scholarly journals DEVELOPMENT OF TSUNAMI INUNDATION EVALUATION METHOD CONSIDERING DAMAGE LEVEL OF SEAWALL

2018 ◽  
pp. 77
Author(s):  
Katsumi Seki ◽  
Taro Arikawa ◽  
Kenichiro Shimosako ◽  
Tomohiro Takagawa ◽  
Yu Chida
Keyword(s):  
Numerical Simulation ◽  
Monte Carlo ◽  
Evaluation Method ◽  
Numerical Models ◽  
Destruction Process ◽  
Tsunami Inundation ◽  
Damage Level ◽  
Inundation Area ◽  
Inundation Depth ◽  
Subduction Zone Earthquake

Against the huge tsunami with the subduction-zone earthquake, structures such as breakwater and seawall are constructed. The expected effects of these structures are to reduce the inundation depth and inundation area. In other words, if we estimate tsunami inundation using numerical simulation accurately, it is necessary to reflect the situation of these structures in the numerical models. However in the present technology, it is difficult to predict while to estimate and reflect the destruction process by earthquake and tsunami attack. In this study, we assume that the damage level of structures are uncertain phenomenon and we develop that evaluated the tsunami inundation stochastically using Monte Carlo method.

scholarly journals Development of a Practical Evaluation Method for Tsunami Debris and Its Accumulation

2022 ◽  
Vol 12 (2) ◽  
pp. 858
Author(s):  
Kentaro Imai ◽  
Takashi Hashimoto ◽  
Yuta Mitobe ◽  
Tatsuo Masuta ◽  
Narumi Takahashi ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Evaluation Method ◽  
Thickness Distribution ◽  
Empirical Evaluation ◽  
Practical Method ◽  
Tsunami Disaster ◽  
Fragility Function ◽  
Inundation Area ◽  
Inundation Depth ◽  
Accumulation Trend

Tsunami-related fires may occur in the inundation area during a huge tsunami disaster, and woody debris produced by the tsunami can cause the fires to spread. To establish a practical method for evaluating tsunami-related fire predictions, we previously developed a method for evaluating the tsunami debris thickness distribution that uses tsunami computation results and static parameters for tsunami numerical analysis. We then used this evaluation method to successfully reproduce the tsunami debris accumulation trend. We then developed an empirical building fragility function that relates the production of debris not only to inundation depth but also to the topographic gradient and the proportion of robust buildings. Using these empirical evaluation models, along with conventional tsunami numerical analysis data, we carried out a practical tsunami debris prediction for Owase City, Mie Prefecture, a potential disaster area for a Nankai Trough mega-earthquake. This prediction analysis method can reveal hazards which go undetected by a conventional tsunami inundation analysis. These results indicate that it is insufficient to characterize the tsunami hazard by inundation area and inundation depth alone when predicting the hazard of a huge tsunami; moreover, more practically, it is necessary to predict the hazard based on the effect of tsunami debris.

scholarly journals Numerical Simulation of Tsunami Inundation in Urban Areas

2006 ◽  
Vol 1 (1) ◽  
pp. 148-156 ◽  
Author(s):  
Tetsuya Hiraishi ◽  
◽  
Tomohiro Yasuda ◽  
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Simulation Model ◽  
Urban Areas ◽  
Tokyo Bay ◽  
Tsunami Inundation ◽  
Model City ◽  
Inundation Depth ◽  
The Pacific ◽  
Potential Damage

The population and property in urban areas facing waterfronts is rapidly increasing together with the probability that a huge tsunami will occur on the Pacific Rim. The huge potential damage reflects the need to develop a highly accurate simulation model for tsunami inundation to help mitigate tsunami effects. We developed a simulation model to estimate the inundation depth and speed of tsunamis in urban areas. The model was applied to calculate the vari- ation of inundation areas in a model city facing Tokyo Bay. Experiments of tsunami inundation in the model city on a 1/50 scale was carried out for validation of the numerical model.

scholarly journals PHYSICAL MODEL OF TSUNAMI-LOADS ON A SEASIDE BUILDING ARRAY

2020 ◽  
pp. 2
Author(s):  
Naoto Kihara ◽  
Taro Arikawa ◽  
Masashi Watanabe ◽  
Hideki Kaida ◽  
Fumiya Murase ◽  
...  
Keyword(s):  
Numerical Models ◽  
Benchmark Test ◽  
Tsunami Inundation ◽  
Wave Pressure ◽  
The Past ◽  
Inundation Depth ◽  
Benchmark Tests ◽  
Evaluation Models ◽  
Building Array ◽  
Debris Impact

The devastating damage to buildings and infrastructure caused by the 2011 Tohoku-oki earthquake and tsunami highlighted the importance of evaluating tsunami impacts in areas at risk of tsunami inundation for disaster prevention and mitigation. Evaluation technologies have been vigorously researched and developed over the past decade. A wide variety of numerical models exist that can potentially be applied to evaluate tsunami impacts. Furthermore, several either theoretical or empirical models to evaluate tsunami impacts, such as evaluation models of debris impact force and tsunami wave pressure, have been proposed. To validate these numerical and evaluation models, both experimental and theoretical benchmark tests have been conducted (e.g., Horrillo et al., 2015). Most of these tests have been conducted to validate models of tsunami generation, propagation, and inundation. However, the number of benchmark tests to validate tsunami loads are limited, and especially, those for complex terrains are rare. In this study, as a benchmark test to validate modeling of tsunami inundation and wave pressure, hydraulic experiments of tsunami inundations were conducted over a seaside area model, in which building arrays were installed. The inundation depth, velocity, and pressure were numerically predicted for the condition of the benchmark test, and then compared with the measured data for validation.

Probabilistic multiscale modeling of fracture in heterogeneous materials and structures

2020 ◽  
Vol 86 (7) ◽  
pp. 45-54
Author(s):  
A. M. Lepikhin ◽  
N. A. Makhutov ◽  
Yu. I. Shokin
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Fracture Mechanics ◽  
Multiscale Modeling ◽  
Virtual Work ◽  
Numerical Models ◽  
Heterogeneous Materials ◽  
Heterogeneous Structure ◽  
Generalized Coordinates ◽  
Heterogeneous Structures

The probabilistic aspects of multiscale modeling of the fracture of heterogeneous structures are considered. An approach combining homogenization methods with phenomenological and numerical models of fracture mechanics is proposed to solve the problems of assessing the probabilities of destruction of structurally heterogeneous materials. A model of a generalized heterogeneous structure consisting of heterogeneous materials and regions of different scales containing cracks and crack-like defects is formulated. Linking of scales is carried out using kinematic conditions and multiscale principle of virtual forces. The probability of destruction is formulated as the conditional probability of successive nested fracture events of different scales. Cracks and crack-like defects are considered the main sources of fracture. The distribution of defects is represented in the form of Poisson ensembles. Critical stresses at the tops of cracks are described by the Weibull model. Analytical expressions for the fracture probabilities of multiscale heterogeneous structures with multilevel limit states are obtained. An approach based on a modified Monte Carlo method of statistical modeling is proposed to assess the fracture probabilities taking into account the real morphology of heterogeneous structures. A feature of the proposed method is the use of a three-level fracture scheme with numerical solution of the problems at the micro, meso and macro scales. The main variables are generalized forces of the crack propagation and crack growth resistance. Crack sizes are considered generalized coordinates. To reduce the dimensionality, the problem of fracture mechanics is reformulated into the problem of stability of a heterogeneous structure under load with variations of generalized coordinates and analysis of the virtual work of generalized forces. Expressions for estimating the fracture probabilities using a modified Monte Carlo method for multiscale heterogeneous structures are obtained. The prospects of using the developed approaches to assess the fracture probabilities and address the problems of risk analysis of heterogeneous structures are shown.

scholarly journals Flood Inundation Assessment in the Low-Lying River Basin Considering Extreme Rainfall Impacts and Topographic Vulnerability

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 896
Author(s):  
Thanh Thu Nguyen ◽  
Makoto Nakatsugawa ◽  
Tomohito J. Yamada ◽  
Tsuyoshi Hoshino
Keyword(s):  
River Basin ◽  
Extreme Rainfall ◽  
Flood Damage ◽  
Water Levels ◽  
Flood Inundation ◽  
Inundation Area ◽  
Inundation Depth ◽  
Study Results ◽  
Inundation Duration ◽  
Short Time

This study aims to evaluate the change in flood inundation in the Chitose River basin (CRB), a tributary of the Ishikari River, considering the extreme rainfall impacts and topographic vulnerability. The changing impacts were assessed using a large-ensemble rainfall dataset with a high resolution of 5 km (d4PDF) as input data for the rainfall–runoff–inundation (RRI) model. Additionally, the prediction of time differences between the peak discharge in the Chitose River and peak water levels at the confluence point intersecting the Ishikari River were improved compared to the previous study. Results indicate that due to climatic changes, extreme river floods are expected to increase by 21–24% in the Ishikari River basin (IRB), while flood inundation is expected to be severe and higher in the CRB, with increases of 24.5, 46.5, and 13.8% for the inundation area, inundation volume, and peak inundation depth, respectively. Flood inundation is likely to occur in the CRB downstream area with a frequency of 90–100%. Additionally, the inundation duration is expected to increase by 5–10 h here. Moreover, the short time difference (0–10 h) is predicted to increase significantly in the CRB. This study provides useful information for policymakers to mitigate flood damage in vulnerable areas.

scholarly journals Influence of Coastal Topography on Tsunami Inundation Area

2011 ◽  
Vol 67 (2) ◽  
pp. I_256-I_260
Author(s):  
Shigeru KATO ◽  
JUNAIDI ◽  
Takumi OKABE ◽  
Shin-ichi AOKI
Keyword(s):  
Tsunami Inundation ◽  
Inundation Area ◽  
Coastal Topography
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