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Show ! gJI*& gft J1 1 j * - • ,-; Z.;£,„,.:„..••%,. ."' '+.-*£*£ " r-**.. *,• * J * - illsiltlljt f - ^ ?% Mm • NH& SBS Fig. 10. Over all view of the destruction at the complex of buildings at the Dalaas rail station. B. Dalaas Railroad Station a) The Building The general situation of the catastrophe of January 1954 is shown in Figure 3. The avalanche struck the front of the railway station building. The western part of the building, still standing, was about in the center of the avalanche. From the distances of objects still intact, the effective width of the avalanche" can be estimated; it amounts to about 120 meters. In view of the flatness and width of the slope this small width is only understandable if one assumes that an avalanche, released from a steep collection zone located higher, penetrated the entire slope without expanding sideways. As a result of the damming action of the undestroyed part of the building, the height of the snow reached about 7 meters ( Figure 11). The extent of the destruction of the building in general is visible in Figure 10. On the east side ( left in Figure 10) the roof was removed, or tipped over toward the rear. The roof fragments lay immediately behind the structure. The lower part of the building, about 12 meters wide and 3.3 meters high, constructed of brick walls 40 centimeters thick, remained standing. Windows and doors together with the frames were pushed inwards. Based upon practical experience with explosive tests, pressures of the order of magnitude of 100 to 200 kg/ m2 are sufficient for these damages. The mass of snow pressed into the interior set up a cross pressure so that connecting doors on the side were crushed and ceilings were raised ( Figure 12). In the case of the single story structure being discussed, because of insufficient wall pressure, obviously overcoming the shear strength is the determing factor for the pushing in of the front wall. Assuming a shear strength of 5 to 10 kg/ cm2 for the masonry, the pressure on the wall surface was 1200 to 2400 kg/ m2 . Behind this part of the rail station building, at a distance of about 15 meters, was a house with a covered veranda. The veranda roof was crushed from above because the snow masses, dammed up by the building standing in front, plunged as if over a spillway onto the veranda roof behind. This force component acting predominantly downward from above is also indicated by the observation that the rest of the building front and even the window panes remained intact. The middle part of the railway station was completely caved in. 10 |