# Smart Deployable Scissor Lift Brace to Mitigate Earthquake Risks of Soft-Story Buildings
## 3 Proof-of-Concept Experimental Investigation  
### Experimental Setup and Instrumentation  
To demonstrate the feasibility of the proposed system, a proof-of-concept experimental investigation is described herein. Considering the payload capacity of the Quanser Shake Table II, a lightweight single-story structure made of aluminium, bakelite plastic, and steel was fabricated for the experimental investigation. Four columns, consisting of 8 mm diameter galvanized threaded rods, were connected to 10 mm bakelite boards which simulated the floors and roof. The open first floor measured 505 mm \(\times\) 500 mm \(\times\) 432 mm (height). Beneath the open first floor, a box made of bakelite boards measuring 505 mm \(\times\) 500 mm \(\times\) 100 mm was positioned. The top board of this box included two slits allowing a deployable scissor lift to protrude and attach itself to the roof during deployment. This box also housed other mechanical components and electrical connections, and the box was secured to the shake table. To simulate the weight of the upper floors, steel weight discs were placed on the roof. Each disc weighed 1.5 kg, and five of them were used (total mass of 7.5 kg). The scissor lift mechanism was constructed using 18 mm \(\times\) 18 mm \(\times\) 1.5 mm thick aluminium square tubes connected through pinned joints, designed to fit the height and width of the open ground floor. An 18 mm threaded rod was used to elevate the scissor lift. This actuator was connected to a circular bar with wooden circles at both ends, attached to either side of the scissor lift arrangement. A 12 VDC motor was selected to provide the rotary motion for the actuator, enabling the scissor lift to lift itself upon receiving earthquake alerts from the EEW system. A two-piece magnet door stopper was used to lock  
Figure 6: Rood displacement response in the numerical example. the scissor lift to the roof of the open first floor, preventing any movement of the scissor lift mechanism during the shaking. The experimental setup is depicted in Figures 7-9. It was secured on a Quanser Shake Table II, which simulated the ground motion in one direction, aligned with the open first floor. Figure 7 shows the structure when the scissor lift brace was completely retracted (i.e., service condition). Figure 8 shows a top view of the box containing the motor, scissor lift brace, and electronics. Figure 9 shows the structures when the scissor lift brace was deployed and attached to the ceiling of the roof. The responses of the frame were measured independently by two accelerometers (PCB Peizotronics model 603C01, acquired in Melbourne, Australia) positioned at the base (top of the box) and roof levels of the open first floor. The data acquisition (DAQ) device used was a National Instrument NI9234 (acquired in Melbourne, Australia), and the sampling rate used was 1 kHz. In addition, two non-contact laser displacement sensors (Micro-Epsilon model optoNCDT ILR 2250, sourced in Melbourne, Australia), one pointed at the roof and the other pointed at the base of the box measured the displacement during the shaking. Their displacement difference was used as the inter-story drift. Figure 8: Overview of the experimental setup—top view. Figure 7: Overview of the experimental setup—service condition. The shake table was controlled via MATLAB SIMULINK (version R2017b), and an algorithm was used to determine the desired position of the shake table, ensuring that the measured accelerations matched the recorded values. Each earthquake history was repeated twice:  
* Scissor lift brace undeployed--when the scissor lift was undeployed, the building had an open first floor representing the soft-story effect. Laterally, it was a single-degree-of-freedom system with a fundamental natural frequency of 1.5 Hz determined by the experimental modal analysis. * Scissor lift brace deployed--when the scissor lift brace was deployed, the open first story gained additional stiffness to mitigate the soft-story effect.