scholarly journals An efficient two-layer landslide-tsunami numerical model: effects of momentum transfer validated with physical experiments of waves generated by granular landslides

2021 ◽  
Vol 21 (4) ◽  
pp. 1229-1245
Author(s):  
Martin Franz ◽  
Michel Jaboyedoff ◽  
Ryan P. Mulligan ◽  
Yury Podladchikov ◽  
W. Andy Take

Abstract. The generation of a tsunami by a landslide is a complex phenomenon that involves landslide dynamics, wave dynamics and their interaction. Numerous lives and infrastructures around the world are threatened by this phenomenon. Predictive numerical models are a suitable tool to assess this natural hazard. However, the complexity of this phenomenon causes such models to be either computationally inefficient or unable to handle the overall process. Our model, which is based on shallow-water equations, has been developed to address these two problems. In our model, the two materials are treated as two different layers, and their interaction is resolved by momentum transfer inspired by elastic collision principles. The goal of this study is to demonstrate the validity of our model through benchmark tests based on physical experiments performed by Miller et al. (2017). A dry case is reproduced to validate the behaviour of the landslide propagation model using different rheological laws and to determine which law performs best. In addition, a wet case is reproduced to investigate the influence of different still-water levels on both the landslide deposit and the generated waves. The numerical results are in good agreement with the physical experiments, thereby confirming the validity of our model, particularly concerning the novel momentum transfer approach.

2020 ◽  
Author(s):  
Martin Franz ◽  
Michel Jaboyedoff ◽  
Ryan P. Mulligan ◽  
Yury Podladchikov ◽  
W. Andy Take

Abstract. A landslide-generated tsunami is a complex phenomenon that involves landslide dynamics, wave dynamics and their interaction. Numerous lives and infrastructures around the world are threatened by these events. Predictive numerical models are a suitable tool to assess this natural hazard. However, the complexity of this phenomenon causes such models to be either computationally inefficient or unable to handle the overall process. Our model, which is based on shallow water equations, is developed to address these two problems. In our model, the two materials are treated as two different layers, and their interaction is resolved by momentum transfer inspired by elastic collision principles. The goal of this study is to demonstrate the validity of our model through benchmark tests based on physical experiments performed by Miller et al. (2017). A dry case is reproduced to validate the behaviour of the landslide propagation model using different rheological laws and to determine which law performs the best. In addition, a wet case is reproduced to investigate the influence of different still water levels on both the landslide deposit and the generated waves. The numerical results are in good agreement with the physical experiments, thereby confirming the validity of our model, particularly concerning the novel momentum transfer approach.


Author(s):  
Michael CH Yam ◽  
Ke Ke ◽  
Ping Zhang ◽  
Qingyang Zhao

A novel beam-to-column connection equipped with shape memory alloy (SMA) plates has been proposed to realize resilient performance under low-to-medium seismic actions. In this conference paper, the detailed 3D numerical technique calibrated by the previous paper is adopted to examine the hysteretic behavior of the novel connection. A parametric study covering a reasonable range of parameters including the thickness of the SMA plate, friction coefficient between SMA plate and beam flange and pre-load of the bolt was carried out and the influence of the parameters was characterized. In addition, the effect of the SMA Belleville washer on the connection performance was also studied. The results of the numerical study showed that the initial connection stiffness and the energy-dissipation capacity of the novel connection can be enhanced with the increase of the thickness of the SMA plate. In addition, the initial connection stiffness and energy-dissipation behavior of the novel connection can be improved by increasing the friction coefficient or pre-load of bolts, whereas the increased friction level could compromise the self-centering behavior of the connection. The hysteretic curves of the numerical models of the connection also implied that the SMA washers may contribute to optimizing the connection behavior by increasing the connection stiffness and energy-dissipation capacity without sacrificing the self-centering behavior.


Author(s):  
Volker Roeber ◽  
J. Dylan Nestler ◽  
Jonas Pinault ◽  
Assaf Azouri ◽  
Florian Bellafont

Phase-resolving numerical models are a powerful tool to identify and analyze dominant wave processes along a site of interest. We have carried out a numerical study related to infra-gravity wave dynamics along the French Basque coast. The computed scenarios are representative for the swell conditions at the site of interest and include variations in offshore wave height, direction, and water level. Several statistical methods were employed that illustrate that the irregular bathymetry is a key component for the strong variations in sea-swell and IG-wave energy. The water level is demonstrated to substantially affect the IG-wave behavior, more than the wave direction. Swash oscillations in the IG-frequency band are greater than or equal to sea-swell swash oscillations at nearly all locations along the studied shoreline.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/ELZwJCokkX0


Author(s):  
Robin Middelanis ◽  
Sven Norman Willner ◽  
Christian Otto ◽  
Kilian Kuhla ◽  
Lennart Quante ◽  
...  

Abstract Tropical cyclones range among the costliest disasters on Earth. Their economic repercussions along the supply and trade network also affect remote economies that are not directly affected. We here simulate possible global repercussions on consumption for the example case of Hurricane Sandy in the US (2012) using the shock-propagation model Acclimate. The modeled shock yields a global three-phase ripple: an initial production demand reduction and associated consumption price decrease, followed by a supply shortage with increasing prices, and finally a recovery phase. Regions with strong trade relations to the US experience strong magnitudes of the ripple. A dominating demand reduction or supply shortage leads to overall consumption gains or losses of a region, respectively. While finding these repercussions in historic data is challenging due to strong volatility of economic interactions, numerical models like ours can help to identify them by approaching the problem from an exploratory angle, isolating the effect of interest. For this, our model simulates the economic interactions of over 7,000 regional economic sectors, interlinked through about 1.8 million trade relations. Under global warming, the wave-like structures of the economic response to major hurricanes like the one simulated here are likely to intensify and potentially overlap with other weather extremes.


2021 ◽  
Author(s):  
Grant Ferguson ◽  
Mark Cuthbert ◽  
Kevin Befus ◽  
Tom Gleeson ◽  
Chandler Noyes ◽  
...  

<p>Groundwater age and mean residence times have been invoked as measures of groundwater sustainability, with the idea that old or "fossil" groundwater is non-renewable. This idea appears to come from the link between groundwater age and background recharge rates, which are also of questionable use in assessing the sustainability of groundwater withdrawals. The use of groundwater age to assess renewability is further complicated by its relationship with flow system geometry. Young groundwaters near recharge areas are not inherently more renewable than older groundwaters down gradient. Similarly, there is no reason to preferentially use groundwater from smaller aquifers, which will have smaller mean residence times than larger aquifers for the same recharge rate. In some cases, groundwater ages may provide some information where groundwater recharge rates were much higher in the past and systems are no longer being recharged. However, there are few examples where the relationship between depletion and changes in recharge over long time periods has been rigorously explored. Groundwater age measurements can provide insights into the functioning of groundwater flow systems and calibration targets for numerical models and we advocate for their continued use, but they are not a metric of sustainable development. Simple metrics to assess groundwater sustainability remain elusive and a more holistic approach is warranted to maintain water levels and environmental flows.</p>


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2337
Author(s):  
Reza Azimi ◽  
Abdorreza Vaezihir ◽  
Robert Lenhard ◽  
S. Hassanizadeh

We investigate the movement of LNAPL (light non-aqueous phase liquid) into and out of monitoring wells in an immediate-scale experimental cell. Aquifer material grain size and LNAPL viscosity are two factors that are varied in three experiments involving lowering and rising water levels. There are six monitoring wells at varying distances from a LNAPL injection point and a water pumping well. We established steady water flow through the aquifer materials prior to LNAPL injection. Water pumping lowered the water levels in the aquifer materials. Terminating water pumping raised the water levels in the aquifer materials. Our focus was to record the LNAPL thickness in the monitoring wells under transient conditions. Throughout the experiments, we measured the elevations of the air-LNAPL and LNAPL-water interfaces in the monitoring wells to obtain the LNAPL thicknesses in the wells. We analyze the results and give plausible explanations. The data presented can be employed to test multiphase flow numerical models.


Author(s):  
Joaquín Moris ◽  
Patricio Catalán ◽  
Rodrigo Cienfuegos

Wave breaking is one of the main forcing mechanisms in coastal hydrodynamics, driving mean water levels and currents. Understanding its behavior is key in the goal of improving our comprehension of coastal morphodynamics variations. One way to improve our understanding is through the use of numerical models, such as phase-resolving numerical models based on the Boussinesq equations (Kirby, 2016), which are modified to include breaking by the inclusion of a breaking criteria and a dissipation mechanism. Since there is not a universal law capable of characterizing the wave breaking, the existing models must be calibrated. Traditionally, this is done by adjusting wave height profiles and other free surface statistical parameters without explicitly considering the time-space location and duration of the breaking process. Consequently, it is possible to calibrate a model that accurately represents wave elevation statistics parameters, such as wave height and wave set-up; however, it might not necessarily represent the breaking location-duration and therefore, the forcing.


2014 ◽  
Vol 567 ◽  
pp. 724-729 ◽  
Author(s):  
Indra Sati Hamonangan Harahap ◽  
Vo Nguyen Phu Huan

Submarine landslide is the most serious threat on both local and regional scales. Tsunami phenomenon induced by submarine slide has put us on the challenge in understanding from generation mechanism to propagation and coastal inundation and mitigating the risk from it. Submarine slides can trigger tsunamis with high run-up affecting offshore structures, subsea facilities and human lives along the shoreline. Unfortunately, there are no effective numerical models that could simulate simultaneously all stages of generation, propagation and run-up of tsunamis phenomena. This paper presents a comprehensive review on the landslide tsunami phenomenon.


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