Project Overview
Located near Weipa in Far North Queensland, Amrun’s marine export facility includes a new 650-metre long access jetty and a 350-metre long loading wharf. Built in 2017 by McConnel Dowell Constructors, the offloading wharf is comprised of seven prefabricated steel jackets that are supported using a combination of drilled and driven piles. MMA was subcontracted to provide the structural grouted connections between the jackets and their piles.
The key challenge at this site was its remote location. Weipa is 1100 kilometres from Townsville, largely via unsealed road, so all materials and equipment had to be barged in from Townsville.
MMA's Solution
To deliver the project, MMA made two key contributions. We liaised with the designer engineers at Jacobs to specify a high strength grout based on GP cement. This enabled the dry bulk grout to be supplied in silos. It also reduced wastage on site, removed common issues with the shelf life associated with premixed grouts and ensured the cement was delivered in excellent condition - which is a challenge in the tropics.
Then, we mobilised a dedicated grouting barge from Townsville, complete with a CM2000 batch plant alongside approximately 700Te of cement storage and associated power and air supplies. Extensive pre-planning was vital to the campaign’s success.
Outcome
In total, 324m3 of grout was used to complete the project. As the leading local grouting contractor, we were fully equipped to provide remote site support and emergency inflatable grout packers to ensure our client was able to complete the program on schedule.
The high 16m3/hr flow of the CM 2000 grout spread meant multiple connections were grouted in a shift, reducing our client’s marine spread duration and associated costs.
Technical Details
| Description |
Density (kg/m3) |
Compressive Strength (MPa) |
| Grout (Ordinary Portland Cement & fresh water) |
1920 |
50 |
Key Equipment / Installation Method
- Continuous Mixer CM 2000
- Offshore cement silos
- Custom Inflatable Grout Packers
MMA Innovation / Value Added
Our client faced some difficult technical challenges when their third party supplied grout packers failed on site. At short notice, our engineers designed, fabricated and expedited grout inflatable packers that successfully sealed the base of the jacket legs to keep the project on track.
Upon inflation of our packers, a 4m3 grout plug was set in the annulus to seal over the failed thirdparty packers. These grout plugs were allowed to cure overnight before the remaining 13m3 of the annulus structural connection was grouted.
