The Runup of a Tsunami (Seismic Sea Wave) on to a Shoreline

这项研究计划的目的是了解海啸对海岸线的影响。当海啸(地震产生的长波海浪)遇到海岸线时，可能会因洪水、大型物体漂浮、以及海浪或漂浮物对已建设施的影响。在评估对海岸线的潜在损害时，重要的参数是波浪爬升。有关海啸爆发的有用科学或工程信息很少。这项研究的目的是调查这一复杂现象的某些方面，首先研究作为海啸典型模型之一的椭圆形波的上升。这项研究包括在一个新的100英尺长的波浪水箱中进行分析建模和实验室实验。通过将这两种方法的结果与Boussinesq方程的数值模拟结果进行比较，试图确定色散、非线性、以及可能的耗散，导致了关于不同模型有效性的更简洁的信息。随后进行了初步的实验室调查，以确定与靠近海岸线的简单结构(如圆柱体和平面)上的椭圆形波运动有关的力。这些基础研究对海啸工程的潜在应用是对经常用于评估易受海啸破坏的海岸线地区的洪水的数值模型的校准，以及海啸预警系统的运作。

The aim of this research program is to understand the runup of a tsunami on to a shoreline. When a tsunami (a long wavelength sea wave generated by an earthquake) encounters a coastline, severe damage may result due to flooding, to the flotation of large objects, and to the impact of the wave or floating objects with constructed facilities. The parameter that is important in evaluating the potential damage to a coastline is the wave runup. Very little useful scientific or engineering information exists on the runup of tsunamis. The objective of this study is to investigate some aspects of this complex phenomenon, beginning with the study of the runup of a cnoidal wave, which is one quintessential model for tsunamis. This investigation involves analytical modeling combined with laboratory experiments in a new 100 foot long wave tank. By comparing the results from these two approaches with results from numerical simulations of the Boussinesq equations, an attempt is made to determine the relative effects of dispersion, nonlinearity, and possibly dissipation, leading to more concise information on the validity of different models. This is followed by a preliminary laboratory investigation to determine the forces associated with cnoidal wave motion on simple structures, such as cylinders and plane surfaces, close to the shoreline. Potential applications of these fundamental studies to tsunami engineering are in the calibration of numerical models which are frequently used in evaluating the flooding of coastline areas prone to tsunami damage, and in the operation of tsunami early-warning systems.