Elevated structures are prevalent along shorelines that are susceptible to storm surge flooding to improve coastal resilience. In this work, we explore the influence of front wall inclination on the pressures and forces attracted by an elevated structure in response to extreme wave impact. Multiphase smoothed-particle hydrodynamics (SPH) was used to examine a typical two-story building 6 m high and 10 m long with three different frontal wall inclinations impinged by a single breaking wave propagating landwards (from left to right). Relative to a vertical surface, both positive (clockwise) and negative (counterclockwise) inclinations of the front wall altered breaking wave pressures depending on the structure's position relative to the still-water level (SWL). When the bottom of the structure is located below the SWL (negative air gap), a positive inclination decreased breaking wave loads by up to 21 %, while a negative inclination may result in 50 % higher pressure maxima. However, for a structure elevated above the SWL (positive air gap), negative and positive inclinations witnessed reductions to the pressure maxima of 35 % and 10 %, respectively, when compared with a vertical surface.

Relevant Publications

Pawitan, K. A., Garlock, M., Wang, S. (2024). Multiphase SPH analysis of a breaking wave impact on elevated structures with vertical and inclined walls. Applied Ocean Research, 142

Pawitan, K. A., Garlock, M., Wang, S. (2024). Effects of wall inclination on elevated structures subject to breaking waves: a multiphase SPH numerical exploration. Engineering Mechanics Institute Conference, Chicago, Illinois

We present a radical rethinking of conventional coastal armor via the development of “Kinetic Umbrellas” inspired by the architecture of master builder Félix Candela. Unlike traditional floodwalls or levees which rely on sheer mass alone, Kinetic Umbrellas are remarkably thin shells that utilize the double curvature of hyperbolic paraboloids (hypar) to resist surge and wave forces associated with landfalling tropical cyclones. As a kinetic structure, these umbrellas only deploy into an impermeable barrier prior to imminent hazard scenarios but remain a canopy during normal weather such that beach access is not impeded.

A decoupled numerical scheme constituting smoothed particle hydrodynamics (SPH) and finite element modeling (FEM) was leveraged for the structural analysis of deployed Kinetic Umbrellas under arbitrary hydrodynamic forcing. It was revealed that the effects of double curvature dramatically reduces out-of-plane stresses that typically limit the performance of thin shells. Hydrodynamic modeling confirmed that Kinetic Umbrellas proved structurally viable against surge inundation and wave attack consistent with Hurricane Sandy (2012) at Monmouth Beach, NJ. A simulation is shown here.

This research has been recognized by the American Society of Civil Engineers via the Moisseiff Award and has gained domestic and international media attention such as:

• USA Today

• Gizmodo

• Cosmos

• NewSphere (in Japanese)

Relevant Publications

Wu, G., Garlock, M., Wang, S. (2022). A Decoupled SPH-FEM Analysis of Hydrodynamic Wave Pressure on Hyperbolic-Paraboloid Thin-shell Coastal Armor and Corresponding Structural Response. Engineering Structures, 268

Wang, S., Garlock, M., Deike, L., Glisic, B. (2022). Feasibility of Kinetic Umbrellas as deployable flood barriers during landfalling hurricanes. Journal of Structural Engineering (ASCE), 148 (5)

Wang, S., Garlock, M., Glisic, B. (2021). A mechanism for the deployment of Kinetic Umbrellas for coastal hazard adaptation. Proceedings of the IASS Annual Symposium, Guilford, United Kingdom

Wang, S., Notario, V., Garlock, M., Glisic, B. (2021). Structural parameterization of Kinetic Umbrellas under hydrostatic inundation. Proceedings of the IASS Annual Symposium, Guilford, United Kingdom

Wang, S., Garlock, M., Glisic, B. (2021). Kinematics of deployable hyperbolic paraboloid umbrellas. Engineering Structures, 244

Wang, S., Notario, V., Garlock, M., Glisic, B. (2021). Parameterization of hydrostatic behavior of deployable hypar umbrellas as flood barriers. Thin-Walled Structures, 163

Wang, S., Garlock, M., Glisic, B. (2021). Parametric modeling of depth-limited wave spectra under hurricane conditions with applications to Kinetic Umbrellas against storm surge inundation. Water, 13

Wang, S., Garlock, M., Glisic, B. (2020). Hydrostatic response of deployable hyperbolic-paraboloid umbrellas as coastal armor. Journal of Structural Engineering (ASCE), 146 (6)

Wang, S., Garlock, M., Glisic, B. (2019). Kinetic Umbrellas for coastal defense applications. Proceedings of the IASS Annual Symposium, Barcelona, Spain