- 著者
- Shunroku YAMAMOTO Masahiko TOMORI
- 出版者
- Japan Society of Civil Engineers
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.1, no.1, pp.322-328, 2013 (Released:2013-11-20)
- 参考文献数
- 13
- 被引用文献数
- 19 24
During the 2011 off the Pacific coast of Tohoku Earthquake, the earthquake early warning system operated by East Japan Railway Company controlled the Shinkansen trains through information from its seismic stations before large shakings hit the line. By analyzing the event history of the system recorded in its monitoring PCs, it was confirmed that the system first detected the seismic motion at 14:46:38.9 (JST) based on the data of the Kinkazan seismic station located closest to the epicenter, and issued the first control signal to trains between Shiroishi-Zaoh station and Kitakami station of the Tohoku Shinkansen line at 14:47:02.9 through the excess of acceleration threshold of the Kinkazan seismic station. The signal was issued 12-22 seconds earlier than the time SI value exceeding 18 cm/s along the line, which is the required value to stop trains based on company rules. After issuing the first control signal, other seismic stations began issuing signals through the excess of acceleration threshold almost sequentially according to certain delays caused by wave propagation from the hypocenter. Eventually, 27 trains (19 of them were running) along the line were safely controlled. In this paper, after summarizing the configuration of the earthquake early warning system of East Japan Railway Company and the warning logics adopted for the system, the system performance during the 2011 off the Pacific coast of Tohoku Earthquake is evaluated and discussed in detail.
- 著者
- Yu NAKAI
- 出版者
- 公益社団法人 土木学会
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.1, no.1, pp.242-250, 2013 (Released:2013-09-20)
- 参考文献数
- 11
- 被引用文献数
- 3 7
This paper reports the drafting process and current outline of the reconstruction plan for Otsuchi Town, Kamihei County, Iwate Prefecture, which suffered devastating tsunami damage caused by the Great East Japan Earthquake.
- 著者
- Hiroyuki GOTO Yoshiya HATA Yasuko KUWATA Hidekazu YAMAMOTO Hitoshi MORIKAWA Shunichi KATAOKA
- 出版者
- 公益社団法人 土木学会
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.1, no.1, pp.329-342, 2013 (Released:2013-11-20)
- 参考文献数
- 94
- 被引用文献数
- 3 6
The 2011 off the Pacific coast of Tohoku earthquake brought severe damage caused not only by the tsunami but also by the ground motions. The present manuscript summarizes the source mechanism/process and the characteristics of ground motions around eastern Japan during the earthquake. For the last two years after the earthquake, many researchers have devoted their efforts to analyzing and discussing the source and ground motions. New findings from some recent works are also cited. We, furthermore, introduce characteristics of ground motions at some typical damaged sites, where no records of ground motions were obtained during the main shock, using time histories of after shocks.
- 著者
- Shin OSAKI
- 出版者
- Japan Society of Civil Engineers
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.5, no.1, pp.226-245, 2017 (Released:2017-05-20)
- 参考文献数
- 44
This study aims to define site selection characteristics of shrines affected by tsunamis in the coastal areas of the Sanriku region, to understand the differences between the locations of shrines that did or did not survive the disaster through field surveys and historical reviews. First, through the field survey, this research demonstrates that shrines in the area are generally located on ridge of mountains less likely to be affected by tsunamis and the destroyed shrines tend to be located near the low-lying coastline or on flatlands. Second, through the historical reviews, the characteristics of shrine locations have greatly changed since the middle of the 12th century. This research indicated that shrines were mostly positioned along the ridge line during the time of the ancient belief system and became more diverse during the medieval period from the mid-12th century onwards, when the culture of “kanjo,” the ceremonial transfer of a divided tutelary deity to a new location according to the enshrined deity's character, was introduced to the area. In addition to this general site selection characteristics, the experience from earlier tsunamis affects the re-selection of shrine sites. In conclusion, the site selection system for the shrines consists of global and local mechanisms. Finally, the author suggests the possibility of utilizing the shrine's site selection characteristics as a way to hand down the tsunami experience to the next generations.
- 著者
- Ryota NISHIGUCHI Shunsuke TAGATA Kentaro KAGEYAMA Norihiro IZUMI Masato SEKINE
- 出版者
- Japan Society of Civil Engineers
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.10, no.1, pp.430-442, 2022 (Released:2022-08-20)
- 参考文献数
- 15
This paper presents the inverse analysis of boundary conditions and parameters of river flow. The adjoint variable method is adopted for data assimilation for weather forecasting and is found to improve forecasting accuracy. The adjoint equation and sensitivity were derived for one-dimensional unsteady flow, a numerical simulation method was illustrated, and the applicability of the method to an actual river was verified. Data assimilation using multi-point water gauges successfully estimated discharge at any point and the accuracy changed with the number of water gauges. In the case of a river channel network, the data assimilation results also showed high accuracy. Furthermore, the forecasting simulation using the assimilation results as initial values showed highly accurate predicted water levels up to two hours in advance. The data assimilation method was then applied for channel shape optimization. In the optimization of the channel shape, considering two cases of riverbed excavation and channel widening where the river water level was below the levee height, the inverse analysis was successfully applied to determine the optimized channel shape via one-time simulation.
- 著者
- Yojiro IKEGAWA Takaomi TOBASE
- 出版者
- Japan Society of Civil Engineers
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.9, no.1, pp.276-283, 2021 (Released:2021-09-20)
- 参考文献数
- 25
- 被引用文献数
- 4
Japan aims to reduce its greenhouse gas emissions by 80% by 2050 as a countermeasure against global warming. As part of its policy, by 2030, the Japanese government plans to put into action carbon dioxide (CO2) capture and storage (CCS) initiatives. On the other hand, site surveys for deep saline aquifers (DSA) in Japan are underway. This paper shows the potential for CO2 storage using self-sealing of CO2 hydrate as a breakthrough to increase site options and the possible amounts of CO2 to be stored around Japan. In particular, the potential oceanic regions and the possible CO2 amounts are estimated.
- 著者
- Muneo HORI Sheng WANG Lalith WIJERATHNE Tsuyohi ICHIMURA
- 出版者
- Japan Society of Civil Engineers
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.6, no.1, pp.12-23, 2018 (Released:2018-01-20)
- 参考文献数
- 22
- 被引用文献数
- 1
This paper seeks to reformulate moving particle semi-implicit method (MPS) in order to provide a mathematical interpretation of the method. It is shown that gradient and Laplace operators are evaluated by using volume integral of the Taylor series expansion of a target function and that the form of the volume integral evaluation of the differential operators is similar to MPS, suggesting that the volume integral evaluation is a mathematical interpretation of MPS. Numerical experiments using one-dimensional setting indicate a possibility of improving the accuracy of computing the differential operators when the reformulated MPS is used. Remarks on directions towards improving the accuracy of MPS are made.
- 著者
- Nobutada YOKOUCHI Petr MATOUS Kazumasa OZAWA
- 出版者
- 公益社団法人 土木学会
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.5, no.1, pp.313-320, 2017 (Released:2017-08-20)
- 参考文献数
- 35
- 被引用文献数
- 1
Although the importance of understanding the diverse values of participants in global infrastructure projects has been increasingly recognized, research on methods to assess moral values in such contexts is still lacking. This article proposes a method for extracting context-specific moral values in three steps: (1) vignette development, (2) interviews, and (3) data analysis. The article illustrates how the method can be applied to understand the way project members make and rationalize their decisions when faced with moral trade-offs in the management of infrastructure projects.
- 著者
- Kiyoshi KOBAYASHI Masayuki EGUCHI Akira OI Kazuya AOKI Kiyoyuki KAITO
- 出版者
- 公益社団法人 土木学会
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.1, no.1, pp.551-568, 2013 (Released:2013-12-27)
- 参考文献数
- 20
- 被引用文献数
- 4
This study proposes a methodology to find the optimal inspection policy for road pavement with uncertain deterioration processes. Since the deterioration progresses are characterized by a lot of uncertainty, the pavement conditions cannot be deterministically evaluated unless the inspection or repair activities are carried out. The road administrators have to decide whether repair should be implemented based upon the results of inspection. In this paper, the value of the inspection is evaluated by using the real option theory, and the optimal inspection and repair model is formulated to investigate the optimal inspection frequencies and repair policy, which may minimize the expected life cycle costs. Finally, the validity of the methodology presented in the paper is investigated by a case study dealing with the expressway in the real world.
- 著者
- Shinya HANAOKA Yuichi INDO Terumitsu HIRATA Tomoyuki TODOROKI Taro ARATANI Teppei OSADA
- 出版者
- 公益社団法人 土木学会
- 雑誌
- Journal of JSCE (ISSN:21875103)
- 巻号頁・発行日
- vol.1, no.1, pp.286-297, 2013 (Released:2013-10-18)
- 参考文献数
- 2
- 被引用文献数
- 10
During the initial stage of a disaster, aircraft operate intensively and simultaneously use several airports as bases, given their mandate to promptly perform their duties. Previously, disaster management faced challenges such as insufficient airport apron space, shortage of aircraft fuel, and inadequate information sharing among various involved organizations. During the Great East Japan Earthquake, aircraft— pri- marily civilian and government helicopters—used the Iwate Hanamaki Airport, Yamagata Airport, and Fukushima Airport as bases immediately after the disaster struck. These aircraft performed tasks such as information gathering, emergency rescue, and personnel and goods transport. For this study, we interviewed personnel in the organizations involved in operating these aircraft and airports during the disaster. Further, we considered the operational realities of disaster response activities at each airport to identify the lessons learned and challenges met. We present our findings and detail the role of an airport as a disaster management facility and the challenges faced by an airport during a disaster.