Gulf Construction Online - Peri at forefront of major projects

Germany and the Middle East

Saadiyat Bridge, one of the widest in the world, employed Vario GT side formwork.

Peri at forefront of major projects

A number of massive infrastructure projects in the region speak for Peri’s leadership in formwork and shoring technology. Its cost-effective technology backed by skilled engineers and site supervision are some of its key attractions.

01 March 2012

PERI has proven to be among the top formwork and scaffolding suppliers in the Middle East especially in the area of infrastructure projects. The company has been able to tackle formwork and shoring challenges regarding weight-load and static requirements with project-oriented solutions and engineering support in a number of bridge projects in the region over the past few years.

Over the past decade since it set up operations in the UAE, Peri has been involved in a large variety of bridge projects, all of which showcase the depth of knowledge and expertise of the German formwork and scaffolding expert within the region.

Among such projects is the Northern Ring Road, which is under way in Al Ain, the recently completed Saadiyat Bridge in Abu Dhabi and the VIP access bridge at Meydan City in Dubai.

The Northern Ring Road will connect the city to Abu Dhabi emirate’s transport network with bridges, tunnels, and intersections. The construction includes a new dual carriageway, a three-lane flyover, three underpasses, wadi bridges and the upgrading of the existing ring road. The contractor is Abu Dhabi-based Saif Bin Darwish Company.

The PD8 slab table was used as shoring for the VIP access bridge.

The formwork solution for the superstructure is realised with GT 24 formwork girders, SRU steel walers and SLS spindles.

“This construction could be accurately adapted to the structure’s geometry. Peri’s PD8 shoring towers, which are extremely cost-effective as large units and offer high clearances, support the formwork,” says a spokesman for the company.

Peri formwork was also utilised in many areas of Meydan City, one of them being the VIP bridge. The city is home to new Meydan Race Course, which with a capacity of 60,000 spectators hosted the Dubai World Cup for the first time in March 2010.

The contractor Dutco Balfour Beatty on the VIP access bridge had under five months to build the 750-m-long and 25-m-wide (49 m in some areas) structure, which is shaped like an arch. Therefore, the box girder height varies between 2 m and 4.5 m. The bridge formwork was supported by PD8 towers which rose to 10 m in the highest areas. The slab decking was done with Multiflex using VT 20 girders.

“The challenge in this project was the middle part of the main bridge,” says the spokesman. “Normally the concrete in the centre of the bridge is the last to be poured and connects the piers. However, due to various reasons, this couldn’t be done in the VIP bridge project and so the middle section had to be concreted without being connected to the piers. As such, the entire load was carried by the PD8 towers and stabilised through push-pull props. Only by scheduling the project in this unusual way, could the contractor complete the project on time.”

GT 24 girders, SRU steel walers and SLS spindles form the superstructure of the Northern Ring Road Bridge.

Saadiyat Bridge

Among the largest and most challenging bridge projects handled by Peri in the Middle East, however, is the iconic Saadiyat Bridge. It connects Abu Dhabi City and Saadiyat Island, which lies about 500 m off the coast. With a length of 1,455 m and an impressive width of 60 m, it is one of the widest bridges in the world.

Eight foreland piers in the west and a total of 11 on Saadiyat itself served to support the three pre-stressed concrete hollow boxes with spans ranging between 45 m and 135 m. The main bridge has a span of 200 m and is carried by two V-shaped, 20-m-high identical sets of piers per section.

“The formwork and scaffolding solution for the individual supports, with inclinations of more than 27 degrees, consists of two sets of Vario GT 24 side formwork, a forward-inclined Vario formwork element with integrated working platforms as well as a reverse-inclined raised formwork unit. Due to the high concreting loads, this was carried on Peri UP shoring,” explains the spokesman.

The bridge piers have been constructed alternatively in four climbing steps with concreting cycle heights of 4.7 m as well as by 2.44 m in an outward direction in each case due to the inclination of the piers.

The Peri concept allowed the supporting frame construction to be pulled outwards on the steel girders after striking had been completed as though being guided along rails. For efficiently achieving the required supporting and platform levels, three tower modules – each with a 2 m base and a 4.65 m extension height – could be vertically coupled together. “Connections were carried out with the time-saving Peri section spindle and the extension units could, therefore, be accurately adjusted to the required height. Through the extensively dimensioned moving units, it was possible to construct very cost effectively a total of 48 casting segments with only four sets of formwork,” he points out.

Peri’s know-how has also been in demand for all other construction phases as well – for both abutments, the numerous bridge piers in the foreland area through to the superstructure formwork.

For the construction of the pre-stressed concrete hollow boxes, three different building methods were used: the western foreland bridge was realised using the incremental launching method; for the superstructure on Saadiyat Island in the east, false work served as a flat and even support; while the large spans in the middle bridge section are concreted by means of the balanced cantilever method.

The company offers standardised, rentable system components and construction-compliant connecting means, supporting structures to deliver cost-effective formwork to meet project requirements and client expectations. With well-trained design engineers, as well as continuous site supervision along with large stock capacity, Peri is able to support any construction project to ensure timely completion of the project.

“Peri systems fulfil the needs of any construction company for flexibility and high productivity,” concludes the spokesman.