\), and a total yield shear of 1170 kN. Twenty unreinforced concrete rods with a diameter of 180 mm \(\times\) 180 mm \(\times\) 600 mm and a strength grade of C30 were poured in advance, and each concrete rod had an axial pressure of up to 463.32 kN (180 mm \(\times\) 180 mm \(\times\) 14.3 N\(\cdot\)mm\({}^{-1}\)). Each reaction wall was constructed using four concrete rods for a total of sixteen rods, and the axial pressure can reach 7413.12 kN (463.32 kN \(\times\) 16), which is significantly greater than the isolation layer shear of 1170 kN. Three holes, each 20 mm in diameter, are reserved for the concrete rod to be used to implant the emulsion explosive. To guarantee that the concrete rod remains in powder form following the explosion without generating shards that would obstruct the displacement of the isolation layer, two rods were tested prior to the test, with a total of 6 g of emulsion explosive in each hole. Given the building site's suitable geological conditions and the relatively dense soil layer, four concrete reaction walls were poured in the north of the structure prior to the test. The construction of reaction wall requires less disturbance to the soil layer in order to obtain greater friction resistance. Calculations indicate that the concrete reaction wall is capable of withstanding the horizontal force required by the test. The reaction wall's top surface is sloped, and the overall cross section is trapezoidal, allowing for the placement of the loading device without compromising the exterior floor height. The layout of the reaction wall considers the balance of the left and right moments of the structure's center of mass, as illustrated in Figure 11. Figure 12 illustrates the schematic diagram of a test for loading and unloading the device. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sensor Type**} & \multicolumn{6}{c}{**Floor Location**} \\ \cline{2-9}  & **1 st Floor** & **2 nd Floor** & **3 rd Floor** & **Roof Floor** & **1 st Floor** & **2 nd Floor** & **3 rd Floor** & **Roof Floor** \\  & **Westward** & **Westward** & **Westward** & **Eastward** & **Eastward** & **Eastward** & **Eastward** \\ \hline Speed sensor & V1 & V2 & V3 & V4 & V5 & V6 & V7 & V8 \\ Acceleration sensor & A1 & A2 & A3 & A4 & A5 & A6 & A7 & A8 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Sensor numbers for each floor. Figure 10: Sensors configuration: (**a**) field layout of sensors; (**b**) floor layout of sensors. Twelve hydraulic lacks with a maximum load of 500 kN and a total output of 6000 kN were used in the test, with three hydraulic lacks on each reaction wall. The hydraulic jack is put against the reaction wall in advance of the test. Charging the hydraulic jack to induce gradual horizontal displacement of the upper structure. Figure 13 illustrates the schematic diagram used to apply the initial displacement. When the actual output of a single jack is 300 kN and the total output of 12 lacks is 3600 kN, it moves to the set displacement of 75 mm. At this point, the horizontal force applied to the building exceeds the yield force of the isolation layer by 1170 kN, indicating the lead core in the LRB has participated in the work [22]. Figure 14 illustrates the distorted isolation bearing.