Heavy lifting or lowering on a worksite can be complex at the best of times, but when it involves a heritage-listed building, the process becomes even more complex. A new project in Newcastle is a prime example, but with the right expertise, products and a specialised synchronised hydraulic jacking system, the project was completed successfully.
Richard Crookes Constructions (RCC) is constructing a new urban village in Newcastle. The project includes the refurbishment of a heritage building that dates back to the 1890s and once housed a David Jones department store.
The heritage listing constraints meant RCC had a challenge on their hands, as the existing timber floor structures had to be maintained.
Three 370m2 floors in the building had to be lowered up to three meters, without damaging the external façade. The company considered two options to lower the floors: disassembling and rebuilding the floors at a new level, or hydraulically lowering them.
After speaking to the temporary works engineering team at Coates, RCC chose the latter option and engaged the firm to design and install propping and a synchronous hydraulic jacking (lifting) system.
“Using the hydraulic method with Coates was about 45% cheaper and 50% faster,” says Patrick Barry, Project Manager at RCC.
Coates used a Universal Propping System, designed for flexibility and durability, accompanied by the EVO Synchronised Lifting System which helps lift and weigh safely and with precision. The floors were cut away from the walls, leaving them “floating” in the air, supported by the props and hydraulic jacking system.
As each one was lowered, new steel columns had to be installed and the floor tied back into the existing brick façade. Then, the props were able to be removed.
According to Coates Engineering Manager Neil Gujare, they synchronously lowered the first floor by 250mm and then modified the props, lowered by 250mm and then modified the props and so on.
This took longer than anticipated, so for the second level, they adjusted their method. “For the second level, we included light-duty tilt props and titan props with set heights to speed up the process, which in turn saved the client money,” says Neil.
One of the main benefits of this system is that the props could be monitored wirelessly, allowing Coates and the project’s consulting engineers to verify the loads remotely. The pressure and extension of the cylinders are transmitted back to a central computer control system, which opens and closes control valves as needed, correcting any minor fluctuations in the cylinder size.
Meanwhile, RCC valued working with one supplier to design, supply, install and certify the propping and jacking system, says Patrick. “Every element that Coates did was perfect,” he says. “It would’ve been a lot harder had we split it up into multiple packages.”
With the temporary works now complete, the project is due for completion at the end of 2021.