Design of Vertical Evacuation Building at Painan City Using Results From Tsunami Propagation Modeling

Fault under the Mentawai Islands has high potential to cause a large earthquake and triggering tsunami. Painan City, is located near the fault. With geographical condition on a bay surrounded by hills in the upstream area, a tsunami may cause a flow channeling effect and increase the inundation distance. An alternative of mitigation effort is to build a Vertical Evacuation Building (VEB) to help the community to reach a safe elevation within the evacuation time. Therefore, VEB should be designed to withstand tsunami impacts and to resist large earthquakes. This study conducts the design and analysis of the performance of multi-functional VEB structures at Painan City. The tsunami propagation simulation was carried out, and parameters obtained were used for structural design. Three VEB models were developed, i.e., (i) model with walls under tsunami and earthquake loads, (ii) model without walls under tsunami and earthquake loads, and (iii) model without walls under earthquake load only as the lateral load. Non-linear static pushover analyses were later conducted to evaluate the structural performances. The study revealed that debris force affects the most compared to other tsunami force components. Structural openings also affect the tsunami load received by the structure. Column moment force for models designed with tsunami load is greater than that of earthquake, while the difference is less significant for beam. The internal force differences occur along the tsunami inundated depth, thus influence the component design. From the pushover analysis, all models were found to meet the performance targets for earthquake.