Banora Point Upgrade (Q954)

Project status: 
Major Project >$25m
Industry sector: 
Infrastructure
Application: 
Roads
Technique: 
Bored Piling/ Hard Rock Drilling
Equipment: 
Track Mounted
Our Client: 
Banora Point Upgrade Alliance
End Client: 
Roads and Maritime Services NSW
Project Time Frame: 
2010
State: 
NSW
Location: 
Pacific Highway - Banora Point - Northern NSW
 
  
 

Key Challenges

  • Drilling sockets in extremely high strength rock up to 400 MPa
  • Implementation of a new drilling system using pneumatic cluster hammers
  • Very congested site conditions
  • Working adjacent to domestic residences (control of noise and dust)

Scope
Foundation works were carried out for:

  • 3 bridges requiring a total of 26 No. 1200 mm diameter bored piles drilled under bentonite to depths of 35-45m
  • 1 bridge requiring a total of 48 No. 1200 mm dia bored piles with temporary casings to drilled depths of1 5-22m
  • 1 bridge (2 abutments) founded on 8 No 550 mm octagonal Prestressed concrete piles driven to depths of 22m
  • 1 bridge requiring a total of 12 No. 1200 mm dia  bored piles with rock sockets drilled using cluster hammer technology to depths of 9-18m with 2 - 4 m sockets into 250 MPa rock.
  • Soldier pile retaining wall with a total of 150 No. 1200 mm dia bored piles at 3m centres drilled using  cluster hammer technology , piles ranged from 12 to 25 m depth with rock sockets of 3 - 8 m length into rock of up to 400 MPa.  (link to website section 3.1.1 hard rock drilling)
  • Works undertaken as a Sub alliance with the Banora Point Upgrade Alliance (Roads and Maritime Services, NSW, Abigroup, Seymour White and SMEC).

Geotechnical conditions

  • Ground conditions consisted of extremely high strength basalt with UCS between 250 to 400 MPa. For about 50% of the piles, two layers of basalt had to be penetrated, with rock sockets up to 7m deep
  • Across the entire project Piling Contractors has drilled more than 1,000 linear metres of extremely high strength basalt (250-400 MPa UCS) using cluster drilling technology

Key Plant

  • Up to five drilling rigs (BG22, BG25, BG28) and two 110 ton crawler cranes on site, as well as a bentonite plant, cluster drills, dust extraction system and ancillary piling equipment.
  • The cluster barrel design and supporting stems were improved throughout the duration of the project based upon experience gained.
  • The peak equipment requirement was from September 2010 to March 2011.