Challenges arose from a combination of site conditions: excess topsoil, water-adverse material (Alluvium) and prolonged periods of wet weather. These factors impacted the suitability of materials for re-use according to the original geotechnical reports, the overall balance of onsite cut/fill, and the ongoing accessibility for construction. This resulted in lodgement of multiple challenging contractor variations.
Other challenges included:
- Requirement for additional scope of works, such as external sewer and electrical infrastructure upgrades.
- Poor weather and difficulty in completing construction resulted in an extension to duration of works.
As Superintendent, Orion’s role was:
- Defining the extent of variations and sorting them into manageable and measurable stages of work. The contractor prioritised immediate site access as part of the construction approach. Consequently, the project was divided into multiple stages, leading to several variations. Orion’s task was to outline necessary inclusions and the cost for each variation
- Assessing and communicating the contract rates. Allowing the contractor to proceed with onsite works during favourable weather, bypassing delays caused by uncertainties such as ground condition investigations and price variation.
- Ensuring the geotechnical advice was followed by monitoring construction activity and inspecting issues on site.
- Verifying the contractor’s submitted quantities through a first-principles assessment using onsite test pits and a detailed breakdown of quantities street by street and area by area. This process promptly ensured the integrity of the Bill of Quantities (BOQ), preventing the inclusion of both the original contract quantities and additional rates intended to cover the entire process of win, load, haul, spread, compact, and testing operations.
