Tsunami Generation by Submarine Mass Failure. I: Modeling, Experimental Validation, and Sensitivity Analyses
Tsunami Generation by Submarine Mass Failure. I: Modeling, Experimental Validation, and Sensitivity Analyses
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DOI：
10.1061/(asce)0733-950x(2005)131:6(283
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发表时间：
2005-11
期刊：
影响因子：
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通讯作者：
S. Grilli;P. Watts
中科院分区：
文献类型：
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作者：
S. Grilli;P. Watts
数值模拟与二维（2D）完全非线性势流（FNPF）模型的海啸生成的两种理想类型的潜艇质量故障（SMF）：水下幻灯片和滑塌。这些模拟具有刚性或变形SMF，具有高斯横截面，沿平面斜率向下平移。在每种情况下，SMF质心运动表示为几何，流体动力学和材料参数的函数，下面一个简单的造波器形式主义，并规定为边界条件的FNPF模型。海啸振幅和爬高是从计算的自由表面高程。模型结果进行了实验验证的刚性2D幻灯片。进行敏感性研究，以估计SMF的形状，类型和初始淹没深度对所产生的海啸的影响。一个强大的SMF变形运动过程中显着增强海啸的生成，特别是在远场。典型的滑坡所产生的海啸比相应的滑坡要小。海啸振幅和助跑强烈依赖于初始SMF淹没深度。对于选定的SMF理想化的几何形状，这种依赖性简单地表示为幂律。其他的敏感性分析在一个配套文件，从数值模拟的结果转换成经验曲线拟合预测特性海啸振幅作为无量纲的管理参数的函数。应该强调的是，这些经验公式只适用于海啸源附近，由于问题的复杂性，有必要进行许多简化。它进一步显示在配套文件中如何二维结果可以被修改，以占三维海啸的产生，并用于快速估计海啸灾害或进行简单的案例研究。
Numerical simulations are performed with a two-dimensional (2D) fully nonlinear potential flow (FNPF) model for tsunami generation by two idealized types of submarine mass failure (SMF): underwater slides and slumps. These simulations feature rigid or deforming SMFs with a Gaussian cross section, translating down a plane slope. In each case, the SMF center of mass motion is expressed as a function of geometric, hydrodynamic, and material parameters, following a simple wavemaker formalism, and prescribed as a boundary condition in the FNPF model. Tsunami amplitudes and runup are obtained from computed free surface elevations. Model results are experimentally validated for a rigid 2D slide. Sensitivity studies are performed to estimate the effects of SMF-shape, type, and initial submergence depth—on the generated tsunamis. A strong SMF deformation during motion is shown to significantly enhance tsunami generation, particularly in the far-field. Typical slumps are shown to generate smaller tsunamis than corresponding slides. Both tsunami amplitude and runup are shown to depend strongly on initial SMF submergence depth. For the selected SMF idealized geometry, this dependence is simply expressed by power laws. Other sensitivity analyses are presented in a companion paper, and results from numerical simulations are converted into empirical curve fits predicting characteristic tsunami amplitudes as functions of nondimensional governing parameters. It should be stressed that these empirical formulas are only valid in the vicinity of the tsunami sources and, because of the complexity of the problem, many simplifications were necessary. It is further shown in the companion paper how 2D results can be modified to account for three-dimensional tsunami generation and used for quickly estimating tsunami hazard or for performing simple case studies.