Performance and functionality objectives in low to mid-rise buildings : a resilience study for wind hazards

Abstract

With an increasing frequency and severity of windstorms, design for resilience and achieving functional objectives for the built environment is becoming more critical. The concept of Performance objective assessment is recently extended to Wind Engineering. This approach is applied using the Database-Assisted Design technique, relying on the aerodynamic database provided by the National Institute of Standards and Technology (NIST). The procedure is then repeated for several wind directions and different dominant opening scenarios to determine the cases that meet or exceed performance objective criteria. A framework for recovery-based design in wind engineering is introduced. Currently, research is well advanced to implement this approach in earthquake engineering, with the scope of improving the resilience of structures, critical infrastructures (power plants and grid, water pipelines etc.), to achieve a durable and re-occupiable built environment after the occurrence of a disaster and to provide a tool to estimate the downtimes and quantify the service disruption. The concept of interdependencies between the nonstructural components and the building services is realized using Fault-Tree Analysis (FTA) and applied to four different hospitals with specific focus on the rooms in the zones assumed to be most vulnerable to wind damage. Two actual cases are analyzed that were damaged by hurricanes Maria in 2017, and Michael in 2018. The documentation of post-hazard damage is essential to develop and validate recovery models. In an effort to understand windstorm damage and its impact on recovery, a virtual damage detection and evaluation in post-windstorm reconnaissance is applied to a tornado that touched down in the city of Monroe, LA on April 12, 2020, causing damage to roughly 460 homes in addition to an estimated $250 million of property damage. Multiple reconnaissance teams documented the damage caused by this severe event by capturing video recordings from a drone and imagery from a vehicle-mounted camera. A Streetview application was created using the georeferenced panoramic images. Multiple evaluators reviewed datasets collected separately to determine a damage state and associated estimated wind speed using the current EF-Scale (WISE, 2006) and draft language from the EF-Scale chapter in the forthcoming ASCE/SEI/AMS standard on wind speed estimation. The large database of damage assessments then allowed comparisons between different evaluators, different modalities (ground-based and remote-sensing), and between the current and proposed revised EF-Scale. Particular attention is given to the limitations of each reconnaissance technology and the implications of each of the EF-Scales.