# Smart Deployable Scissor Lift Brace to Mitigate Earthquake Risks of Soft-Story Buildings
## 5 Conclusions  
The soft-story mechanism is a long-standing problem affecting many existing buildings where the ground level has a much smaller lateral stiffness compared to that of the rest of the building. There has been no attempt in the literature to utilize the newly developed Earthquake Early Warning (EEW) system to solve this problem. This paper presents a novel EEW-activated deployable scissor lift system specifically aimed at solving such a problem. When no earthquake is detected, the scissor lift brace system remains retracted in the basement of the building, preserving the building's open floor plan without causing any obstructions. The system features an onboard microcontroller that continuously awaits the signal from the EEW. Upon receiving a signal, indicating imminent ground motion, the scissor lift brace deploys and anchors itself to the ceiling of the ground level, enhancing its lateral stiffness and strength to withstand strong earthquake forces. Once the ground motion ceases, the deployed system is retracted, returning to its initial state. This process is fully automated and repeatable. The proposed system provides an alternative retrofit solution to soft-story buildings. It retains the intended open ground level which the traditional means of strengthening, such as the addition of permanent braces, are unable to do.  
In a proof-of-concept laboratory experiment, a single-degree-of-freedom test model was fabricated. The model was equipped with a communication module and a microcontroller to deploy a scissor lift brace. Actuation was delivered by a DC motor through a threaded shaft. A simulated EEW signal triggered its deployment. The Quanser Shake Table 2 was utilized to simulate ground vibrations. The parameters from four historical earthquakes were used as input excitations. A single-story test model was tested when the (1) scissor lift brace system was in its undeployed state and when the (2) EEW triggered the deployment of the scissor lift brace. The results demonstrate that there was an increase in the vibrational responses at the roof level but also a significant decrease in inter-story drifts (79-93% reduction) when the brace was deployed.  
The proposed system is suitable for buildings which suffer from the soft story mechanism, where excessive deflection is expected at the ground level due to low lateral stiffness. The experimental results show that a significant reduction in the inter-story drift was achieved when the scissor lift brace system was deployed. It signifies improved structural performance, reduced risk of catastrophic failure, enhanced safety for the occupants, and an increased overall resilience. This is a crucial measure of the effectiveness of any retrofitting or strengthening measures applied to such buildings.  
Several issues related to the full-scale implementation of this system are also discussed, including the system's physical and electrical requirements, cybersecurity concerns, and the need for a fail-safe activation mechanism. These factors are important for potential integration with the Internet of Things (IoT) concept. The implications for future structural retrofits are discussed, and the limitations of the proposed system are also discussed in the article.  
Conceptualization, V.R. and R.W.K.C.; methodology, V.R. and R.W.K.C.; validation, V.R. and R.W.K.C.; formal analysis, V.R. and R.W.K.C.; writing--original draft preparation, V.R.; writing--review & editing, R.W.K.C.; visualization, V.R. and R.W.K.C.; supervision, R.W.K.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The raw data supporting the conclusions of this article will be made available by the authors upon request.  
**Conflicts of Interest:** The authors declare no conflicts of interest.