The Design of Avalanche Protection Dams .Pdf
The design of avalanche protection dams. Recent practical and theoretical developments 1-DRAFT some sections still remain to be written, the document shows the intended section structure and contains draft introductory sections, sections about the design of deflecting and catching dams, and braking mounds, sections about impact pressures on walls, masts and other narrow constructions, appendixes about overrun of avalanches at Ryggfonn, loading of obstacles and a subsection about Iceland in an Appendix about laws and regulations July 25, 2006 1 Photographs on the front page: Top left: Mounds and catching dam in Neskaupstaður, eastern Iceland, photograph: Tómas Jóhannesson. Top right: A deflecting dam at Gudvangen, near Voss in western Norway, af- ter a successful deflection of an avalanche, photograph: ? ???. Bottom left: A catching dam, deflecting dam, and concrete wedges at Taconnaz, near Chamonix, France, photograph Christopher J. Keylock. Bottom right: A catching dam and a wedge at Galtür in the Paznaun valley, Tirol, Austria, photograph: ? ???. Contents 1 Introduction 9 2 Consultation with local authorities and decision makers 12 3 Overview of traditional design principles for avalanche dams 13 4 Avalanche dynamics 16 5 Deflecting and catching dams 18 5.1 Introduction . 18 5.2 Summary of the dam design procedure . 18 5.3 Dam geometry . 20 5.4 The dynamics of flow against deflecting and catching dams . 22 5.5 Supercritical overflow . 25 5.6 Upstream shock . 26 5.7 Loss of momentum in the impact with a dam . 31 5.8 Combined criteria . 32 5.9 Snow drift . 34 5.10 Comparison of proposed criteria with observations of natural avalanches that have hit dams or other obstacles .
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