Danish Hydraulics - 1981 no.1

DANSK HYDRAULISK INSTITUT BIBUOTEKET

dhi Contents:

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Introductory Letter f Riser Model Tests Test Facility for Moored Offshore Structures exposed to Waves and Currents Environmental Design Aspects of Marine Pipelines for Danish North Sea Service Simulations of Pipe-Laying Operations - a Dynamic Seapipe System Scour around Platform Legs Rubble Mound Slopes as Protection against Ship Impact New Developments Short News

Front Cover: Hydraulic model testing of scour around the legs of a jack-up platform, (see page 14).

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Danish Hydraulics is a journal of the Danish Hydraulic Institute. It is distributed free of charge to research institutes, public authorities, international organisations and private companies. For further information please contact: The Editor, Danish Hydraulics, Agern Alle 5, DK-2970 Horsholm, Denmark, Phone: 45 2 - 86 80 33, Telex: 37 402 dhicph

Dear Reader, This is the first issue of "Danish Hydraulics", a publication intended to appear twice yearly with the purpose of keeping in touch with colleagues and friends of OHi throughout the world. Current publications from sister institutes and laboratories have generated interest and inspiration at OHi for years, and we hope this publication may be similarly received by others.

We also hope that it will arouse interest and inspiration amongst engineers and companies with whom we cooperate throughout the world, by providing updated information about research and technological development at OHi. Each issue will have a main topic, so as to make it possible to illustrate DHl's contribution to the "state-ofthe-art" on the area in question. Perhaps recipients of this publication would find in this some reason to keep it on file for further reference.

to OHi, and we hope to be able to apply advanced hydraulic engineering to this field so as to make a small contribution to the general advance of the technology.

Along these lines the OHi involvement in the design of the gas pipeline in the Danish North Sea has led to the application of advanced mathematical modelling of waves and currents, including application of three-dimensional wave theory to pipeline stability design, resulting in a comprehensive and rational, as well as cost effective new approach. The publication will also contain a number of short notes presenting miscellaneous recent activities at OH I. We hope you will find at least some interesting reading here, and would welcome any comments you may have, critical or otherwise, to the material presented and the form of presentation.

Sincerely Danish Hydraulic Institute

The main topic of this first issue is offshore engineering.

This area is rapidly gaining in importance to Denmark and Torben S0rensen Director

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