Perth Residential Shoring Solution Project - Coates

A robust and flexible shoring solution for a prestigious Perth riverside address

The Project

This unique project will deliver a new luxurious 1500sqm single-family residential dwelling on the banks of the Swan River in Claremont. The 60-metre-long, split-levelled home is due for completion in 2021.

The Problem

Ensuring the integrity of the basement structure during demolition and rebuild was the greatest complexity at Freshwater Bay. A total of 100 9m-deep piles that line the perimeter of the excavation site needed to be braced and supported while demolition and excavation took place.

“With the property wedged between two luxurious multi-storey homes, retaining and supporting the structures on either side was always going to be a major challenge,” explains Exclusive Residence Director John Douglas. “The depth of the excavation and proximity of the neighbouring properties meant we required a robust shoring solution.”

According to Coates Engineer – Temporary Works, Douglas Norton, these factors were exacerbated by the need to excavate and build below ground, on an acutely sloping 15m-wide block with limited access. “The back of the property is bordered by the river – which floods during winter – and the front is bound by a school zone on a busy suburban street. This restricted deliveries and the movement of personnel during school hours,” Mr Norton explains.

Many other potential issues lay hidden below ground during design. The level of detail that could not be seen or designed due to unknown factors beneath the surface has been a consistent concern for the project team, and required considerable input from all consultants to resolve. The Solution:

The property at Freshwater Bay required a flexible and robust shoring solution to allow for partial demolition of the existing property, and construction of a new structure on this challenging riverside site.

Throughout the two-year design and planning phase Coates worked as an integral part of the design team, alongside the property owner, builder and two top-tier engineering consultancies to design an effective solution.

Robust and efficient

In May 2019 Coates' heavy duty Hydraulic Strut and Waler System was successfully installed on site. This system, which took 1.5 days to install, featured four 12 metre long hydraulic struts that remained in place until a suspended slab could be poured to take over the job of supporting the piles.

According to Mr Norton, the efficient temporary works installation meant this solution had minimal impact on the construction space or the scheduled work, and the project team could deliver a surprising amount of work in and around the shoring.

“Efficient temporary works installation meant that crane down tine was minimised, less traffic control was required, street disruption and truck waiting time was kept to a minimum and work could be achieved within the school day working restrictions” he explains.

Once the slab had been poured and was providing adequate support, the retractable shoring components could be dismantled and removed piece by piece from underneath the slab – again in just two days.

Collaborative

The effective delivery of the shoring solution was made possible by senior personnel from Coates, our contractors, service providers and clients opting to meet at site prior to work commencing. “The collaborative approach of the entire project team allowed each working window to be planned at least 14 days in advance.”

Data-driven

Telemetry sensors embedded in this hydraulic shoring system allowed the project team to periodically monitor the compressive force being applied to each steel strut. This technology meant that changes could be detected, and offered assurance that the designed solution could support the required loads.

Compatible

With an expected 350 consultants and tradespeople involved in delivering this project, systems and project integration needs to be seamless. “The proven safe and efficient delivery of Coates’ Hydraulic Strut and Waler System was integral to its selection. We also value the superior support process it could provide to other systems we considered” says Mr Douglas.

Comprehensive

Working with Coates meant that the job would get done, safely and to schedule. “By taking ownership for an end-to-end shoring solution, our client could achieve all of the temporary works requirements – including concept development, design, supply, installation and removal – by working with just one provider,” says Mr Norton.

“Our experience working with Coates was positive from start to end” Mr Douglas concludes. “They delivered on time and I always found the team to be friendly, efficient and professional.”