Impact pressures and flow regimes in dense snow avalanches observed at the Vallée de la Sionne test site

摘要: [1] A fundamental problem in avalanche engineering is to determine the impact pressures exerted on structures. This task complicated because snow avalanches flow a variety of regimes, primarily depending temperature and moisture content. In this paper we address by analyzing measured pressures, velocities, depths five Vallee de la Sionne avalanches. The measurements are made 20 m high tubular pylon instrumented with high-frequency pressure transducers optoelectronic velocity sensors. observed avalanches, find both subcritical supercritical regimes. Typical Froude numbers were smaller than 6. regime (Fr < 1) characterized plug riding above highly sheared basal layer. large velocity-independent contradiction calculation procedures. Pressure fluctuations increase depth, indicating kinematic stick-slip phenomena which largest at Supercritical regimes (1 Fr 6) all over depth. velocity-dependent. We derive relationships governing as function number, therefore regime, encompassing