Green Duba Integrated Solar Combined Cycle Power Plant

Posted on November 4, 2022March 15, 2024 by Sir Gwi

Green Duba Integrated Solar Combined Cycle Power Plant

Duba ISCC Green Power Plant 1 is a large power infrastructure project taking place in the North West of Saudi Arabia, on the Red Sea. The ISCC (Integretad Solar Combined Cycle) technology is adding 50 MW of solar power to the gas & steam turbine generating 500 MW.

For that project, Dextra supplied Double Corrosion Protection Ground Anchors used as a permanent anchoring solution for the excavation works preparing the pumping chamber. A total of 264 anchors (Grade 1080/1230, Ø32 & 40mm) have been supplied and installed on 4 layers.

The Double Corrosion Protection anchors supplied for this project were pre-grouted at Dextra factory (first layer of grout between steel bar and HDPE sleeve). The pre-grouted segments were reconnected at site thanks to couplers. Pre-grouted anchors not only save time and money on site operations, they also allow an overall better anchor quality by performing the first grout layer in a factory-controlled environment.

Installation at site was carried out by foundation contractor BAUER, which performed drilling, lifting, installation, grouting and post-tensioning operations. Dextra offered guidance during the early steps of the installation by sending a team of geotechnical specialists at site.

The general sequence of installation is the following (illustrated in pictures below):

After unpacking from shipping racks, splicing of segments with couplers, covered by heat shrink sleeves.
Transportation of assembled anchor from assembly to site to lifting area (13kg per linear meter).
Wiring cable at the head of anchor to control the descent. Grouting pipe also pre-installed along the anchor.
Inserting the 30 meters anchor into drilled hole together with grouting pipe.
After grouting and stressing, a head cap filled with grease is installed on the anchor head, maintain the anchor fully isolated from the corrosive outside environment.

For more information about our excavation and ground solutions in the Middle East, please contact our Dubai office.

Doha Metro Msheireb Station

Posted on November 4, 2022March 15, 2024 by Sir Gwi

Doha Metro Msheireb Station

Msheireb Station is the major interchange station of the Doha Metro. Located in Downtown Doha, it connects all of three lines (Red, Green and Gold) and will provide a gateway 2022 FIFA World Cup 2022 stadiums

The Msheireb Station will become one of the largest subway stations in the world by size.

Soft-Eyes for TBMs

For this major project, Dextra engineered and supplied between 2013 and 2015 8 large ASTEC GFRP Soft-Eyes, of a diameter of 8 meters each. Soft Eyes are cages of GFRP rebar, positioned into the D-Walls in-between steel segments. GFRP Soft-Eyes allow Tunnel Boring Machines (TBMs) to go through in a minimum time as the bars can be easily crushed by the tunnel machine.

Tie-Back anchors

To anchor the massive d-walls and prevent any soil displacement during excavation works, Dextra also supplied its ASTEC Active Anchors (AAA). Those innovative post-tensioned GFRP-based anchors, have the benefits of being cut by the Tunnel Boring Machines or standard excavation equipment. Because it can be easily cut, it doesn’t need to be removed from the ground, even when used for temporary applications.

In the case of the Msheireb stations, multi-tendons anchors (10 per anchor on this project) have even been installed in the center of Soft-Eye to anchor the D-Wall. Those anchors were also cut during the tunneling break-through (visible in the video below). In total 150 anchors were installed in the station.

Nagpur Metro, Zero Mile Metro Station

Posted on November 3, 2022March 14, 2024 by Sir Gwi

Nagpur Metro, Zero Mile Metro Station

Nagpur Metro Zero Mile Station in a mixed-use transportation/parking/commercial project taking place in the city of Nagpur, Maharashtra state. It is located on the new metro line crossing the city from North to South. The Zero Mile Station is a subway station combined to a 12-stories building which will host commercial areas and a car park of a capacity of 430 vehicles.

For that project, Dextra has been involved in 2017 for the supply and installation of ground anchors for the stabilization of ground around excavation area.

Dextra supplied its innovative ASTEC (FRP) Active Anchors solution (AAA), a special type of ground anchors which, in the case of temporary applications, can be left in the ground after the project ends, even if those stretch beyond property line or come across future tunnels.

Indeed, one main benefit of the FRP anchor bar is to make the anchor entirely cut-able by conventional excavation equipment, making it the best substitute to conventional removable anchors which are steel anchors that needs to be removed from ground by brute force at the end of project.

Dextra ASTEC Active Anchors are light to transport and can be carried to their final location by workers. Once inserted in the drilled hole, each anchor is grouted and later stressed by the use of conventional PT strands connected to the FRP anchor. After installation, the anchor can remain in the ground, unlike conventional removable anchors which require additional project management and generate end-of-life anchor removal costs.

For more information about Dextra anchoring solutions in India, please contact our Mumbai ofice.

Tag: active anchors steel