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| PERI modular systems for bridge in Slovakia  For the construction of the 767-metre long motorway bridge in the area of the "Centrum" D1 motorway junction, PERI´s Slovakian engineers developed a formwork and scaffolding solution which perfectly suited the on-site requirements. This resulted from the fact that PERI provides one-source formwork, scaffold and engineering services whereby the bridge formwork and falsework were optimally matched. In addition, this means that integrated, load-optimized system solutions can be achieved along with the guarantee of smooth and efficient construction progress. Planning and execution are based as far as possible on rentable PERI modular construction systems – the PERI UP scaffolding system and VARIOKIT engineering construction kit. Construction of the hollow box cross-sections for the superstructure is carried out using PERI UP falsework. The external web formwork together with the cantilever formwork have been created by means of variable latticed frameworks using VARIOKIT system components – so-called raised formwork units. The PERI UP supporting scaffold transfers the loads arising during construction of the superstructure, at heights of between 13 and 15 metres, safely and reliably into the ground. Through its modular structure and metric grid arrangement, the load-bearing system can be optimally adapted to deal with all forces. With 150, 75 and the short 25-centimetre standards, the individual load-bearing capacities of 40 kN per leg can be combined to deal with higher loads - and can be virtually multiplied at will - in both lateral and longitudinal directions, and thus being able to easily adapt to each particular load situation. Even for concentrated load points, as found in the web areas, several standards can be bundled together using system components. The hollow box superstructure is being realised in two casting segments with the help of VARIOKIT raised formwork units. In the first cycle, the bottom plate complete with webs is formed and concreted whilst the carriageway slab and cantilevers are constructed in the second cycle. GT 24 formwork girders, SRU steel walers and SLS heavy-duty spindles have been accurately adapted to the structure´s geometry and falsework adapted, as well as having hinged and friction-locked connections with articulated walers and universal couplings, resulting in the most ideally-suited unit for this purpose. Loads from the working and concreting operations can thus be safely carried into the substructure and reliably transferred downwards. The span width is 34 metres which also represents the length of each individual concreting cycle. For ensuring optimal building progress, the contractor had sufficient scaffold material available for three complete construction phases. While two cycles are always completely scaffolded, the third set of materials is gradually dismantled, transported to and re-assembled in the next section. Due to the different conditions and the large distances between each section, the site crew have dispensed with moving the large area scaffold units by crane. Therefore, the assembly and safety advantages of PERI UP play an extremely important role: low individual weights, as well as assembling the ledgers from a safe and secure position, ensure fast and safe working procedures. VARIOKIT raised formwork units have been designed so that they can be moved suspended together with the crane, and then be easily adapted to the new structure geometry by means of only a few working steps. write your comments about the article :: © 2009 Construction News :: home page |