Numerical Study for the Hydrodynamic Pressure on the Front of Onshore Structures by Tsunami

Large-scale experiments on tsunami-induced pressure on a vertical tide wall

“…The run-up force is observed during the transition between the impulsive and quasi-steady hydrodynamic forces and occurs due to the effects of the flipped water mass resulting from the bore impact. In a series of numerical studies (Kihara et al, 2012;Takabatake and Kihara, 2014;Takabatake et al, 2013), we have also observed the three-phase pressure pattern exerted on structures. A local maximum pressure was observed during the transition between the impulsive and quasi-steady phases, and we presumed that this local maximum pressure is caused by convergence of the upward flow accelerated by the continuous burst of the incident flow in low areas on the wall and the downward flow accelerated by gravity in high areas.…”

“…Bredmose et al (2009) referred to this pressure as "reflective pressure." In a series of numerical studies (Kihara et al, 2012;Takabatake and Kihara, 2014;Takabatake et al, 2013), we observed that a local high pressure occurred in this phase. We suggested that this local high pressure was caused by the convergence of upward flow, accelerated by the continuous burst of the incident flow in low areas, and downward flow, accelerated by gravity at high areas on the wall.…”

An Application of Semi-empirical Physical Model of Tsunami-Bore Pressure on Buildings

“…On the other hand, at buildings R3 and R4, which are located farther from the coast than R1 and R2, the maximum forces are observed after 4 s or more have passed since the tsunami impacted the buildings R3 and R4, and the maximum forces are lower than those of R1 and R2. As shown in Figure 11, the comparison of inundation depth and velocity at B6 and B1 shows that the inundation depth and the specific energy become lower as the distance from coastal line increases, resulting in the tsunami wave force being lower, as mentioned by our early studies (Kihara et al, 2012;Takabatake et al, 2013).…”

“…The tsunami wave forces that acted on the seaward side of buildings R1, R2, R3, and R4 are calculated by integrating pressures on the surface predicted by the coupling system of the semi-empirical physical model of bore pressure and the twodimensional simulation of the nSWE model, and are shown in Figure 12B. Here, for reference, pressures after the duration of the bore pressure are predicted by the evaluation method of quasi-steady-state pressure, which was proposed by early studies of authors (Kihara et al, 2012;Takabatake et al, 2013).…”