Experimental investigation on the stability of bride girder against tsunami forces

Bridges are the most useful part in the transportation network. Any disruption of the bridge structures may hamper the whole transportation system. In the last recent tsunamis, numerous number of bridges were structurally damaged by the tsunami waves. Lack of proper provisions of tsunami forces in the design guidelines also contributes to the augmentations of the damage level. Therefore, proper evaluation of the tsunami forces on the bridge girder should be introduced in the design promptly. In this study, laboratory experiments were carried out to reveal the damage mechanism of the bridge girder by assessing the exerted tsunami forces. Both broken and unbroken waves were considered for the analysis. The results showed that measured forces were larger for broken waves than those of unbroken waves. Maximum force of the broken waves was 4.59 times as large as the hydrostatic pressure. Also, waves reached the peak value more rapidly for larger wave heights than those of smaller ones. Additionally, a girder that is placed at a higher position is much vulnerable to tsunami hazard.     

海啸与核安全

结合2004年12月26日上午在印度尼西亚苏门答腊岛附近海域发生的9级地震引发的海啸，介绍了海啸的诱发因素，阐述了海啸与核安全的关系，对中国可能遭受海啸影响的问题做了基本估计，提出了在核设施厂址选择中对海啸的工作思路。     

世界特大洪水

介绍了第四纪以来世界特大洪水的规模、成因，论述了特大气象洪水的时空分布规律．对洪水研究提出了4点建议。     

Posttraumatic growth among Norwegian children and adolescents exposed to the 2004 tsunami.

This study examined posttraumatic growth (PTG), positive change experienced as a result of the struggle with trauma, in children and adolescents exposed to a high-impact disaster, after which their experience of secondary adversity was minimal. The study also examined whether reduction in posttraumatic stress symptoms (PTSS) over time related to reports of PTG. There were 105 participants, age 6 to 17 years, who were directly exposed to the 2004 tsunami in Southeast Asia. They were interviewed 10 and 30 months after the disaster—PTSS was assessed at both time points, and PTG was assessed at 30 months. The individual's subjective reactions to the event and concurrent PTSS (30-months post-tsunami) were independently and positively related to PTG, whereas the decrease in PTSS was not related to growth. Children and youth in this study reported lower absolute levels of PTG than those in other studies. Taken in sum, findings suggest that secondary adversities may influence posttraumatic reactions and ongoing distress, which are hypothesized to play a key role in the development of PTG. In the absence of such secondary stressors, continued distress in the form of PTSS may serve to catalyze the growth process. Implications for clinical practice are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Conceptual basics and tools to assess the multi hazard vulnerability of existing buildings

The European Macroseismic Scale 1998 – (EMS 98) is an instrument for the natural hazard of earthquakes, which allows the explanation of observed differences in the behaviour of the prevailing construction types by introducing and implementing vulnerability classes. The EMS 98 enables also the identification of purely empirically justified ranges of scatter. The basic methodology is also applicable to other natural hazards such as flood, tsunami and wind. This permits the development of a unified methodology for the consideration of building vulnerability in the sense of a multi‐hazard approach. For the first time, a vulnerability‐oriented instrument is available to evaluate a building stock for different natural hazards according to criteria that have been standardised in terms of engineering. The multi‐hazard vulnerability with its possible scatters is examined and visualized on real building inventories. With the concept of ”LEGOisation“ the existing buildings, a novel approach is presented to allow the sub‐structuring of buildings into storeys (including roof, basement and floors) to further development of the classification towards specific damage characteristics and local vulnerability. A still to be developed ”Conceptual Simulation Tool“ is described as an outlook. This uses the tools and methods developed to simulate damage and losses as a result of various natural hazards and their sequences.     

沿海桥梁地震海啸作用机理与对策试验研究

地震海啸灾害对沿海工程结构的破坏是巨大的。我国沿海大桥建设近些年得到空前发展,且有受到地震海啸影响的危险,故如何保障沿海大桥在地震海啸作用下的安全是一个重要的课题。该文通过地震海啸（孤立波模拟）作用下桥梁模型试验研究了海啸对桥梁的作用机理及减轻海啸作用对策。首先,通过不同孤立波波高和水深试验研究了地震海啸对桥梁的作用效应与规律;进而提出在桥梁的桥面板上开孔的措施减轻海啸作用对策,通过对比试验研究桥面板开孔措施对减轻海啸作用下的桥梁动力反应以及桥面板受到的竖向作用的有效性。     

Correlation analysis of a reinforced-concrete building under tsunami load pattern and effect of masonry infill walls on tsunami load resistance

The 26 December 2004 Indian Ocean tsunami caused damage to many buildings and killed a lot of people in several Indian Ocean countries, including Thailand. Several reinforced-concrete (RC) buildings in Southern Thailand that were gravity-load-designed buildings suffered damage due to the tsunami. To understand the behaviour of RC buildings under tsunami loads, the one-story building, which was the former office of the Thai Meteorological Department located in Phang-Nga province, was tested under tsunami load patterns. In this research, the RC building is modelled for three-dimensional non-linear static pushover analysis. In the building model, masonry infill walls are idealised as diagonal struts by using uniaxial non-linear springs, and plastic hinges are modelled by non-linear fibre elements. The results of the building model agree well with test results. The effect of masonry infill walls is investigated by considering various wall arrangement patterns. The building with masonry infill walls can resist the lateral load two times higher than the resistance of the building without masonry infill wall. The masonry infill walls with the appropriate arrangement can significantly improve the load-resisting capacity of the building under tsunami loads.     

The impact of "training the trainers" course for helping tsunami-survivor children on Sri Lankan disaster volunteer workers.

The authors evaluated the impact of a "training the trainers" course for helping Sri Lankan tsunami-survivor children on education and mental health disaster volunteers. Sixty-two disaster volunteers were randomly assigned to either a school-based (ERASE Stress) "training the trainers" course or to an alternative "befriending" program that served as a control group. Participants in the ERASE Stress course significantly improved their perception of self-efficacy as tsunami survivors' helpers (Disaster-Helper Self-Efficacy Scale), self-mastery (Mastery scale), and optimism about their personal future (item from the Children's Future Orientation Scale). In addition, the perceived ability to use cognitive coping strategies (Cognitive Emotion Regulation Questionnaire) such as refocusing on planning, positive reappraisal, and putting the trauma into perspective was enhanced. The ERASE Stress course may be an effective method for strengthening local community capacity to deal with trauma survivors in developing countries. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of bridge deck on tsunami loading on inland bridge piers

The customary method of computing the hydrodynamic force on a pier of a bridge is based on the model tests of stand-alone piers. This implicitly ignores the influence of the deck on the flow pattern around the piers. The hydrodynamic force exerted on the piers by a solitary-like wave generated in a hydraulic wave flume is investigated using a complete pier-deck model, which includes both the pier and deck in the actual proportion. The experimental results reveal that the hydrodynamic force on the piers is influenced by the presence of the deck. For the complete bridge configuration studied, the actual force component which results from the hydrodynamic pressure acting on the piers only could be increased by as much as 50% over that for the case of stand-alone piers. This is due to the influence of the deck in obstructing the free splashing and topping over of the wave upon striking the piers, resulting in accumulation of fluid in front of the piers, and hence increasing the pressure on them. Thus, the hydrodynamic force computed based on experiments on stand-alone piers could be non-conservative for design of piers.