*********** +++++++++++++++++++++ 121394B.ENG + Source: ONR Asia + *********** +++++++++++++++++++++ Contributory Categories: BIO, ENV Country: Japan From: Techno-Ocean '94 Proceedings Volumes International Symposium 26-29 October 1994 Kobe, Japan KEYWORDS: With each item +++++ Part XIII/XIII 7 Items Item 1 V. II, p. 805-810 Text in Japanese DEVELOPMENT OF EQUIPMENT FOR CARRYING ARTIFICIAL CONCRETE BLOCKS BY MEANS OF ENDLESS CHAIN Hisao KATO Masato NAKAMICHI Masaaki TAMURO Niigata Machinery Office, The 1st District Port Construction Bureau,Ministry of Transport 4-3778 Irihune-cho. Niigata.951,Japan Tosiro HINATA Shozo FUCHIYAMA Toa Corporation 5 Yonban-cho, Tiyoda-ku, Tokyo, 102, Japan KEYWORDS: Artifical concrete block,endless chain ABSTRACT Artifical concrete blocks instaled in the sea for wave dissipasion sometimes need to be carried or removed for the expansion or redevelopment of existing port fasilities. Tying up this type of block with a rope either by workers on the sea or by divers at the bottom is always a risky operation. And carrying out any operation which involves the worker or diver having to approach and rope those blocks provides less productivity. Under these circumstances,a more efficient type of equipment is developed both to carry or remove those blocks from the sea by means of an endless chain on a less expensive basis and to guarantee the lives of worker' lives. In addition the expected results are attained during sea trials of the experiment. +++++ Item 2 V. II, p. 811-816 Text in Japanese DEVELOPMENT OF ARMOUR BLOCK REMOVING EQUIPMENT (GRAB TYPE) Hisao KATO, Masato NAKAMICHI, Hasaaki TAMURO Niigata Machinery Office, The First District Port Construction Bureau, Ministry of Transport 4-3778, Irifune-cho, Niigata, 951, Japan Toshio KONDO Penta-Ocean Construction Co.,Ltd. 2-2-8, Koraku, Bunkyo-ku, Tokyo, 112, Japan Koichi NAKASHIO Hokuriku Branch, Penta-Ocean Construction Co.,Ltd. 2-5-1, Higashi-odori, Niigata, 950, Japan Yasuhiro MIYATA Seiko KONNO Nippon Tetrapod Co.,Ltd. 2-7-1, Nishi-shinjuku, Shinjuku-ku, 163-07, Japan Hirokazu SATO Hydraulic Laboratory, Nippon Tetrapod Co.,Ltd. 2-7, Higashi-nakanuki, Tsuchiura, 300, Japan ABSTRACT Recent expansion of port facilities towards offshore zones and reconstruction of existing facilities call for removal or replacement of armour blocks used in breakwaters or quay walls. As armour blocks are manually lifted with slings by divers and operators, the operation is quite dangerous and inefficient and requires improvement in safety and efficiency. Along the west coast of Niigata. for example, as many as 50,000 armour blocks must be removed to faciliate new reconstruction projects. Similar situation exsists throughout Japan. The Ministry of Transport has organized a committee of experts and specialists and launched survey/research work for the development of equipments capable of removing armour blocks safely and efficiency. The Committee has conducted an extensive and multi-faceted study and reacred the conclusion that a grab- type removing equipment is most promising. The Ministry and two companies conducted a joint study between 1991 and 1993 to deve.op a grab-type removing equipment, and report here the results of model tests, outline of the prototype, and results of field tests on the sea and the land. +++++ Item 3 V. II, p. 817-821 Text in Japanese DESIGN METHOD OF RIP RAP SCOUR PROTECTION WORKS FOR PIER IN STRAIT (PART 1) KAZUO ISHINO HIDEO OTANI Taisei Corporation 344-1 Nase cho Totu-ku Yokohama city KEYWORDS: Rip rap scour protection, Seepage flow, Pier in strait, Design method, Hydraulic model test, Field mmureffient ABSTRACT Rip-rap scour protection has been commonly used for piers. But the rmdiod of the design is redier errq)iricalIn order to establish the prwdcal and reasonable nvthod s of design, the mechanism of the seepage flow in the scour pro@on should be carefully examined. The seepage flow is measured both in a hydraulic model test andinafteldmeasurementatAkashiStWtBridge. An-ediodofdesignisproposed,basedupontheresultsof the hydraulic model test and the results of the field measurement REFERENCES 1) Posey, C.J : Tests of scour protection for bridge piers, Proc. ASCE, Journal of the Hydraulic Division, voL 100 HY12, pp. 1773-1783, 1974. 2) Breusers, H.N. C. et al: Local scour around cylindrical piers, J. of Hydrauric Research, VoL 15, No. 3, pp. 21 1 - 252, IAHR, 1977. 3) Woeman, A : Riprap prowdon without filter layer, Proc, ASCE, Journal of Hydraulic Engineering Vol. I 1 5, No. 12, pp. 1615 - 1630, 1989. 6). 7) Raud kivi : Scouring, A- A- Balkema, pp.91-94, 1991. 8) K.W.Pilarczyk : The Closure of Tidal Basins, Delft University Press, pp.467-489, 1984. 9) Paintal, A.S. : Conerpt of Critical Shear Stress in Loose Boundary Open Channels, Journal of Hydraulic Research, No. 1, pp.91-113, 1971. 10) Maynord, S.T. et al : Riprap Design. Proc. ASCE, Journal of Hydraulic Engineering, Vol.115, No.7, pp.937-949, 1989. 11) Maynord, S.T. : Flow Resistance of Riprap Proc. ASCE, Journal of Hydraulic Engineering, Vol.117, No.6, pp.687-696,1991. +++++ Item 4 V. II, p. 823-828 Text in Japanese A STUDY OF THE REINFORCING STEEL CORROSION AND CONCRETE SURFACE DEFORMATION USING AN ELECTROLYTIC CORROSION TEST Hiroshi HARADA Yasuhiro UMEMURA Departmet of Civil Engineering, College of Science and Technology Nihon University 1-8,Kanda-Surugadai,Chiyoda-ku, Tokyo, Japan,101 KEY WORDS: Electrolytic Corrosion, Deterioration, Direct Current, Reinforced Concrete ABSTRACT In recent years, coastal reinforced concrete structures have suffered from deterioration of their reinforcing steels due to high concentrations of salt in these areas, and much of the damage is now visible. Therefore, it is necessary to conduct appraisals of a structure's maximum support load and the extent to which the reinforcing steels have corroded and deteriorated when taking repair and reinforcement measures against salt damage. In experimentally examining the way in which a structure's maximum support load decreases, the electrolytic corrosion method is often used because it can quickly cause steel to corrode, it is highly reproducible, and it allows a great amount of data to be gathered. However, a problem with this testing method is that the relation tetween the direction of the electric flow into the concrete and the condition and quantity of steel corrosion is not clear. Therefore, this study supposes a model that assumes the chlorides invading the steel from the cover of concrete are unidirectional, just like the salt particles that enter the steel of a reinforced concrete structure under natural circumstances. This study, using an electrolytic corrosion test of uni- directional electrical currents, also experimentally examines the differences in the conditions and quantity of steel corrosion and the changes that occur between the stages of slight concrete deformation and the final appearance of cracks. ***** Item 5 V. II, p. 893-898 A STUDY ON EFFECT OF SHORE PROTECTION FACILITIES ON ECOLOGY Shigenobu TANAKA Yoshihisa IWASAKI Coastal Eng. Div. River Dept. P.W.R.I. Min. of Construction KEYWORDS: shore protection facilities, effect on ecology, changes of environment, prediction model ABSTRACT A model in this study is to help better understand the effects of facilities and predict changes in ecology after construction. Data files which contain information on representative kinds of creatures are collected. Individual reaction model and an ecological model with which one can estimate the direct and indirect effects of shore protection facilities are developed. +++++ Item 6 V. II, p. 899-904 Text in English ON A DEAD-WATER AGITATION APPROACH TO PURIFICATION OF A LAKE, ESTUARY, AND ENCLOSED BAY WATER Hironao Kasai*, Osamu Tsukamoto**, Takahisa Matsumoto**, and Katsutoshi Yoshinaga*** * Nagasaki R&D Center, Mitsubishi Heavy Industries, Ltd., 5-717-1 Fukahori-machi, Nagasaki 851-03 JAPAN ** Nagasaki Shipyard & Machinery Works, Mitsubishi Heavy Industries, Ltd., 1-1 Akunoura-machi, Nagasaki 850-91 JAPAN *** Marine Giken Co., Ltd., 22 Furu-machi, Nagasaki 850 JAPAN KEYWORDS: entrophic water, stationary anoxic bottom water mass, water pollution, agitation for mixing, regional water purifer system ABSTRACT In recent years. various kinds of eutrophic water problems are being reported, which may have been caused by excess amount of effluent loading and little exchange of regional water. Eutrophication, once reached, will invite accelerated biotic activities and that often results in a formation of anoxic bottom layer especially in swnmer. This will further invite anaerobic decomposition and generation of hydrogen sulfide, etc.; thus, the environment of the region will become polluted unsuitable for marine life and production with eventual destruction of the region. Formation of oxygen-deficient water mass. a typical symptom of entrophic water pollution, is typically found in a stationary mass of the bottom layer resulting from the topological and thermal stratifying nature of the regional water which are left unactivated as dead water. When a mass of water remains unactivated in this way, however, it will induce further serious ecological problems. In an attempt to prevent formation of anoxic water for purification of regional water, an approach was made to eliminate dead water layer by agitating for circulation and mixing. For that as an objective, a jet-flow type agitator system was devised. Model test was made and an encouraging result was obtained. For confirmation, a full-scale agitator was built and field experiment has been conducted in a fresh water reservoir having a pondage of ca 110,000 m^3. The results indicate that the agitation has been successfully performed resulting in a very remarkable rise in dissolved oxygen (DO) in the bottom poor-oxic layer as followed by an apparent fall in the release rate of phosphate and metallic matters from the sedijrnent. Specific features of the proposed device are pointed out as an exciter of fairly mild and eco-friendly circulating current. Further discussion is made for future prospect of its use. +++++ Item 7 V. II, p. 905-910 Text in Japanese A STUDY OF SEA-WATER IMPROVEMENT USING POLYMERIC MATERIAL MARINE TEXTILES & STRUCTURE (MTS) RESEARCH ASSOCIAATION Kohji HASHIMOTO TAISEI CORPORATION Kiyoo TANI MITSUBISHI RAYON CO.,LTD. Yasuo FUJISAWA OBAYASHI CORPORATION Ichiro HANDA TEIJIN LIMITED Hiroshi KAWANISHI TORAY INDUSTRIES,INC. Masaki OKAZAKI KURARAY CO.,LTD. Yasuo MASUDA UNMKA LTD. Masayoshi YANAGISAWA TOHO RAYON CO.,LTD. Makoto OTAGURO DAIWABOU CREATE CO.,LTD.. Ryo CHIKANO JAPAN CHEMICAL FIBRES ASSOCIATION KEYWORD: Polymeric material, Organicadhesion,S ea-water improvement ABSTRACT Creation of a habitat for various kinds of marine organism is key to the improvement of sea-water in a closed bay.Polymeric material(fiber),as a base of marine organism,is light in weight,easy to hande and has wide contact area. To investigate the attaching capability of marine organism on polymeric materials and removal efficiency of N-NH4 (ammonia nitrogen), we immesed 8 types of specimens in cifferent shapes, into sea-water tanks and Tokyo Bay. The three-dimentional net-like shape is found best in organism attachment and the cloth-like shape has the best removal rate of N-NH4 among other specimens. We also show an image of the expected structure of the sea-water improvement using polymeric material and the total plan of such a facility. +++++ END Part XIII/XIII ************** END MSG. B.ENG **************