Numerical modelling by the meshless method of smoothed-particle hydrodynamics can offer quantification of tsunami wave pressures at a greater level of detail and accuracy than existing empirical methods, enabling more effective design solutions to be derived. In this paper, smoothed-particle hydrodynamics modelling of tsunami wave and structure interaction is undertaken to derive the time histories of wave pressure distributions, which can then be used by way of finite-element software to evaluate the structural response. In a series of comparative studies with physical models, the numerical results show good agreement with the experimental data. The research in this paper forms part of a wider investigation that aims to address the issue of improving resilience of shore-based structures in tsunami events.

2 3A series of three-dimensional smoothed particle hydrodynamics (SPH) and finite-element (FE) models, with a domain in the form of a water tank, were undertaken to simulate tsunami-induced bore impact on a discrete onshore structure on a dry bed. The fluid motion was simulated using the SPH-based software DualSPHysics. The tsunami-like waves were represented by solitary waves with different characteristics generated by the numerical paddle wavemaker. Numerical probes were uniformly distributed on the structure's vertical surface providing detailed measures of the pressure distribution across the structure. The peak impact locations on the structure's surface were specifically determined and the associated peak pressures then compared with the prediction of existing commonly used design equations. Using the pressure-time histories from the SPH model, FE analysis was conducted with Abaqus to model the dynamic response of a representative timber structure. The results show that the equations used to estimate the associated pressure for design purposes can be highly non-conservative. By gaining a detailed insight into the impact pressures and structure response, engineers have the potential means to optimise the design of structures under tsunami impact loads and improve survivability. Notation

This paper explores the influence of onshore structures' orientations and arrangements during tsunami impact using the numerical method of smoothed particle hydrodynamics (SPH). Observations from previous tsunami events often reveal variation in the damage and survivability of impacted similar structures. Such variation can be due to shielding effects and other interactions that occur when the tsunami wave is incident upon an urbanised location. The SPH model used in this work was first validated against previous experimental results and was then used to explore the resulting hydrodynamic behaviour to a level of detail hitherto unobtainable from physical experiments. Groups of three and five structures were modelled with varying spatial separation and orientation to the incoming tsunami bore, characterised by the wake clearance angle (A) and the rotation angle (R), respectively. The results reveal significant reductions in total force on a structure can be made via strategic spatial positioning and orientation. Such reductions may mean the difference between superficial damage and wholesale structural collapse and allow the development of more resilient structures in tsunami-prone regions.

The confined masonry (CM) structure has been commonly used in the construction of one-story buildings in Indonesia. Its application for multi-story buildings however, is not yet as popular as the alternative options. This research numerically investigated the behavior of confined masonry and its application for use as the main structure of multi-story buildings subjected to seismic loading. From the validation models it was revealed that, using shell element for masonry walls, reinforced concrete beams and tie-columns, the CM model mimic the load deformation curve of tested specimen better than that using frame and shell elements. The application of the modeling technique for the design of 3-story residential building using wall density index less than that suggested in the literature resulted in a safe and stiff structure. The wall stresses under design seismic load were still less than the wall strength and the drift ratio of the model was 0.06% much smaller than the limit of 0.2%. The maximum stress observed at the corners of wall opening justify the need for confinement along the opening.

The diagrid structure system has become an encouraging alternative for the construction of tall buildings partly because of the aesthetic reason. Structurally, the system also interesting because its diagonal intersecting members are capable of resisting vertical and lateral forces efficiently. This research compared the design of steel tower building using diagrid (DIA) system and the more commonly used systems, moment frame (MF) and braced frame (BF). Numerical modelling using finite element software ETABS were conducted to design a 10-story building of 15x15m with total height of 50 meters. The seismic behaviors of all models were compared under the same loading conditions. From the analysis results the DIA model showed superior seismic behavior followed by BF and MF. The DIA model was not only stiffer than the others, but also required smaller volume of steel.

The resilience of buildings subject to tsunami bore impact can be improved by reducing tsunami-induced lateral hydrodynamic pressure by allowing part of the tsunami bore to pass through the buildings via openings and break-away walls. This research investigated the reduction of lateral pressure caused by tsunami bore impact on a low-rise residential building with openings proposed as the prototype of tsunami-resistant house. Numerical method using smoothed particle hydrodynamic (SPH)- based software called DualSPHysics was used to create simulation in numerical boundary in the form of a water tank. The tsunami-like bore simulations were generated based on dam-break analogy and were validated against experimental results. Four simulation cases were conducted in this study: Case 1 and Case 2 were dealing with the parameter sensitivity of reservoir height and distance between reservoir and building, while Case 3 and Case 4 were related to the effectiveness of openings and the base elevation of building in reducing wave impact pressures. The numerical modelling results show that the presence of openings and building’s base elevation significantly reduced the lateral hydrodynamic pressures on buildings up to 50% and this could become an effective strategy for improving the resilience of low-rise residential buildings under tsunami bore impact.

This study investigates the effectiveness of a new discrete V-shape coastal barrier (V-wall) to reduce multiple tsunami-bore impacts on a group of idealized coastal structures. The performance comparison has been made between a baseline model (BM), continuous straight wall models (SW) and V-wall (VW) models. A number of key parameters including the barrier height and length along with the arrangement of the landward structures are investigated numerically using the 3-D smoothed particle hydrodynamics (SPH) approach. From the SPH models output the bore velocity, maximum force, total impulse and pressure distribution on the structures are examined. The results indicate that the V-walls can provide a similar level of protection to continuous seawalls of the same height and hence can be considered as an economic alternative to protection in tsunami prone regions. However, in order to gain the greatest benefit from the V-walls, strategic planning of the position and orientation of landward structures and the walls themselves is needed to avoid bore flow focusing and reflection effects.

This study aims to analyze of the structural behavior of two-story building under the combination of earthquake forces and tsunami hydrodynamic forces, with model variations included the percentage of wall’s opening and thickness. The 3-D modeling of two-story buildings were conducted in this study using software SAP 2000; the first model consisted of wall panels with the percentage of openings of 0% (PD0), 25% (PD25), 35% (PD35), and 50% (PD50), while the second model included buildings with 150 mm and 250 mm wall thickness. In addition, the hydrodynamic force predicted by numerical simulations based on Smoothed Particle Hydrodynamic (SPH) was compared to that of predicted by semi-empirical design equations. The results of the wall panel modeling show that the greater the percentage of wall’s opening, the smaller the hydrodynamic load that can be carried out by the structure and hence, the lesser the stresses on the wall. The increase of building’s wall thickness from 150 mm to 250 mm under the combination of earthquake and tsunami loads decreased the stress on walls, moments and transverse forces. Conversely, the tensile and shear stresses on the walls were increased due to the combination of tsunami loads. The comparison of hydrodynamic force shows that the maximum force predicted by SPH was generally higher to that of predicted by the semi-empirical design equations.