Landslide tsunami generation is a complex physical process that involves solid materials interacting with water bodies and other 3D nonlinear wave effects. Modeling of this process ranks as an urgent task because wave source features are crucial clues for subsequent tsunami motions and hazards threatening coastlines. Herein, we introduce a concept of ‘Push Ahead’ (PA) in landslide/water interactions and propose a PA formulation integrated in a meshless numerical procedure named ‘Tsunami Squares’ (TS) for modeling of landslide tsunami generation. We draw comparisons on the physical significances of PA acceleration versus ‘Drag Along’ (DA) acceleration and conventional aerodynamic and hydrodynamic solutions. We carry out physical experiments of wave generation by block-dragging and gravel flows and corresponding TS simulations to study PA effects in landslide/water interactions. Wave features in TS simulations match the experimental observations in a reasonable range, providing a firm validation of the PA formulation in the TS approach. Sensitivity analysis that compares simulations with various ratios of PA acceleration is carried out both for the block-dragging and gravel flow experiments. The comparisons indicate that PA acceleration plays an important role in landslide wave generation and that larger PA accelerations make greater contributions to the initial wave source. We discuss intrinsic relations between PA formulation and the empirical equations derived from previous experiment studies that support the validity and applicability of the PA solution. We also insist that the complex 3D wave effects such as dispersion, shoaling, refraction, reflection and superposition, occurring in the experiments can be well reproduced in the TS simulations. The newly proposed PA acceleration that works together with our previously presented ‘Drag Along’ and ‘Lift Up’ effects can excellently illustrate the mechanical process of landslide water interactions. We conclude that TS simulations that do not include the ‘Push Ahead’ acceleration can seriously underestimate landslide tsunami size.

滑坡海啸的产生是一个复杂的物理过程，涉及固体物质与水体相互作用以及其他3D非线性波效应。对这一过程进行建模是一项紧迫的任务，因为波源特征是随后海啸运动和威胁海岸线的危险的关键线索。在此，我们介绍了滑坡/水相互作用中的“向前推进”（PA）概念，并提出了一种集成在名为“海啸平方”（TS）的无网格数值程序中的PA公式，用于对滑坡海啸的产生进行建模。我们对PA加速与“沿阻力”（DA）加速以及常规空气动力和流体动力解决方案的物理意义进行了比较。我们通过块体拖动和砾石流进行了波产生的物理实验，并进行了相应的TS模拟，以研究PA在滑坡/水相互作用中的作用。TS模拟中的波动特征在合理范围内与实验观测值相匹配，从而为TS方法中的PA配方提供了可靠的验证。进行了块体拖动和砾石流实验，均进行了灵敏度分析，将模拟结果与不同比例的PA加速度进行了比较。比较表明，PA加速度在滑坡波的产生中起着重要作用，并且较大的PA加速度对初始波源的贡献更大。我们讨论了PA公式与经验公式之间的内在联系，这些经验公式来自先前的实验研究，这些经验证据支持PA解决方案的有效性和适用性。我们还坚持认为，可以在TS模拟中很好地再现实验中发生的复杂3D波效应，例如色散，浅滩，折射，反射和叠加。新近提出的PA加速与我们先前介绍的“拖曳”和“提升”效果一起可以很好地说明滑坡与水相互作用的机械过程。我们得出的结论是，不包括“向前推进”加速度的TS模拟可能会严重低估滑坡海啸的规模。在TS模拟中可以很好地重现实验中发生的情况。新近提出的PA加速与我们先前介绍的“拖曳”和“提升”效果一起可以很好地说明滑坡与水相互作用的机械过程。我们得出的结论是，不包括“向前推进”加速度的TS模拟可能会严重低估滑坡海啸的规模。在TS模拟中可以很好地重现实验中发生的情况。新近提出的PA加速与我们先前介绍的“拖曳”和“提升”效果一起可以很好地说明滑坡与水相互作用的机械过程。我们得出的结论是，不包括“向前推进”加速度的TS模拟可能会严重低估滑坡海啸的规模。