VST used on Portuguese bridge
First publishedin World Highways
Bachy Soletanche is currently carrying out its biggest job in the [English] Midlands.
PERI says that its new VST heavy-duty shoring tower serves as load-bearing scaffold for the large bridge and civil engineering projects.
Each leg on the VST (VARIOKIT Shoring Tower) system can carry a load of around 600kN (the weight of about 60 VW Golf cars or one Leopard-2 tank), and the extremely flexible modular system can be assembled as segmental sections, towers or shoring tower frames for heights up to 40m.
As part of the VARIOKIT engineering construction kit, PERI has used multi-purpose system components for the heavy-duty shoring tower, which are rentable. PERI says that pins and bolts as standardised connecting parts allow simple and rapid assembly, making special components and time-consuming in situ welded structures no longer necessary.
The system was unveiled at bauma 2010, and PERI says it can now report on the first practical applications, which include the Grand Ice Rink in Sochi, Russia, and a motorway bridge across the Rio Sordo, Vila Real, Portugal.
In north Portugal the 412m long motorway bridge spanning the Sordo Valley has been designed as a five-section bridge on two separate superstructures. The pre-stressed concrete hollow box sections are being realised by means of two different construction methods: the three middle bridge segments use the balanced cantilever method while falsework is used for the respective edge sections. The superstructure formwork and the shoring structure are based on the VARIOKIT engineering construction kit.
Support for the superstructure formwork with 10-25m centre spacings is provided by the new VST heavy-duty towers, which are designed as four-legged towers with heights between 6-30m, and feature basic grid dimensions of 2m², 2m x 3.75m and 2m x 7.5m, optimally matched to meet the topographical and static requirements. Up to 2,500kN per tower are safely transferred into the ground.
Strengthening at selective points allows leg loads over 600kN, and according to PERI this minimises material requirements as well as the assembly work for the falsework.
Assembly took place using variable 1.25m to a maximum 10.25m sections, which were delivered as pre-assembled shear frames to the construction site, extended on the ground to form tower segments, and then lifted into position. Larger heights were subsequently realised through the addition of extra sections lifted into position by the crane.
PERI's Portuguese engineers combined VARIOKIT heavy-duty shoring towers with the PERI UP Rosett modular scaffold.
In Sochi, setting for the 2014 Winter Olympic Games and Paralympic Winter Games, roof construction of the new ice arena is supported by a total of 17 steel girders, each one up to 12m high. These bridge the complete 94m stadium width and have a spacing of 7m to 7.5m. Two free-standing, 37.5m high shoring tower frames from the new PERI VARIOKIT heavy-duty shoring system serve as assembly support in the respective one-third and two-thirds of the length.