SEISAN KENKYU
Online ISSN : 1881-2058
Print ISSN : 0037-105X
ISSN-L : 0037-105X
Volume 65 , Issue 4
Showing 1-35 articles out of 35 articles from the selected issue
Introduction to Special Section
Research Review
  • Haruo SAWADA
    2013 Volume 65 Issue 4 Pages 353-358
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    While aerial photos were useful in identifying damage levels of the tsunami by visual interpretation, the interpretation of the whole damaged area required plenty of time and manpower. Meanwhile, high-resolution satellite images were used in identifying the damages, with the comparison of pre- and post- quake images enabling us to identify the reality of the destruction. In such ways, remote sensing data hold potential in the field of large earthquake disaster management. However, their products were seldom used in tsunami damaged sites. These real situations have shown us the importance of appropriate preparation for making remote sensing data useful to a large disaster.
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Research Flash
  • Muneyoshi NUMADA, Ayaka HARA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 359-363
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    After the 2011 Tohoku Earthquake in Japan, we observed a concentration of news coverage on the damage and disaster response activities in specific municipalities and a high emphasis was given on the nuclear power plant accident. The concentrated news coverage induced the concentration of aid activities such as distribution of relief supplies and donations to the specific areas. This problem has repeatedly happened in the past disasters as well. The purpose of this research is to conduct a quantitative analysis of the municipalities that were repeatedly covered by the TV news and newspaper reports. The results shows that there is a string relationship between the reported municipalities with frequent and the amount of the relief money. But the low relationship between mass media reports and the number of volunteers is shown.
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  • Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 365-371
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    This study aims to achieve an effective disaster response system immediately just after the earthquake. In this paper, we analyzed the initial response of Yabuki town immediately after the Great East Japan Earthquake. As a result, we found that many officials had worked for food supply, water supply and its sorting and transport which are some of the disaster responses everyone can operate.
    To operate the effective initial disaster response, around 130 Yabuki town officials should be located or assigned correctly by understanding the initial disaster response kinds and definition of its characteristics. In this paper, we categorize the initial disaster responses into 4 levels. To build an effective disaster management plan, each disaster responses should be categorized and visualized its frameworks.
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  • Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 373-377
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    The purpose of this study is to analyze the time coverage of prime time immediately after the Great East Japan Earthquake. As a result, normal programs such as entertainment, sports etc. started to show from the 13th March 2011. In addition, the special program of then, it was found that all special programs about the disaster were explained by Mr. Akira Ikegami.
    It is important that the needs of the viewer, the viewpoint of management, the element of the programming contents on prime time are taken into account during large scale disaster, and if necessary the programs can be shifted to the normal contents.
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  • Japan Earthquake.
    Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 379-385
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Social media such as Twitter, Facebook etc. in addition to the existing media of television and newspaper provide a variety of information during the Great East Japan Earthquake. In this study, Twitter on Kesennuma, local newspapers, global newspaper and TV are analyzed and compared to clarify its characteristics.
    As a result, all media used the "evacuation" with the highest importance, all media but excepting Twitter used "debris", "landed of fish" and "temporary housing" with largest importance.
    In addition, "Caution" and "Worry" are used by Twitter to ask directly to the residents. Local newspaper reports life information such as store openings and its time. Global newspaper reports the list of the people who are killed by this hazard. The TV reports economical activities, such as "Company", “Business”.
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  • Akiyuki KAWASAKI, Michael HENRY, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 387-394
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    After the Great East Japan Earthquake, many overseas governments issued advisories to their citizens in Japan to relocate to the western Japan or leave entirely. Through a questionnaire survey at the time of the disaster, the relationship between the advisories issues by overseas governments and the behavior of foreigners in Japan was investigated in order to examine the differences among people who did not follow the recommendations of their government. Three sample groups were created based on the advisory actions of overseas governments, and the characteristics of post-disaster action and disaster information collection were analyzed.
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  • Shinya KONDO, Yusuke MESHITSUKA, Nodoka UJITA
    2013 Volume 65 Issue 4 Pages 395-399
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In this paper, the design and management of practice to learn lessons of the volunteer firefighters in the 2011 Tohoku Earthquake and Tsunami are discussed from the points of the development of practice to learn the ability and the improvement in PDCA cycle. The aim of this practice was to recognize "the safety of team members in the volunteer firefighters activities including 'evacuation'" as the lesson of 2011 Tohoku Earthquake and Tsunami. And this practice was designed according to the practice design flow for learning the ability. This practice was conducted in 15 prefectures, and managed in PDCA cycle.
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  • Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 401-405
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    This paper analyzes the disaster response of Yabuki town during the Great East Japan Earthquake for the reconstruction of the disaster prevention system in this town. The reconstruction points are (1) the unification of various manuals or plans such as disaster prevention plan, initial disaster response manual and manual of disaster prevention shelter. (2) The reconstruction of disaster response headquarters system, ensure of the necessary supplies,ensure of the necessary equipment (emergency infrastructure support, etc.), management important facilities (water supply facilities, means of communication, support equipment for electric power failure), shelter secure facility (earthquake resistance and enhancement of, the number of construction, standards, making rules, etc.).
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  • Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 407-415
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    This study aims to develop "Strategy system for Disaster planning” for government stakeholders to design and implement an effective disaster prevention strategy. In this paper, we have analyzed as the first step, in the case Yabuki town, how disaster-related budget are used.
    As a result, in the parts of risk management, the budget is mainly used for implementing the emergency effective response. The parts for the directly reducing the damages are small.
    On the other hand, it is difficult to analyze the effectiveness and necessity of each countermeasures by only the use of the budget shown in this paper.
    To achieve our purpose, we need to develop the ROI (Return On Investment) model in the disaster management field.
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  • Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 417-423
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    The purpose of this study is to develop the life support system (ITONAMI). In daily life or before disaster, this system can be used for planning the proactive response of services of nursing care and the countermeasures based on the regional risk assessment. In disaster phase,this system can be used for supporting the effective disaster response and for the integrated disaster management about the damaged people.
    This paper shows some analysis results about the natural disaster victim’s relief focusing on information sharing. On the other hand, some examples to use this system regarding the watching the elderly and the assessment of regional risk in the daily life are shown.
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  • Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 425-431
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In this paper, we analyze the support system among municipalities during the Great East Japan Earthquake for the effective support system during large scale disasters. As for the case study, the relationship between Yabuki town in Fukushima prefecture and Mitaka city in Tokyo is analyzed from the viewpoints of both supporting and the supported side. The obtained results can be applied to the revise of disaster management plans for the next big disaster with effective and efficient response.
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  • Muneyoshi NUMADA, Kanako TOGO, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 433-439
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    To improve total management disaster capacity, it is extremely important to assume and imagine the next action one should take. In order to achieve this ability, we must perform imagination-training in preparation for disasters.
    We carried out the disaster imagination workshop with some educational facilities for the purpose of improving disaster imagination capacity.
    The purpose of this research is to build the environment to be able to manage classes for improve the disaster imagination capacity by school teachers without disaster management experts. This paper shows the results obtained from the Higashijujo elementary school and Matsukawa junior high school. The both results shows that school teachers can manage the class for improve the disaster imagination capacity without disaster management experts.
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  • -Case study of the building of orphanage in Indonesia-
    Muneyoshi NUMADA, Masayuki WATANABE, Masato KURODA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 441-446
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In this study, we introduced the case of applying the method of PPBM to the dormitory building of an orphanage in Banda Aceh city. The seismic retrofit seminar by PPBM method can provide the lessons of the retrofitting techniques and the construction trainings of PPBM. Through the this construction projects, PPBM method was able to show that a local material and local people are available without a problem, and that it is a technology that is acceptable lifestyle on the local area.
    Furthermore, we found and improve the several construction process during this application,this technique can be used in the wide area of the world.
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  • Yuki MURAKAMI, Muneyoshi NUMADA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 447-451
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    To prevent the stone wall structure from collapsing by an earthquake, it is indispensable to grasp the anti-seismic performance and enforce the wall by retrofitting if necessary. In this study, the authors has conducted an analysis of seismic response of historic stone wall structure and examined the retrofitting method based on the Two-dimensional Extended Distinct Element Method.
    In this study, the anchor-reinforcement method was selected as an anti-seismic reinforcement. By comparing the movement of the wall with or without anchor reinforcement and recognizing the pattern by various applications, the study indicated the necessity of anti-seismic reinforcement as well as the tendency of response behavioral change and examined the validity of anchor reinforcement.
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  • Makoto FUJIU, Miho OHARA, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 453-457
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In Japan, several big earthquakes are expected to occur in the near future. A lot of structural damages due to these earthquakes will cause enormous needs for building damage assessment. However, current number of human recourses who are trained with the procedure of building damage assessment is not enough. It is necessary to increase the number of investigators before a next event. In this research, authors develop application for recording pictures of damaged houses for remote building damage assessment system.
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  • Hiroshi SUGATA, Takaaki KATO
    2013 Volume 65 Issue 4 Pages 459-463
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Multi-agency collaboration and public-private partnership has been referred to be essential in Japanese Cabinet's crime prevention scheme since 2003. Municipal fire headquarters have been strongly recommended to make arson prevention plans in collaboration with local communities. However, there has been no attempts to compare arson risks among municipalities nationwide. This paper reports current research situations on arson prevention in Japan. Then it presents two maps with results of cluster analysis with arsons as an exploratory analysis. The result strongly suggested necessity in further investigation in temporal aspects between the incidents.
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  • Hitoshi NAKAMURA, Haruyuki TORIYAMA, Yuto SHIOZAKI, Takaaki KATO
    2013 Volume 65 Issue 4 Pages 465-468
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In response to the new policy directive on flood control measures adopted by the European Union in 2007, European countries have developed flood maps. As a preliminary study, the purpose of this paper is to examine overall situations of the making and use of flood maps in European countries, and to examine the relationship between flood maps and insurance system by the literature survey mainly. In Austria in particular, the summary of a project (HORA project) carrying out the making and publication of the flood map in the partnership of the government and the insurance association is introduced.
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  • Shinya KONDO, Yuki SADAIKE
    2013 Volume 65 Issue 4 Pages 469-472
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Disaster Reduction and Human Renovation Institution (DRI) developed Simulation Exercise of Emergency Response Headquarter Management by Objectives (SEMO), and provides the special training programs based on SEMO for the officer of municipalities. Atsuma town, Hokkaido,which is a small-scale municipality, planed and conducted the training programs based on SEMO for officers of Emergency Operation Center. In this paper, the authors introduce this case from the perspectives of the design and the framework.
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  • Tetsuya ISHIKAWA, Shinya KONDO, Akiyuki KAWASAKI, Miho OHARA, Kimiro M ...
    2013 Volume 65 Issue 4 Pages 473-479
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In this study, situation and agendas of disaster information dissemination at Totsukawa village on the time of Typhoon Talas disaster were cleared. At Totsukawa village, people whose childhood home was Totsukawa village managed Twitter account to support village. The authors analyzed the data of this account from information transmission route and content classification,identified the wide diffusion of content classification, and quantified the wide diffusion of disaster information in chronological order. Then the authors proposed the possibility of effective use of social media considering other disaster information dissemination system.
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  • Preliminary analysis on the Characteristics of the Pasak River flood, an important tributary of the Chao Phraya River
    Daisuke KOMORI, Akiyuki KAWASAKI, Atsuro MORITA
    2013 Volume 65 Issue 4 Pages 481-485
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    The Chao Phraya River watershed has experienced many floods in the past. However, floods have not occurred frequently in Bangkok because most of the excess water is stored upstream in floodplains of the Chao Phraya River lower watershed. In the lower watershed, flooding is historically controlled by expanding the flood area to decrease the floodwater level. Therefore,to understand better countermeasures for preventing future major flood damage in the lower watershed, this paper preliminary investigates the Characteristics of the Pasak River flood, an important tributary of the Chao Phraya River.
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  • Preliminary survey on disaster management system in local level
    Akiyuki KAWASAKI, Daisuke KOMORI, Atsuro MORITA
    2013 Volume 65 Issue 4 Pages 487-489
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Local government and municipality system in Thailand consists of a bit complicated structure in 2 lines. Thus, it is difficult to understand the role of disaster response by each organization and the arrangement of data sharing and collaboration. We conducted interviews to local governments and municipalities in the lower Chaophraya River basin and the Northeastern Thailand. Based on the information obtained through limited numbers of interviews, we tried to partially summarize the role of disaster response and it’s actual condition in local government and municipality in Thailand.
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  • Preliminary analysis of the changes in Communities and the Irrigation System
    Atsuro MORITA, Daisuke KOMORI, Akiyuki KAWASAKI
    2013 Volume 65 Issue 4 Pages 491-496
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    This paper aims to outline the historical development of the river-society relationship in the lower Chao Phraya River basin. The basin development in the first half of the 20th century remade the river into a huge irrigation system with often-conflicting functions, e.g. water delivery in rainy seasons, selective dry season irrigation and flood mitigation by diverting water into designated area. These functions are intertwined in the historical formation of the irrigation system. The conflict among these divergent functions that has recently become visible due to the agricultural change and industrialization in the 1990s poses significant challenge for water management.
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  • Michael HENRY, Akiyuki KAWASAKI, Kimiro MEGURO
    2013 Volume 65 Issue 4 Pages 497-500
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    During the 2011 Thai flood, people searched for information regarding the disaster to better understand the situation and make decisions or preparations regarding whether to evacuate their homes or businesses. However, many people experienced information-related difficulties such as incorrect or conflicting reports, false rumors, congestion in networks such as hotlines, and so forth. In order to improve information dissemination in the future, a survey was conducted to understand how people collected their disaster information. This paper analyzes the results from the perspective of income level in order to propose effective information dissemination considering the difference in quality of living-related factors.
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  • Survey at Bara Bania Village in Manikgonj District
    Tomoko MATSUSHITA, Takanori SAWARA, Akiyuki KAWASAKI, Miho OHARA, Shin ...
    2013 Volume 65 Issue 4 Pages 501-508
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Bangladesh is highly prone to disasters such as flood and cyclone and there is a great interest for promoting disaster prevention measures using ICT infrastructure. The objective of this research is to conduct a basic research and analysis in order to apply the high-tech measures and findings already developed in Japan in the field of disaster information dissemination system against natural disasters to go with the local condition and the needs in Bangladesh.  In this paper, the authors introduce a site survey and interviews conducted in a rural village where a flood disaster information system project was implemented.
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  • Dang Anh NGUYET, Akiyuki KAWASAKI
    2013 Volume 65 Issue 4 Pages 509-515
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    This paper summarized the current and new trend in land-use change modeling, which have been developed for a couple of decades and have been increasingly attracted the attention of scientists all over the world. First, the rationale for the essential of land-use modeling was discussed. Land-use modeling has been developed in order to provide information for decision makers. However, these days, the technology bring new trend for land-use modelling process which comprise the participation the public community. Second chapter gave the reasons why categorizing of land-use change projection is difficult. There are many methodology approaches for land-use model. However, they overlapped in concept and methodology. Thus, the third chapter focused on current and potential approach of land-use change model. There are eight main methodology including: Markov chains; economic based; geographic based; Statistical Analysis; cellular automata (CA); geographic based, neural network analysis; agent-based and integrated analysis. Our review aims at the compactness, conciseness and synthesis.
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  • Yoshito SAWADA, Kazuo OKI, Takahiro ENDO, Haruo SAWADA
    2013 Volume 65 Issue 4 Pages 517-527
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In the present study, we automatically estimated a water spectrum in the MODIS images using the techniques developed by Sawada et al., and in an effort to construct a monitoring system for assessing flooding over a wide area, we attempted to assess the flood zone created by the flood that occurred from August to December 2011. Specifically, we calculated the beginning dates of flooding and flooding period in the Chao Phraya River Basin using the flooded area estimated from 10-day composite images using MODIS data and then estimated the flooded area attributed to the Chao Phraya River.
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  • Hirotoshi KISHI, Wataru NAKANISHI
    2013 Volume 65 Issue 4 Pages 529-532
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    This study aims to understand damaged area spatiotemporally by tweet data with location information as a case study of the Great East Japan Earthquake. Firstly, we make a list of tweet data with location information in Tohoku area from March 11 to March 18, 2011, from raw data of tweets in Japanese. In this process, bot accounts including seismic intensity information and "google person under" are excluded because they don't represent actual local conditions. Secondly, considering each tweet on the list as a expression of human activity of an area where tweet is made, we spatially extrapolate the tweets using Kernel density estimation approach and draw a "tweet-density distribution map." Then we try to understand the place and condition of damaged area is by this map, as well as comparison with other information such as DMSP night time map which is regarded as an indicator of ordinary human activities. As a result, we show the possibility of tweet data with location data to estimate heavily damaged area spatially and temporally. In addition, future works for further utilization of this map e.g. a review of useful comparison data for interpretation of proposed map are listed.
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  • Yoshiyuki TAKANO, Rieko KOJIMA, Kohei NAGAI
    2013 Volume 65 Issue 4 Pages 533-537
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    High Performance Fiber Reinforced Cementitious Composites (HPFRCC) shows superior tensile ductility, however its shear resistance property at crack surface shows lower performance. It was found to solve this problem that coarse aggregate improves load-carrying resistance for shear. Also, when this material is used as structural element, it is essential to evaluate both wide range of strain distribution and local scale crack behavior appropriately. In this research,image data analysis was adopted to investigate into these two features at the same time in shear beam tests. Through beam tests, the efficiency of course aggregate in terms of contribution for shear performance was observed. Also, problems of image data analysis are pointed out.
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  • Reiko KUWANO, Renuka HEWAGE INDIKETIYA SAMANTHI
    2013 Volume 65 Issue 4 Pages 539-543
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Internal erosion of the soil usually accompanies loosened soil around it. The degree and area of the loosening are dependent on the type of soil. In uniform sand, soil around the internal cavity expands and a lot of voids develop in the loosened area. On the other hand, for sand with fines, fine particles escape between coarse grains. In this study, loosening in the uniform sand was simulated and the mechanical properties of loosened sand were evaluated by triaxial testing. X-ray CT scanner was also used to estimate the extent of loosened area and to calculate the stiffness of loosened sand.
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  • Tsubasa SASAKI, Reiko KUWANO
    2013 Volume 65 Issue 4 Pages 545-547
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    In this study, microbially induced carbonate precipitation (MICP) was implemented on specimens made of Edosaki sand whose fine content is around 20%, in order to seek possibilities of MICP in the soil containing fine. The result showed that precipitation of calcium carbonate was concentrated around the injection point possibly due to Edosaki sand’s low permeability which might have caused bacteria and reagents trapped around the region. Although the permeability of the specimens leveled out during the treatment, it dropped significantly after the termination of the treatment which was followed by circulation of distilled water. Precipitation efficiency varied approximately from 40% to 60%. Further research needs to be performed to enable uniformly distributed and efficient MICP in the soil with fine.(120 words)
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  • Mari SATO, Reiko KUWANO
    2013 Volume 65 Issue 4 Pages 549-552
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Internal erosion causes various ground disaster such as cave-in accident, slope failure and etc., which is supposed to happen due to water penetration under the ground with severe rainfall. Especially in well-graded material, initially finer particles flow out and this flow makes drained water turbid, which has been considered as a warning of the ground failure. However, relationship between turbidity of drained water and internal erosion is not very clear. In this research, characteristics of internal erosion were evaluated from turbidity of drained soil by one dimensional column test. The test was conducted under various water penetration conditions simulating practical situations.
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  • Reiko KUWANO, Shinpei TAIRA, Jiro KUWANO, Mari SATO
    2013 Volume 65 Issue 4 Pages 553-556
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Significant number of subsurface cavities was found in the liquefied ground after the Great East Japan earthquake.In this study, a series of model tests is conducted in order to understand the mechanism of underground cavity formation when liquefaction occurs. According to the results of field investigation in Urayasu-city, Shinkiba-area, and Narashino-city, cavities tended to form near man-holes and joints in pavement. Size/shape of the cavities are larger and thinner compared to those of cavities observed in the non-liquefied ground. Liquefaction and sand boiling was simulated in the model test. Sand grains initially moved horizontally and then vertically, causing disturbance and loosening in the ground. Gaps and voids near the ground surface were eventually generated at the location of the boiled sand.
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  • Hiroshi YOKOTA, Katsufumi HASHIMOTO, Ryosuke SASAKI
    2013 Volume 65 Issue 4 Pages 557-561
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    When water penetrates into the cement hardened body of concrete structures under saturated conditions, the hydration products dissolve into pore solution and Ca ion leaches out from the hardened body. The Ca leaching makes permeability of the cement hardened body low. In radioactive waste processing structures, for example, long-term durability against the Ca leaching is fully investigated. In this study, an immersion experiment and an electrical accelerating experiment have been performed to evaluate the stability of cement hardened body. The phase change of hydration products is discussed with the results of XRD and TG-DTA analyses.
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  • Hiroshi YOKOTA, Shuhei KOMATSU, Koichi FURUYA, Katsufumi HASHIMOTO
    2013 Volume 65 Issue 4 Pages 563-567
    Published: July 01, 2013
    Released: December 24, 2013
    JOURNAL FREE ACCESS
    Lots of inspection work is needed for big, long structures such as coast levee and sea wall. To examine the possibilities to simplify the inspection, the number and the widths of cracks and the sizes of un-reinforced concrete parapets have been measured in the field investigation and extreme value statistics have been applied. It was confirmed that the distribution of maximum crack widths follows the Gumbel distribution. It was concluded that the maximum crack width can be predicted when only 1/5 to 1/4 area of the entire span of parapet are surveyed.
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