< Back

MURRAY AVENUE, NEWCASTLE EAST

 

Architect: Curious Practise

 

Builder: GTS Constructions

 

Engineer: Izzat Consulting Engineers

 

Heavy Foundations were engaged by GTS Constructions to complete the foundation piles and the contiguous pile wall for a residence at 3 Murray Avenue, Newcastle East. The contiguous pile wall acts as a retaining structure at the rear of the first level that comes in off Shortland Esplanade.

 

The site had a few complexities which made it challenging, these included:

- A 6m wide site for the full length of the job. Therefore excavators could not move past each other and needed to be positioned and strategically coordinated to ensure efficiency and continuous flow of work.

- The steep hills and existing retaining structures which created significant drops across the site. This influenced how the job was completed as only select machinery was able to reach far enough to complete the drilling. 

- Hard rock at the front of the site made for slow drilling

- Hidden underground slabs and existing infrastructure that was not anticipated

- Due to the age of the properties in the area, neighbouring properties were typically founded on bricks or shallow footings and therefore extreme caution was taken not to undermine these properties. This meant that staging of the bored piers was also required as the sand had to be moved in stages. 

- The steep banks on neighouring properties also caused some constructability issues due to finishing  height of contiguous pile walls being much lower than neighbouring land. Therefore temporary shoring walls were required above the wall to prevent sand migration from their block of land onto the site. 

 

The wall piles were completed in the following stages:

 

      BEFORE WORKS COMMENCED: 

 

 

STAGE 1: Side Wall Piles from the top bank

The first stage of works at Murray Avenue, Newcastle was completion of the wall piles on the northern and southern boundaries of the job, on the western half (the high side of the job). Due to the reach of the excavator, the furthest pile that could be completed from the top was about a third of the way down. Completing these piles was slow, tedious work as the piles had a tendency to want to creep down the hill upon starting.

 

          

 

STAGE 2: Back Wall Piles from the top bank

The second stage of the job was the back wall of the pile wall, it ran from the north to south boundary. To complete the back wall, the CFA rig was floated in as it would be able to complete the piles much more efficiently than the excavator. The CFA rig needs a level platform to work off at approximately the same height as the finishing height of the pile. This is typically relatively easy to setup as the support excavator can move the dirt around, and create batters on either side of the working area. However, this was difficult to achieve on this site as the excavator could not walk around the drilling rig to build the platform, there was also extreme caution required with not taking too much dirt away from the neighbouring property boundaries due to their footings. Access to the corner piles was also difficult using the drilling rig due to the available reach from the working platform.  The platform would either need to be built on the eastern side of the job, further away from the neighbouring shallow house foundations and closer to where the spoil would be required, or on the western side of the piles which would mean the machine wouldn’t need to track over the starter bars of the piles on completion of the wall.

 

STAGE 3: Wall piles from the eastern side of the job, near Shortland Esplanade. 

The last stage of the wall piles was the eastern side piles. These were completed using the excavator from the bottom of the hill. The spoil that was generated from drilling the side and top piles was used to build a ramp that would allow us to take the excavator from the top of the job to the bottom. This ramp was then also used to assist in reaching up the hill to finish the remaining piles on both boundaries.