Mondrian Hotel, Burleigh Heads

One of our recent projects with Mosaic is Sinclair Apartments, located along a main arterial road in East Brisbane.

This project involves foundation piling, sheet piling (including ground anchors and deadman piles), together with a dewatering system and management plan.

A special part of the East project includes seven high quality independent living units for people living with Multiple Sclerosis.

We installed sheet piling, anchoring and bracing, as well as providing dewatering services.

ASP Piling was contracted by Construction Control for the piling and dewatering of The Cosmopolitan in Cottontree at Maroochydore. The large parkland and waterfront site has a basement footprint that spreads two street frontages and adjoins the two towers being built. A total of 143 apartments will be spread over the two seven-storey residential towers.

We provided a range of options to our clients based on engineering, cost and site requirements and constraints. A combination of piling options was employed for the retention and foundation solutions, along with Australian Dewatering Systems site dewatering and environmental services.

The secant piling option was used for the section of basement perimeter with a 6-storey commercial building abutting the ‘Cosmopolitan’s’ boundary. Approximately 10-metre deep scant piles were installed with temporary anchoring. Sheet piling options were used for the remainder, a variety of depths and profiles being used based on basement requirements with the two towers having different basement depths. The sheet piles ranged from 6 metre sheets to over 10 metres long with the associated anchoring and removable whalers were used.

Foundation Piles were installed by ASP Foundation Piling across the site and for the crane base. Over 200 CFA piles were installed with our SF65 Soilmec piling rig.

Australian dewatering systems installed a perimeter spear system around the boundary of the site. The dewatering was installed and commissioned in a staged process as the site was excavated. A deep well system was installed to ensure the system would cope with the dewatering requirements as the basement level was excavated below the natural water table depth. In addition to the dewatering equipment, a filtration unit and sedimentation tank were needed and based on electricity availability a fuel cell and generator for a short period. Further, into the project, an Iron Remediation Tank was needed according to the levels indicated in the monitored discharge water. As always, the site had a dewatering management plan in place and compliance monitoring throughout the discharge process.

‘Mercato’ in Byron Bay is leading the way in the area for environmentally friendly commercial space, looking to have a five-star green star rating for the retail and dining precinct. Azzura Corporation engaged Hutchinson Builders for the construction of Mercato in Byron Bay. ASP Piling was contracted to install the retention walls and foundation piling for the basement, and Australian Dewatering Systems for the dewatering of the project.

ASP Piling’s ability to use a combination of piling options to suit a variety of requirements on one site was brought to the fore at Mercato. Hutchinson builders were required to minimise disturbance to roadways and neighbours, whilst allowing the largest basement car-parking footprint possible. ASP Piling’s engineers worked with our clients to come up with a design that incorporated a section of top-down construction, foundation piles, retention piles including both secant and sheet piles, and dewatering for the most cost and time effective outcome. Click here to see the rigs in action at Mercato.

Top-down construction is effective when there is an inability to using anchoring or the ground-level slab is needed immediately. The bulk excavation can continue after the slab is poured, also limiting the need for bracing where the slab is fixed. A section of the Mercato site was needed at ground level throughout construction making top-down construction most effective. Given the overall area and ease of excavation for the remainder of the site, the more traditional bottom up retention and bulk excavation was used for the rest of the site.

Pre-existing buildings close to the site boundary meant that secant piling was used for retention where minimising ground disturbance was necessary. Sheet piling was then used where suitable to keep costs minimised. A total of over 60 lineal metres of secant piling and over 250 lineal metres of sheet piling, both ranging in depths of 7-8 metres was used for basement retention. Additional sheet piling was used for the lift pits. ASP Foundation Piling installed the foundation piles for the project.

Australian Dewatering Systems was engaged to ensure the site remained dry throughout basement construction. The installation of a spear system along with a generator, fuel cell and our environmental equipment, a dewatering management plan and compliance monitoring were all part of the services provided. In keeping with the environmental philosophy behind the Mercato project, ADS has installed a pH, Iron and Sed tank to ensure that all water discharged from site met or exceeded environmental and council standards for the duration of dewatering.