Experimental study on forces exerted on buildings with openings due to extreme hydrodynamic events

Abstract

Previous studies and field surveys showed that specific structural designs can decrease the load on free-standing buildings along the coast, providing safer vertical shelters. This experimental study investigated the effect of openings in buildings (windows, doors and foyers) on horizontal forces and tilting moments induced by both dry bed surges and wet bed bores. Four configurations with seven porosity values ranging from 0% (impervious) to 84% (highly permeable) were systematically tested. Due to the presence of openings, the flow through the building reduced the upstream water depths. The porosity resulting from the presence of openings was shown to produce a linear reduction of the maximum horizontal force, when compared to the corresponding impervious building. The configuration with an impervious back showed results similar to those measured for the fully impervious buildings. The occurrence of the maximum tilting moment was shown to coincide with the maximum horizontal force and an estimation of the cantilever arm was therefore possible. The latter was constant for all configurations, independent of the geometry of the openings. Finally, two equations to predict the maximum horizontal force and the tilting moment were proposed, taking into account the effect of building openings within the resistance coefficient. These showed good agreement with experimental data and previous studies. These findings provide engineers with practical information for the design of safer vertical shelters in tsunamiprone areas.

Effect of Debris Damming on Wave-Induced Hydrodynamic Loads against Free-Standing Buildings with Openings

“…In addition, except for the recent contribution of Stolle et al (2018b), most previous studies only focused on one type of debris and the behavior of mixtures with different debris shapes and sizes has not been analyzed. In line with the research conducted by Wüthrich et al (2018b) for free-standing buildings with openings, the present work investigates the effect of two types of debris on the resulting loads exerted on a free-standing building with openings. Particular attention is given to the post-peak hydrodynamic forces induced by the accumulation of debris in front of the openings.…”

“…The presence of debris within the flow modified the structural loading as compared to that of "pure" water waves described by Wüthrich et al (2018b) for identical buildings (with openings). As shown in Figure 9, the arrival of the wave is characterized by initial impact forces, followed by a more constant and sustained load, herein identified as the hydrodynamic force, in line with Yeh et al (2015).…”

“…where the interval 0 to 100•(d0/g) 0.5 was chosen herein as it represented the maximum duration that allowed to capture the loading process before the decrease of the wave became predominant. The impulse consideration have the advantage of being less affected by the randomness of the process compared to peak values (Bullock et al 2007;Wüthrich et al 2018b). The normalized impulse is shown in Figure 11 as a function of the retention coefficient Beff.…”

“…The impact of such waves on impervious free-standing buildings was the object of a number of research projects, providing engineers with tools to design resistant infrastructures. Triatmadja and Nurhasanah (2012) focused on the effect of openings in the building, and Wüthrich et al (2018b) showed that a flow through the buildings resulted into lower wave-induced forces and reduced inundation depths.…”

Experimental Study on Extreme Hydrodynamic Loading on Pipelines. Part 1: Flow Hydrodynamics

“…Nouri et al [29], Al-Faesly et al [30], Bremm et al [31] and Foster et al [32] evaluated the forces induced from tsunami-structure interaction under unsteady conditions. Other studies such as Wüthrich et al [33,34] investigated the extreme hydrodynamic forces induced on buildings with various characteristics. Arnason [35] studied the interaction between an incident bore and a free-standing structure and focused on analyzing flow hydrodynamics in their presence.…”