scholarly journals TINJAUAN GAYA TSUNAMI PADA JEMBATAN KRUENG RABA

2020 ◽  
Vol 3 (2) ◽  
pp. 177-185
Author(s):  
Mahfuz Mahfuz ◽  
Mochammad Afifuddin ◽  
Renni Anggraini
Keyword(s):  
Lift Force ◽  
Hydrodynamic Force ◽  
Steel Frame ◽  
Tsunami Height ◽  
Tsunami Disaster ◽  
Bridge Model ◽  
Hydrostatic Force ◽  
Collision Force ◽  
2004 Tsunami ◽  
Debris Impact

Aceh Province is located in one of the earth's fault lines in Indonesia, which is an area prone to earthquakes and the potential for a tsunami disaster. Therefore, any planning of structures located on the coast must consider the potential for a tsunami to obtain a strong structure to withstand the forces affected by the tsunami. During the 2004 tsunami, many bridges were carried away by the tsunami. Both bridges made of concrete, as well as steel frame bridges, such as the Krueng Raba steel frame bridge, Lhoknga, the Krueng No bridge, the Meunasah Kulam bridge, and several other bridges. This study aims to analyze and calculate the force and load effects of the tsunami on the structure of one of these bridges, namely the Krueng Raba steel frame bridge, Lhoknga. The force and load of the tsunami effect (Ts) will be analyzed by adopting the Guidelines for Design of Structures for Vertical Evacuation from Tsunamis, 2012, namely: (1) hydrostatic force; (2) buoyant forces; (3) hydrodynamic forces; (4) impulsive forces; (5) debris impact forces; (6) debris damming forces; (7) lift force; and (8) additional gravity load from water retained on the bridge floor. From the results of this study, it is shown that each of the tsunami forces acting on the crew-raba Lhoknga bridge at the minimum tsunami height variable, 11 meters, which is the initial height of the tsunami touching the bridge's superstructure are: 94.866 KN hydrodynamic force; 142,299 KN thrust; 133,810 KN debris impact force; 14,244 KN debris dam force, and 34,018 KN lift force. Meanwhile, the maximum tsunami height variable, 25 meters, is 24634.934 KN hydrodynamic force; 36952,400 KN thrust; 720,591 KN collision force; 3698,939 KN debris blocking force; and 986,519 KN lift styles. The results of the analysis using computational methods, by inputting the magnitude of the tsunami forces to the bridge model, it can be seen that the ability of the Krueng Raba, Lhoknga steel frame bridge to withstand the forces and loads caused by the tsunami only up to a height of 14 meters.

scholarly journals A Note on The Design of Seawall for Tsunami Disaster Mitigation

2021 ◽  
Vol 27 (1) ◽  
pp. 29-40
Author(s):  
Radianta Triatmadja ◽  
Warniyati Warniyati
Keyword(s):  
Laboratory Experiment ◽  
Drag Force ◽  
Impact Force ◽  
Hydrodynamic Force ◽  
Disaster Mitigation ◽  
Coastal Structures ◽  
Tsunami Disaster ◽  
Drag Forces ◽  
Hydrostatic Force ◽  
Tsunami Mitigation

Many coastal structures or structures in coastal areas were destroyed by a tsunami attack. Such destructions were due primarily to the fact that such structures were not designed to withstand a tsunami. Those which were designed to withstand tsunami force may also have been destroyed due to some damaging factors which were not included in the design. The damage of the coastal structures is one of the important factors that have caused casualties. Especially, when the destroyed structures were originally aimed to mitigate the area against tsunami, they may cause higher fatalities. Examples of such structures are sea walls in many parts of Japan which were destroyed by the 2011 tsunami. This paper discusses the important factors relevant to the damage of seawall as tsunami mitigation structure such as impact force due to tsunami front, hydrostatic force, and hydrodynamic force, debris force and scour due tsunami. The study was carried out based on literature about the damages of seawall as tsunami protection structures and laboratory experiment reports. The destructions to the structures were divided into three classifications namely instantaneous direct destruction due to impact and drag forces, slowly direct destruction due to drag force, and slowly indirect destruction due to scour. Finally, important aspects to be considered in the design of seawall as tsunamis protection were proposed.

Special Issue on the 2011 off the Pacific Coast of Tohoku Earthquake Tsunami

2013 ◽  
Vol 8 (4) ◽  
pp. 547-548
Author(s):  
Tomoyuki Takahashi ◽  
Nobuo Shuto
Keyword(s):  
Power Plants ◽  
Tohoku Earthquake ◽  
Disaster Prevention ◽  
Hazard Maps ◽  
Special Issue ◽  
Tsunami Height ◽  
Sanriku Coast ◽  
Tsunami Disaster ◽  
Run Up ◽  
2004 Tsunami

An unprecedented M9.0 earthquake occurring at 14:46 local time on March 11, 2011, off of northeast Japan’s Pacific Ocean generated a huge tsunami which had a run-up of over 40 m at the highest point and nearly 20,000 lives were lost. The tsunami demonstrated the need to drastically readdress current tsunami countermeasures. “Guidebook for Tsunami Preparedness in Local Hazard Mitigation Planning” published prior to the March 11 tsunami had already estimated, as one of the cases of tsunami assumptions, that the tsunami could be generated by the largest earthquake near off the Sanriku Coast predicted by the recent seismology. The seismotectonics had predicted that off the Sanriku Coast consisted of three independent blocks, which could conceivably cause an M8.6 earthquake at the largest. However, three blocks were not independent and they moved continuously to yield an earthquake of M9.0. The Guidebook had recommended a combination of three approaches for handling such a tsunami; Construction of defense structures, Tsunami-resilient town development, and Disaster prevention systems – defense structures were not expected to completely prevent every tsunami but only reduce its effect. Caissons forming part of Kamaishi Port’s tsunami breakwaters and registered in Guinness World Records, were overturned but reduced the tsunami height from 14 m outside the port to 8 m inside. Many coastal dikes were also destroyed, even though three surfaces – fore slope, top slope, and rear slope – had been protected using concrete and other means. Such phenomena pinpoint the importance of toe protection against erosion. Since 2004, tsunami inundation hazard maps have been distributed to communities in Japan as an aid to public education and as part of the country’s nationwide disaster prevention system. Unexpectedly, these maps had a negative effect in many places where residents living outside inundation areas mentioned on the hazard maps believed they were safe under all condition. Many did not in fact keep track of the actual tsunami rising in front of their very eyes and not evacuate, thus losing their lives. The tsunami hitting the coast of the Fukushima Prefecture had a run-up height almost double that designed in defense plans. The Fukushima No.1 Nuclear Power Plants of the Tokyo Electric Power Company (TEPCO) located on ground 4.8 m above sea level were immerged and a concurrent electric system failure led to total plant shutdown. The Fukushima nuclear disaster itself has become well known worldwide. The effects of the tsunami, however, are less so, despite damage such as fires, railroad destruction and drifting ships caused by the tsunami. With the nuclear incident overshadowing such effects, we are concerned that these results might be overlooked. To better prepare against potential future tsunami disasters, we must understand clearly what sort and how such diverse damage has been generated by the 2011 tsunami. This special issue focuses on the various types of tsunami-induced damages, emphasizing the valuable data and modeling obtained from field investigations in the tsunami-devastated areas. It will be more than worth publication if this special issue contributes in whatever way to furthering tsunami disaster research. Finally, we extend our sincere thanks to all of the contributors and reviewers involved with these articles. (written by Nobuo Shuto and Tomoyuki Takahashi)

scholarly journals Post-2004 Tsunami: Preparedness of Malaysian coastal communities

2018 ◽  
Vol 3 (9) ◽  
pp. 113
Author(s):  
Rustam Khairi Zahari ◽  
Raja Noriza Raja Ariffin ◽  
Zainora Asmawi ◽  
Aisyah Nadhrah Ibrahim
Keyword(s):  
Disaster Management ◽  
Publishing House ◽  
Coastal Communities ◽  
Indian Ocean Tsunami ◽  
Tsunami Disaster ◽  
International Publishing ◽  
The Indian Ocean ◽  
Tsunami Preparedness ◽  
2004 Tsunami ◽  
The Impact

The Indian Ocean tsunami of 26th December 2004 unleashed catastrophe in many nations including coastal communities located along the west-coast of Malaysian Peninsular.  The goal of this study is to explore the impact of the tsunami to the preparedness of the affected coastal communities.   Data was collected through questionnaire, interviews, documents analysis and field observations.  It was found that the 2004 tsunami disaster has left a significant mark on Malaysia's and the world's disaster management landscape but the tragedy has also heightened disaster awareness and steps must be taken to ensure vulnerable communities are well-equipped to face any eventualities. Keywords:  Tsunami; sustainable coastal communities; disaster management; vulnerability. eISSN 2514-7528 © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.

Development and Optimization of Mathematical Model of High Speed Planing Dynamics

2015 ◽  
Author(s):  
Prin Kanyoo ◽  
Dominic J. Taunton ◽  
James I. R. Blake
Keyword(s):  
Relative Velocity ◽  
High Speed ◽  
Lift Force ◽  
Hydrodynamic Pressure ◽  
Physical Nature ◽  
Ship Motions ◽  
Additional Contribution ◽  
Forward Speed ◽  
Planing Craft ◽  
Hydrostatic Force

The primary difference between a planing craft and a displacement ship is that the predominant force to support the conventional or displacement craft is hydrostatic force or buoyancy. While in the case of planing craft, the buoyancy cedes this role to hydrodynamic lift force caused by flow and pressure characteristics occurring when it is travelling at high forward speed. However, the magnitude of hydrostatic force is still significant that cannot be completely neglected. Due to the high forward speed and trim angle, the flow around and under the planing hull experiences change of momentum and leads to the appearance of lift force according to the 2ndlaw of Newton. In other words, there is a relative velocity between the craft hull and the wave orbital motion that causes hydrodynamic pressure generating hydrodynamic lift force act on the hull surface. Then, in case of behaviors in waves, an additional contribution of ship motions is necessary to be considered in the relative velocity, resulting in nonlinear characteristic of its physical nature.

Steady performance prediction of a heeled planing boat in calm water using asymmetric 2D+T model

2016 ◽  
Vol 231 (1) ◽  
pp. 234-257 ◽  
Author(s):  
Parviz Ghadimi ◽  
Sasan Tavakoli ◽  
Abbas Dashtimanesh ◽  
Rahim Zamanian
Keyword(s):  
Performance Prediction ◽  
Computational Algorithm ◽  
Hydrodynamic Force ◽  
Center Of Gravity ◽  
Drag Forces ◽  
Proposed Model ◽  
Hydrostatic Force ◽  
Calm Water ◽  
Pressure Area ◽  
Heeling Moment

This article presents a simple mathematical model for predicting the running attitude of warped planing boats fixed in a heel angle and free to trim and sinkage. The proposed model is based on asymmetric 2D+T theory utilizing a pressure equation which is previously introduced in the literature to compute the hydrodynamic force acting on a heeled planing hull. Integration of pressure distribution on the asymmetric wedge sections enables the suggested model to compute trim angle, center of gravity rise, resistance, and heeling moment acting on the heeled planing boat in calm water. The hydrostatic force in addition to two drag forces acting on the pressure area and spray area are also taken into account. Finally, a computational algorithm is introduced to find the running attitude of the heeled planing boats. The validity of the proposed model is examined by comparing the obtained running attitudes for two planing hulls series with zero heel angle and computed lift force and heeling moment of a heeled planing boat against available experimental data. Based on the comparisons, favorable accuracy is observed for both symmetrical and asymmetrical conditions. Moreover, it is shown that existence of a heel angle can lead to a decrease in trim angle and resistance, while it intensifies the center of gravity rise of planing boats. It is also observed that as the beam Froude number increases, the heeling moment of the heeled boat reduces.

scholarly journals Location Mapping And Tsunami Disaster Evacuation Pathway Using Dijkstra Algorithm In Kota Sigli District, Pidie District

2019 ◽  
Vol 6 (2) ◽  
pp. 748 ◽  
Author(s):  
Husna Maulida ◽  
Faisal Faisal ◽  
Teuku Alvisyahrin
Keyword(s):  
Secondary Data ◽  
Primary Data ◽  
Topographic Map ◽  
Dijkstra Algorithm ◽  
Contour Map ◽  
Tsunami Disaster ◽  
Vertical Evacuation ◽  
Paved Road ◽  
Location Mapping ◽  
2004 Tsunami

Sigli City Sub District is one of the Sub Districts affected by the 2004 tsunami. At that time, the community did not understand the danger of the tsunami and did not understand how to save themselves. The purpose of this study was to identify and to map out effective tsunami evacuation locations and routes in Sigli City Sub District using Dijkstra algorithm. Primary data (tsunami inundation) for this study were obtained from interviews with community representatives involving 32 people in 16 villages. Administrative map, topographic map, population density map, contour map and land use map (secondary data) were obtained from relevant institutions. The results of the study indicate that horizontal evacuation can be done through available paved road living the coastal area towads 4 recommended locations based on the physical feasibility of the land. For vertical evacuation, 24 buildings available in 7 villages can be recommended, on the condition that their structural feasibility and access standard are met.

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