2110 Trinity Stage 31 Civil Works

Trinity Estate development: Trinity Stage 31 Civil Works subdivision project

  • Client:

    LWP Property Group

  • Location:

    Alkimos WA

  • Construction Period:

    Aug 15 – Jan 16

  • Key Elements:

    • Project management
    • Civil construction
    • Subdivision construction
    • Earthworks
    • Remediation
    • Clearing
    • Demolition
    • Underground services
    • Sewer reticulation
    • Stormwater installation
    • Water main installation
    • Roadworks
    • Concrete
    • Client Liaison

Project overview

Following on directly from the successful completion of the previous stage of the Trinity Estate development, Northern Corridor Development Ltd (LWP) awarded DM Civil the Trinity Stage 31 Civil Works subdivision project.

The work under contract involved the placement of 14,000 cubic metres of imported fill for the northern batter (future stages) and 2.0 kilometres of retaining walls and noise walls. Underground services consisted of 750 metres of sewer reticulation, 970 metres of stormwater drainage, 1.3 kilometres of water reticulation, 3.7 kilometres of underground power cables and 2.2 kilometres of telecommunications pipe and pit. This was covered by 11,500 square metres of roadworks, including both asphalt and brick pavements, 4.1 kilometres of kerbing and 3,500 square metres of footpaths. These elements produced a development of 63 residential lots.

As with the previous contract for Stage 30 earthworks and civil works and Stage 31 earthworks, the construction programme was critical which required some overlapping tasks for the 2 contracts.

DM Civil was able to negotiate the award of this project due to the timely and successful completion of the previous stage.

Significant achievements and benefits

Remaining on site from the previous stage gave DM Civil the opportunity to negotiate an early start on the rock excavation in deep trenches using trenching rock saws. This allowed improvements on the efficiency of the sewer and stormwater drainage aspects of the project and provided zone C backfill material from the trench spoil.

Due to the significant area of the work site, dust control was a major concern. DM Civil formulated and followed a detailed dust management plan which included a full time water cart fed from a rapid fill overhead water tank with the application of Dustex stabilising agent on days with a forecast for high winds. The site was progressively hydro-mulch stabilised as earthworks were completed and in high risk areas. Wind fencing to the perimeter of the work site ensured further containment of dust nuisance from the existing surrounding residents.

In line with the previous stages, DM Civil continued to strive to accommodate the client’s requests to carry out miscellaneous minor works outside of the original scope of the contract. This included construction of an additional carpark for the nearby sale office, stormwater infiltration improvements to two public open spaces, numerous footpath piece-ups and repairs, and installation of new fencing at various locations.

Using the experience gained from the previous stages, DM Civil site staff were able to foresee potential constructability problems, thereby increasing efficiencies and creating savings for the client. The Client expressed his appreciation of the proactive approach to efficiency and the willingness of site management to accommodate additional and nonstandard tasks. Many of the additional tasks were outstanding works not completed on previous contracts.

DM Civil and LWP together with GHD, the superintendent, formed a strong project team that was committed to the completion of what was a large body of work within programme.

Download the 2110 Trinity Stage 31 Civil Works project report