Large-scale physical modeling of broken solitary waves impacting elevated coastal structures

ABSTRACT

Amongst extreme hydrodynamic events are bore- and surge-type flow motions that are observed in the context of storm surges induced by tropical cyclones, but also occur when tsunami or flash floods strike. Coastal houses built on elevated pile foundations have suffered less damages in recent extreme hydrodynamic events since the water could pass beneath the floor slabs decreasing the exertion of forces onto structures. To date, research pertaining to horizontal and vertical forces on elevated structures is still scarce. Specifically, previous research may not be applicable to cases of bore-type inundation interacting with elevated coastal structures. This work hence aims to model non-elevated and elevated coastal structure, and to deepen insight into forces with a focus on the structural elevation. For this purpose, large-scale experimental tests were performed on a uniform 1:15 slope in combination with an adjacent horizontal plane. Idealized residential buildings on a length scale of 1:5 were designed to simulate loading conditions of broken solitary waves on slab-on-grade and elevated buildings. A wide range of horizontal forces between 0.1 and 10 $kN$, vertical forces between 0.5 and 7.5 $kN$ and overturning moments up to 4.5 $kNm$ were measured. In accordance with the experimental results, design equations were derived.

KEYWORDS:

• Storm surge
• experimental modeling
• elevated coastal structures
• wave forces
• structural response
• tsunami

Acknowledgments

The authors are indebted to the technical staff at the Coastal Research Center, Hannover, and the Leichtweiß-Institute for Hydraulic Engineering and Water Resources who greatly eased conducting experiment at large-scale. The cost of operation of the large wave flume at Coastal Research Center is jointly covered by the Leibniz University Hannover and Technische Universität Braunschweig. The support of the Volkswagen Foundation (project ‘Beyond Rigidity - Collapsing Structures in Experimental Hydraulics,’ No. 93826) through a grant held by N. Goseberg is greatly acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Raw data were generated at the Coastal Research Center in Hannover, Germany. Derived data supporting the findings of this study are available from the corresponding author, Clemens Krautwald, on request.

Author credit

C. Krautwald: Methodology, Formal Analysis, Investigation, Visualization, Writing – Original Draft, Review & Editing, H. von Häfen: Methodology, Formal Analysis, Writing - Review & Editing, P. Niebuhr: Methodology, Writing - Review & Editing, K. Vögele: Methodology, Writing - Review & Editing, D. Schürenkamp: Writing - Review & Editing, Supervision, M. Sieder: Writing - Review & Editing, Supervision and N. Goseberg: Conceptualization, Writing - Review & Editing, Validation, Supervision, Project administration, Funding acquisition. All authors have read and agreed to the submitted version of the manuscript.

Additional information

Funding

This work was supported by the Volkswagen Foundation [93826].