## 4 Experimental Results and Discussion  
### Test Observation  
Tests RW1-1, RW1-2, and RW1-3 were tested in sequence. For RW1-1, at the loading drift level of 0.5%, the visible grout near the wall footings cracked slightly, and the wall-footing connection decompressed with the wall panels detached from the foundation. As the rocking wall was connected to the foundation through the infill grout, the phenomenon indicated that the rocking wall began to rotate at the wall toe. Simultaneously, the SEDPs initiated shear deformation with a measured relative displacement of 2.45 mm. As there was mutual misalignment between the two wall panels, the SEDPs could be considered to work between the individual walls. The SEDPs yielded at the loading drift level of 0.67%, of which the shear displacement approached 5.88 mm. The phenomenon indicated that the configuration realizes the original design concept for the energy dissipation of the system. The wall panel could be observed to rotate around the wall toe. A sound was heard near the bolts connecting the SEDP during the 2% drift loading process, which was attributed to the result of the slip between the nut and the SEDP. At the end of the test, the SEDPs were removed, and traces of nut slippage were observed, as shown in Figure 8a. Following the drift level exceeding 2%, significant cracking of the grout between wall panels and foundation was observed, as shown in Figure 8b. There was little damage found in the two wall panels, while the SEDPs exhibited irreversible residual plastic deformation. Since the SEDP is designed as replaceable in the future application, the specimen could be regarded to fail as expected. Test RW1-2 was loaded second. In addition to SEDPs, Test RW1-2 was fitted with MBSFs with additional Belleville springs. The purpose of RW1-2 was to verify the possibility of utilizing multiple energy dissipaters to achieve HED. Since the grout had lost its bonding capacity, the wall panels lifted, overcoming only the pressure on the wall-footing connection due to the tension of the PT strands and the self-weight of the wall panels at the beginning of the second test. Similar to Test RW1-1, the newly installed SEDPs also yielded at the 0.67% loading drift level. As the loading drift level increased, the Belleville springs were compressed continuously, and they were fully compressed before 1.0% loading drift, which meant that the MBSFs became involved and the specimen entered the second mechanical stage. The residual deformation of the MBSFs gradually developed at the later stage of the test, and the cores buckled at the pressurized side of the specimen. Therefore, the central energy dissipation core of the MBSF was stuck in the confining tube due to the restraining effect after the test, as shown in Figure 8c. Figure 7: Loading protocol. Figure 8: Test observation. (**a**) Traces of nut slippage; (**b**) Cracking of the grout; (**c**) Plastic deformation of MBSF; (**d**) Cracks in RW1-3. Note that the specimen was loaded to check the behaviors with large SEDPs causing minor damage of the concrete at wall toes before Test RW1-3 [41]. The damage potentially caused the loss in the bearing capacity of the specimen to some degree. As for Test RW1-3, since no Belleville spring was installed, the SEDPs could enter operational status once the wall panels detached from the foundation beam at the drift level of 0.5%, while the wall panels commenced to misalign, leading to the shear deformation of the SEDPs. Both energy dissipaters yielded by loading to 0.67% drift level, and with MBSF, the corresponding drift for yielding was much less than that for RW1-2. Narrow horizontal cracks appeared on both sides of the wall specimen at the later stage of Test RW1-3. Figure 8d shows the cracks in the wall panel on the tensioned side when loaded positively up to the 2% drift level. The cracks close automatically as the loading drift unloads to zero due to the prestressing strands.