Breakwater subjected to tsunami–impact: Physical modelling of geotechnical phenomena. Issue 159 (August 2022)

• Record Type: Journal Article
• Authors: Jones, L.; Anastasopoulos, I.
• Is Part Of: Soil dynamics and earthquake engineering. Issue 159(2022)
• Publication Date: 2022-08
• Subjects: Tsunami -- Scour -- Physical modelling -- PIV -- Natural hazards; Soil dynamics -- Periodicals; Earthquake engineering -- Periodicals; Sols -- Dynamique -- Périodiques; Génie parasismique -- Périodiques; 624.176205
• DOI: 10.1016/j.soildyn.2022.107344
• Languages: English
• ISSNs: 0267-7261

Abstract

Abstract: As dramatically demonstrated by the failure of Tsunami-resistant breakwaters during the 2011 Tohoku earthquake, the behavior of structures subjected to Tsunami-impact is not fully understood. This paper studies experimentally the behavior of a simplified breakwater subjected to Tsunami-impact using a novel Miniaturized Tidal Generator (MTG). The response is monitored through a combination of image analysis and a unique instrumented-breakwater that allows direct measurement of the developing forces. Experiments reveal strong coupling between the scour-feature, the hydrodynamic forces acting on the breakwater, and its mechanical behavior. Upon overtopping, a plane-jet of water falling at an inclined trajectory results in progressive undermining of the foundation. Measurements reveal that the commonly assumed simple sliding-type failure on level-ground is difficult to promote. The failure mechanism consists of combined ( V H M ) bearing capacity failure due to combination of loss of support, hydrodynamic loading, and buoyancy effects. Highlights: Combined geotechnical and hydraulic mechanisms lead to Tsunami breakwater failure. Tsunami impact leads to hydrodynamic loading, buoyancy effects, and scour. Scour induced loss of support leads to combined (VHM) bearing capacity failure. Changes in both soil state and geometry are observed through image analysis. Direct measurement of forces acting on the breakwater reveals deeper insights.