Lifting the top station of 3S Pardatschgrat aerial lift in Ischgl, Austria
The building rests on a total of 26 piers. With the reinforced concrete slab and additional cross members, these piers form a solid frame structure. Because of the decline in permafrost, the piers settled by between 0 and 80 millimeters during the 2015 summer season. The possibility of correcting settlement had been considered in the design of the top station’s piers.
Because of the effect of the frame, building settlement and the corrective measures caused a considerable relocation of loads on the foundations. The challenge for us was to compensate for local settlement to prevent impermissibly high loads on the foundations. First of all, the resultant cavities were filled by injecting material under the foundations in order to increase load-bearing capacity.
Then we installed two hydraulic lockingring jacks and an electronic position sensor on each of the 19 piers. Via hydraulic hoses and data cables, the total of 38 jacks and 19 position sensors were connected to the central processing unit of our computer-controlled synchronized lifting system. From this central unit, we were then able to lift each individual pier millimeter by millimeter and monitor the effects on the other pier loads at the same time.
As a result, the top station was restored precisely to its previous level.