Christchurch City Council Engaged Fulton Hogan to undertake a number of projects to upgrade services and roading along Riccarton Road including a major upgrade of the wastewater network. Riccarton Road is a significant through route in Christchurch, as such a key objective was to ensure minimal disruption to traffic and stakeholders.

Martin Civil Construction’s role in the work was to increase the capacity of the wastewater network to reduce wet weather surcharges and provide new, resilient wastewater infrastructure assets between Matipo and Harakeke Street.

Martin Civil Construction, subcontracted to Fulton Hogan undertook

• • Installation of DN500 PVC-U SN16 wastewater main pipes in 3-4m trench
  • Installation of DN375 PVC-U SN16 wastewater main pipes in 2-3m and 3-4m trench
  • Installation of sanitary sewer wastewater collectors (225 PVC SN 16)
  • Installation of 1200mm square and circular manholes, 4m and 6m sheet piles and trench shields
  • Installation of a 400mm and 900mm Raft under pipes and Manholes
  • Installation of sanitary sewer laterals
  • Support of services crossing the trench
  • CCTV, Ovality and pressure testing of DN 500 and DN 375 pipelines, including hydrostatic testing of the DN500 line
  • Removal of existing pipes and relay with new DN150 PVC-U SN16 and connect into existing lines and into new manholes
  • Grouting of existing redundant earthenware pipelines

Key challenges

• • Trench depth breached water table requiring 24 hour dewatering of trenches and regular sediment/contaminant testing alongside control measures
  • Limited work spaces in some areas requiring careful project planning to ensure most efficient use of space
  • Limited access to site at some areas for side street connections