1. Richard Scott Shaun Cartledge Steve Marples Vajont Dam Disaster

2.  The Vajont Dam was completed in 1960  It is one of the highest dams of its kind in the world  Dam capacity was 168 million cubic metres

3. Vajont Dam Disaster Longarone was one of several towns in the valley Mount Toc was known to its people as “the mountain that walks” The people feared its affect on the dam Geologists and engineers reassured them They predicted the mountain would settle very gradually Officials planned to control Mount Toc’s movement by raising and lowering the water level in the reservoir

4. Vajont Dam Disaster Heavy rain in October 1963 Ground water runoff was hampering attempts to lower the water levels October 8 th : The creep of rock mass had reached 40cm a day

5. The Disaster - October 9 th : 60 technicians and office staff monitored movement of mountain Reservoir was 2/3 full containing 135 million cu. m of water At 10.41pm giant slabs of rock slid down the mountain on the northern slope Slide left exposed rock behind 45 second slide down slope into reservoir Mass of sliding material was 600 million tons

6. The Waves  Wave was divided into three parts  1 st and most powerful wave travelled towards Casso Casso was protected as it sits high above the reservoir  2 nd part travelled towards Erto  3 rd part travelled towards Longarone 60 technicians and office workers were killed instantly

7. Longarone  30 million cubic meters of water overtopped the dam  Wave was at least 200m above the top of the dam!  Water, mud, rock and timber in wave created a powerful blast of wind in front of water wave  The wind power produced was compared to two Hiroshima bombs  Wind destroyed buildings and killed most people  In excess of 2000 deaths in Longarone

8.  After the disaster the whole town of Longarone was flattened  Over 2000 deaths  One house survived due to it being on a hill Vajont Dam Collapse - Effects

9.  The engineers designed the dam well, but didn’t understand what was happening in the valley walls  The clay in the valley became wet and therefore slippery, lowering the friction angle and causing the landslide.  The dam withstood the pressure of the surge  The top 1m of concrete was eroded away due to the immense frictional forces created.  Evacuation was possible given the long time period that valley movements were observed  It is likely that the increasing level of the reservoir also increased clay layer pore pressures, reducing the effective strength and shear resistance. Vajont Dam Collapse- Engineering

10.  After the disaster, 3 engineers were found guilty of multiple manslaughter  Longarone was rebuilt in same location, with mostly new inhabitants  Vajont dam still stands, but has not been used to generate hydroelectric power since the disaster in 1963. Vajont Dam Collapse- Aftermath