日本沿岸域学会論文集
Online ISSN : 2758-3686
8 巻, 1 号
選択された号の論文の17件中1~17を表示しています
論文
  • 新宮 清志, 佐久田 昌昭
    1996 年 8 巻 1 号 p. 1-11
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    The concept of soft -settled -type offshore structure was proposed by one of the authors, and after that , the English name of this structure was named by the authors. The structure exerts much less weight on the seabed. This allows it to resist wave forces while being able to slide against seismic forces, with a magnitude greater than a certain level. The structure does this by adjusting the friction forces between the structure and the ground. Therefore, the soft -settled -type offshore structure has the following characteristics:

    1) We can avoid the consolidation settlement of the submarine ground by controlling the weight in water of the structure.

    2) We can expect the reduction of the dynamic responses of the structure when there are strong earthquakes.

    In the past, the dynamic behavior of the independent or moored type of the soft -settled -type offshore structure mainly with rectangular cross section were researched.

    In this paper, dynamic response analysis of a moored type structure with circular cross section subjected to seismic forces in the horizontal direction are presented. Further, experiments on a model of such a structure are presented , and the characteristics of the structure are clarified.

  • 鶴谷 広一, 野村 貴之
    1996 年 8 巻 1 号 p. 13-24
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    Wind speed and turbulence structures behind wind barrier are investigated experimentally. Three kinds of structures are tested, viz, trapezoidal dike, mesh screen, and cylindrical structures. Horizontal and vertical wind speeds are measured simultaneously with a 2 color laser -Doppler anemometry. Wind speeds near the bed behind the structures decrease nearly half of the original wind speed. The turblence, on the other hand, increases for the trapezoidal dike and the gust factor increases up to 2.5. The instantaneous velocity, therefore, is likely to exceed the original wind speed. For another structures, turbulence does not increase and the values of the gust factor remain the order of unity.

    From the experimental investigations, it is revealed that in the region behind the trapezoidal dike, despite decrease in the mean velocity, the turbulence increases and it is possible that the instantaneous velocity is likely to exceed the original wind speed.

  • 橋本 牧, 高橋 昭七, 井上 紘哉, 嶋田 淳一
    1996 年 8 巻 1 号 p. 25-38
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    As for about 3096 out of the total fishing ports in Japan, the fishing boats have the difficulty to stay in the mooring basin because of the strong wind under stormy weather. The Fisheries Agency has been studying the countermeasures against winds in the fishing ports.

    This paper presents the study on method of the field survey and analysis for forecasting the strong wind, based on the results of the field surveys at the three sites with various topographical conditions.

  • 萩原 秀樹, 鶴田 三郎, 高橋 洋二, 苦瀬 博仁
    1996 年 8 巻 1 号 p. 39-51
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    In this study, some policies concerning ship operations and port facilities to improve the safety of navigation in Tokyo Bay are proposed. These policies are:

    ① change of ship's route

    ② enlargement of tanker size

    ③ change of departure time

    ④ installation of pipeline

    ⑤ shift of tanker berth(including④)

    ⑥ composite policy (②十④十⑤)

    To evaluate the effect of each policy, a new marine traffic simulation method is developed. This simulation method represents the marine traffic flow by the network and the ships generated at the origin nodes proceed on the links of the network to the destination nodes. Subjective judgement value proposed by Hara is used as an index of the ship's collision risk. The effect of each policy is quantitatively investigated by calculating how many dangerous ships having high collision risk can be reduced by that policy . As a result, it is found that the composite policy is most effective to improve the safety of navigation . The enlargement of tanker size and the installation of pipeline are especially effective as a single policy. It is concluded that the developed marine traffic simulation method is very useful to find out the places where high collision risk exists and to examine the policies for improving the safety of navigation.

  • Mamoru KOARAI, Toshio NAKAYAMA
    1996 年 8 巻 1 号 p. 53-64
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    The East Off Chiba Prefecture Earthquake occurred on December 17, 1987, was the first earthquake hazard attacked Tokyo Metropolitan area, since the 1923 Kanto Earthquake . Liquefaction phenomena occurred on the wide area, such as Kujyukuri plain, Tone -River lowland and Tokyo -Bay coastal area, comparing with the magnitude of the earthquake (M=6.7).

    Authors investigated the liquefaction phenomena on Tokyo -Bay coastal reclamation area . As the reclaimed area have increased with high speed on the coast of Tokyo -Bay area, it is important for disaster prevention on coastal area to know the places where liquefaction phenomena occurred .

    We mainly analyzed boring log data and interpreted aerial photograph. Since this earthquake was on the boundary line of the liquefaction phenomena due to this earthquake, this phenomena concentrated on undesirable geological condition. As the result of the investigation, liquefaction phenomena occurred on the following geological conditions.

    1 Buried valley.

    2 Fairway before reclamation.

    3 Channel during reclamation work.

    Common characteristic of these geological conditions is the existance of newly deposited thick sediment covering the ditch topography.

  • 和野 信市, 寺中 啓一郎, 吉田 昌稔
    1996 年 8 巻 1 号 p. 65-76
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    Tokyo port is located in the innermost environs of Tokyo bay which is the enclosed water. Tokyo port's water front is a center of urban development, as well as a distribution base for the greater metropolitan area. At the same time, the area is utilized as a multipurpose recreation center where citizen of Tokyo can enjoy various seaside activities.

    In this area, the shoals still survive and many organisms of sea life are present. The characteristics of the shoal will be analyzed through comparison of bottom organisms which inhabit an intertidal zone (approximately 土0m or shallower), a shoal(apporoximately -lm to-4m), a channel (apporoximately -5m), and a deep bottom(apporoximately -8m to -26m).

    This paper aims to compare the shoals with other zones, and will find out the merit of the shoals.

  • 小池 信之, 森田 伸二, 鈴木 康之
    1996 年 8 巻 1 号 p. 77-89
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    The present state of each port is the result of people 's will. Through the scrutiny of the history of Nagoya Port, we present a comprehensive method of analyzing the creation and development process of the port, focusing on the human factors.

    First we classify data into six categories that contain human ones of "policy" and "implementation system" and then organize them in a flow chart that clarifies the interrelationship between items. This way of reviewing the past suggests new aspects to the history and will be useful in conceiving the future usage of the port.

  • 平井 信夫, 清水 智之
    1996 年 8 巻 1 号 p. 91-103
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    From long ago, Japanese harbors were located in inlets and back bays where wave conditions are quiet, and cities developed around these harbors. Japan, however, is a highly mountainous country, and in many areas steep slopes press right down to the coast. Thisgeology influenced the form of towns and cities. In port cities that developed along coasts bordered by steep slopes, narrow stepped roads connected the harbor with the surrounding community. This presented problems in terms of disaster eveacuation and countermeasures, as well as various restraints on the daily living environment. In addition, these harbors now suffer difficulties in that they lack sufficient backlot space for storing containers, which have become the mainstay of modern high- speed, high -volume tranportation systems. Some of these harbors thus now suffer from decline of trunk industries and loss of population. To revitalize these harbar cities, a balance must be struck between the port area and the surrounding community. This basic research was designed to clarify the characteristics of harboe cities built on steep slopes, and to suggest directions for revitalizing them. The results identified distinct differences between these and harbor cities with more flat land.

  • 岡 道也, 村上 俊明, 吉森 裕
    1996 年 8 巻 1 号 p. 105-118
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    Recently, there has been an increasing demand from people for better public access to the coastline. Designing an attractive coastline is to proceed not only with detailed design for coastal areas but also with overall planning that takes into account the current trends of land -use and infrastructural development in the city as a whole.

    The purpose of this study is to analyze the formative characteristics of urbanization in coastal areas. This analysis is essential to the development of the practical solutions required for better public access, particularly for access from urban areas to the coastal zone.

    The procedures used in this study are as follows: First,Fukuoka City and Kitakyushu City were selected as study areas. Second, examination of the current use of existing coastlines as well as research on the process of urbanization which led to the current situation were undertaken. Next, the characteristics of land -use in coastal areas were defined and categorized. Finally, in light of recent land -use trends, problems related to efficent public access and requirements for implementation were discussed.

  • 池田 良穂, 大塚 耕司, 萩野 修一
    1996 年 8 巻 1 号 p. 119-128
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    A sea transportation network using high -speed car ferries of over 35knots is proposed for Seto Inland Sea. Such ferries run as fast as the average speed of a car on highway, and can travel a shorter distance than the distance through the highway . Therefore, the required times between most of cities by the ferries are shorter than that for a car using highway. The result of an analysis of the commercial profit demonstrates that the sea transportation by the high -speed ferries can compete with other transportation networks using conventional ferries, highway, etc.

  • 池田 良穂, 大塚 耕司, 益田 太
    1996 年 8 巻 1 号 p. 129-138
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    A new container distribution system using a huge floating container terminal in Osaka Bay for normal and high speed RO/RO ships and feeder trailers is proposed to replace the present one using container trailers mainly. An economical analysis demonstrates that the new system is better than the present one. Accessments of emission of CO2 and NOx shows the proposed system is environmental friendly if the number of high speed RO/RO ships is limited.

  • 畔柳 昭雄, 沖田 寛
    1996 年 8 巻 1 号 p. 139-149
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    The objective of this study is to understand the evaluation of the pleasure boat users at the storage facilities by survey using questionnaire method.

    The results of this search are summarized as follows:

    1. The pleasure boat users tend to store their boats in the neighborhood from their house . And this is one of the causes for the increase of illegally moored vessels.

    2. All pleasure boat users put their concern on restriction of charge storage, accessibility and so on. And there is a difference in the storage facilities concerning safety controls, service and so on.

    3. To equip the storage facilities, it is important to combine characteristics such as function and type of pleasure boat.

  • 敷田 麻美
    1996 年 8 巻 1 号 p. 151-159
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    Hegurajima is located at 50km north of Noto peninsular in the middle of Japan. The island is famous for its unique feature as the best place for bird watching in Japan and receives more than 800 bird watchers in 1994 . However, only few attempts have so far been made to estimate the economic value of bird watching. The author intends to evaluate the consumer surplus generated by the bird watchers. The consumer surplus of the bird watching is obtained using the travel cost method. The result shows that the consumer surplus of the bird watching at the island is about 14.43 million yen per year. This could be an useful indication for the cost allocation of environmental conservation and future management for visitors to the island.

報告
  • 福屋 正嗣, 幡谷 純一, 長野 章
    1996 年 8 巻 1 号 p. 161-179
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    We have estimated Hokkaido's fishery and fishing village's indexs 20 years into the future.

    In addition to these indexes, We have conducted research on the histories of fishing villages along with the collection of questionnaries of fisher persons related to the fishing industry. Given these results, We have projected future prospects of the fishing industry and ports in Hokkaido. We have also estimated types of lifestyles and managements of households engaged in the fisheries industry 20 years from now.

  • 小谷 通泰, 岡山 正人, 中下 光治
    1996 年 8 巻 1 号 p. 181-191
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    Between Honshu and Shikoku Districts, Akasi Bridge will open in 1998, following the completion of N aruto Bridge and Seto Bridge, and expressway network has been developing rapidly in Shikoku District. These changes in transportation networks will affect the truck operators'route choice behaviours and their business environment.

    The purpose of this study is to show the influence of the completion of Akasi Bridge on truck trnasportation on the basis of the questionnaire survey to truck operators. Firstly, the outline of the questionnaire survey, which was carried out by the authors in December 1994, is explained. Secondly, the present situation on freight transportation routes by trucks between Hanshin and Shikoku Districts is made clear . Thirdly, the attitude to the use of new Akasi Bridge and the requirements to the ferry transportation in future are shown. Finally, the truck operators'recognition to the influence of Akasi Bridge on their business environment is analyzed.

  • 宮崎 隆昌, 本木 基美
    1996 年 8 巻 1 号 p. 193-202
    発行日: 1996年
    公開日: 2023/04/17
    ジャーナル フリー

    The main purpose of this study is to suggest a new perspective to the present situation of the coastal zone of metropolitan areas which has undergone a rapid environmental alteration according to various industrial interests.

    In recent years, the situation of most coastal areas in Japan seems to have hit a certain limit without a contructive view. For instance, there have appeared waterfront projects, renewal of the port system, developements of recreational resorts at fishing villeges, and so forth.

    These structual alterations, especially, by industrial purposes, ir.ideed have been serving certain interests. However, it has been a long time since various questions in terms of environmental breakdown in these areas were suggested. Inefficiency of industrial concepts as in the past has led the industrial use of many of these areas, substantially, to a collapse, along with the end of high-ratial economical groth in the last decades.

    The study therefore consists of analysis and evaluation of the industrial use of the coastal areas. The analysis and evaluation are fully developed in order to prepared for suggesting new values,simoultaneouly, activation of the values on the vast industrial areas which have left without constractive importance.

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