NRC Publications Archive Archives des publications du CNRC Ice engineering and avalanche forecasting and control Gold, L. W.; Williams, G. P. This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur. Publisher’s version / Version de l'éditeur: Technical Memorandum (National Research Council of Canada. Division of Building Research); no. DBR-TM-98, 1969-10-23 NRC Publications Archive Record / Notice des Archives des publications du CNRC : https://nrc-publications.canada.ca/eng/view/object/?id=50c4a1f1-0608-4db2-9ccd-74b038ef41bb https://publications-cnrc.canada.ca/fra/voir/objet/?id=50c4a1f1-0608-4db2-9ccd-74b038ef41bb Access and use of this website and the material on it are subject to the Terms and Conditions set forth at https://nrc-publications.canada.ca/eng/copyright READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site https://publications-cnrc.canada.ca/fra/droits LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB. Questions? Contact the NRC Publications Archive team at [email protected]. If you wish to email the authors directly, please see the first page of the publication for their contact information. Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à [email protected]. NATIONAL RESEARCH COUNCIL OF CANADA ASSOCIATE COMMITTEE ON GEOTECHNICAL RESEARCH ICE ENGINEERING AND A VALANCHE FORECASTING AND CONTROL PROCEEDINGS OF A CONFERENCE HELD AT THE UNIVERSITY OF CALGARY 23-24 OCTOBER 1969 SPONSORED BY THE SUBCOMMITTEE ON SNOW AND ICE TECHNICAL MEMORANDUM NO. 98 COMPILED BY L. W.. GOLD AND G. P .. WILLIAMS OTTAWA NOVEMBER 1970 PREFACE Avalanche research and ice pressures against structures were the topics chosen for discussion at the Sixth Conference on Snow and Ice sponsored by the Snow and Ice Subconunittee of the NRC Associate Committee on Geotechnical Research. These topics were very suitable for the first of the Subcommittee's conferences to be held in Western Canada. The need for information concerning avalanches, avalanche hazard forecasting and avalanche defence is increasing due to develop­ ment activity and growth in winter sports in the mountains of Western Canada. The papers presented to the Conference provide a good review of the principal avalanche problems and the current state of avalanche research in Canada and United States. The forces that ice can exert against structures were the subject of the Committee's Fifth Conference on Snow and Ice. * Recent interest in the possibility of Arctic sea routes, and the need to review the des i gn criteria for ice pressures for bridge piers, has brought about a rapid development of this subject. Much of the interest and activity has been in the West, a nd so it was appropriate to spend one day of the Conference on reports and discussions of work that had been done since the Fifth Conference. Five of the papers presented to the Conference are to be published in the Canadian Geotechnical Journal. Extended abstracts only of these papers are presented in these Proceedings. The Associate Committee wishes to express its appreciation to the authors of papers, discussors, and all others who participated in the Conference. It wishes also to express its appreciation to Miss J. Butler for her assistance to Messrs. Gold and Williams in the preparation of this Technical Memorandum. C. B. Crawford, Chairman, Associate Committee on Geotechnical Research * Ice Pressures Against Structures, T. M. 92, Associate Committee on Geotechnical Research, National Research Council of Canada, Ottawa 7, Canada. TABLE OF CONTENTS ICE ENGINEERING SESSIONS OCTOBER 23 SESSION I: - Chairman: Dr. R. F. Legget, Past-Chairman, Associate Committee on Geotechnical Research 1. 1. Classification of River and Lake Ice Based on Its Genesis, Structure and Texture. {Abstract}. - Professor B. Michel and R. O. Ramseier, Laval University, Quebec City.. 1 1. 2. A Tentative Field Classification of Lake and River Ice. - G. P. Williams, National Research Council, Ottawa. 5 1. 3. The Process of Failure in Ice. {Abstract}. - L. W. Gold, National Research Council, Ottawa. 12 Discussion {Written} - H. R. Kivisild, Foundation of Canada Engineering Corporation, Toronto. 13 SESSION II: - Chairman: Professor G. S. H. Lock, Department of Mechanical Engineering, University of Alberta II. 1. Movements in Continuous Lake Ice Sheets and Temperature Gradients in an Ice Sheet. - Professor S. S. Lazier and F.A. MacLachlan, Queen's University, Kingston........ 17 II. 2. Observations on Break-Up of River Ice in North Central Alberta. {Abstract}. - Professor J. Nuttall, University of Alberta, Edmonton, Alberta....... ................. 36 II. 3. Alberta Studies of Ice Pressure on Bridge Piers. {Abstract}. - C. R. Neill, Research Council of Alberta, Edmonton. .......................................... 38 II. 4. Effective Force of Floating Ice On Structures. - J. L. Allen, Monti, Lavoie and Nadon, Montreal, P. Q. 41 II. 5. Analysis of Forces in a Pile - Up of Ice. - J. L. Allen, Monti, Lavoie and Nadon, Montreal, P. Q. ..... ..... .. .. 49 TABLE OF CONTENTS (continued) II. 6. Vibration of a Floating Ice Sheet. - D. E. Nevel, U. S. Army Terrestrial Science Center, Hanover, N. H. 57 II. 7. The Flexural Strength of Sea Ice as Determined from Salinity and Temperature Profiles. - G. E. Frankenstein, U. S. Army Cold Regions Research and Engineering Laboratory, Hanover, N. H. ........................... 66 A VALANCHE SESSIONS OCTOBER 24 SESSION III: - Chairman: G. Hattersley-Smith, Defence Research Board III. 1. Problems in A valanche Forecasting and Control on the Trans Canada Highway in Glacier National Park. - W. E. Bottomley, National and Historic Parks Branch, Department of Indian Affairs and Northern Development, Calgary, Alberta. ... ................................. 74 III. 2. Mining vs . Avalanches - British Columbia. - J. W. Peck, Chief Inspector of Mines, British Columbia Department of Mines and Petroleum Resources, Victoria, B. C. ...... 79 III. 4. A valanche Problems in Canadian Recreation. - C. B. Geisler, Canadian Ski Patrol System, Calgary, Alta. 91 III. 5. Planning Defences Against Avalanches. (Abstract). - P. Schaerer, National Research Council, Vancouver, B. C. 97 III. 6. Avalanche Problems at Mine Sites. - M. M. Atwater, A valanche Consultant, Olympic Valley, California. ...... 99 SESSION IV: - Chairman: P.A. Schaerer, National Research Council IV. 1. Principles of Avalanche Forecasting. - E. R. LaChapelle, University of Washington, Seattle, Washington. .......... 106 IV. 2. On Contributory Factors in Avalanche Hazard Forecasting. (Abstract). - R.1. Perla; Forest Service, U. S. Department of Agriculture, Alta, Utah. ............................ 114 TABLE OF CONTENTS (continued) IV. 3. Avalanche Hazard Evaluation and Forecast, Rogers Pass, Glacier National Park. - V. G. Schleiss and W. E. Schle is s , National and Historic Parks Branch, Department of Indian Affairs and Northern Development, Rogers Pass, B. C. ... 115 IV. 4. A Pilot Study of Weather, Snow, and Avalanche Reporting for Western United States. - A. Judson, Forest Service, U. S. Department of Agriculture, Fort Collins, Colorado. 123 IV. 5. A Process-Oriented Classification for Snow on the Ground. - R. Sommerfeld, Forest Service, U. S. Depart- ment of Agriculture, Fort Collins, Colorado. .... ....... 135 IV. 6. A Two-Dimensional Approach to Avalanche Problems. ­ Professor H. W. Shen, Colorado State University, Fort Collins, Colorado. ..... ......................... 140 Conference Summary -- Dr. R. F. Legget 153 Programme Participants and Registrants 155 1. 1. CLASSIFICATION OF RIVER AND LAKE ICE BASED ON ITS GENESIS, STRUCTURE AND TEXTURE Bernard Michel* and Rene O. Ramseier Depar ternent de Genie Civil, Urri ve r s ite Laval Quebec, P. Que. (Abstract) ** There is no classification of river and lake ice that takes into account simultaneously the history of ice formation, the structure of the ice cover and the texture of the various types of ice. The classification presented in this paper is an expanded version of that prepared by Michel (1). The classification has three main aspects: (1) definition of river and lake ice terms in a natural genetic scheme; (2) description of the formation and physical properties of the three important ice layers; (3) description of the textures of the various ice types found in ice covers. GROWTH PROCESS AND FORMS OF ICE Any genetic classification of ice must be based on a recognition of the dynamic, physical and mechanical factors which interact in the forma­ tion of the ice cover. There are two modes of ice co ver formation. The first one occurs in an undisturbed body of water such as a lake or river with laminar flow. Under these conditions, a solid continuous ice sheet is formed with a uniform structure in the horizontal plane. This ice sheet may originate from border ice or plate ice formed on the water body. In rivers where there is turbulent flow the formation is more dynamic and comes mainly from the accumulation of frazil slush, pancake ice and ice floes. Wind and wave action may also cause a similar process in lakes and coastal regions. An ice cover may be in the form of a continuous ice sheet or it may be made up of unconsolidated ice accumulations. If the accumulation is major it is called an ice jam. If it refreezes, it is a hummocked ice cover. In certain cases great amounts of slush accumulate under an ice cover in zones of low flow velocity and form underhanging dams. * Some of the material presented is part of a D. Sc. thesis by R. O. Ramseier at the Urriver s i.te Laval. ** To be published in The Canadian Geotechnical Journal, Vol.