Kings Square precinct is formerly the site for Perth Entertainment Centre on Wellington Street next to the bus station and railway station. It forms part of the Perth City Link project, an urban renewal and redevelopment by Metropolitan Redevelopment Authority with the intention to enhance vibrancy by connecting Perth city centre and Northbridge.
Kings square precinct is packaged into 7 parcels of buildings construction with basement car parks. The groundwater table is high with the presence of Acid Sulphate Soils which is the remnant of the lake system in that area.
CMW carried out retaining wall and foundation designs and testing for packages KS1, KS2 & KS4 as detailed below:
- Cantilevered secant pile wall using the continuous flight augering technique
- Foundation mono-piles (bored piles) up to 1800mm diameter and 43m depth with 13.5m rock socketing in Kings Park Formation
- High strain dynamic testing (PDA) on 4% of foundation piles
- Pile integrity test (PIT) for all foundation piles at package KS2; and
- Sheet pile wall for localised lift, hoist and crane base pits below excavation levels.
As the foundation and retaining wall design are highly optimised with large diameter bored piles and cantilevered secant pile wall in high ground water condition, the construction works were closely monitored. Competent rock sockets, and quality concrete were ensured with pile testing program.
Monitoring of deflection of the retaining wall were carried out to check the design performance of the wall.