Christchurch Northern Corridor Downstream (CNC) Package 1

Overview

The purpose of this project was to upgrade and prepare Cranford Street and Sherborne Street (together with some adjoining side streets and key intersections) for the opening of the new northern motorway and subsequent increase in traffic volumes onto this road network in the district of St Albans in Christchurch.

The scope of the project included laying a new main watermain from just south of Berwick Street all the way to Bealey Avenue in the south including some lateral mains, together with significant drainage works at key road intersections, new kerb and channel on multiple sites as well as new upgrades for traffic signals and equipment at all three main road intersections of Berwick, Edgeware and Bealey. In addition, other less busy intersections on Madras Street and Barbadoes Street were to be altered and upgraded involving extensive drainage and kerb and channel rebuilds. Finally, a large area of the work site was to have full deep level road reconstruction for Carriageway upgrade, whilst other areas of roading would be extensively resurfaced before line marking.

Isaac Construction was the overall head contractor on this project and delivered all the civil works with the assistance of a small number of specialist key subcontactors.

This was designated one of the most important and high-profile projects for the Christchurch City Council due to its potential heavy impact on densely populated urban areas and its proximity to the central city. Negative traffic impacts from the many work sites and dozens of specific traffic management plans required had the potential, if not carefully planned and monitored. Strong Stakeholder Communications and a full-time resource were identified early on as being a key. The Isaac’s team were proud to be selected and chosen to deliver this key project.

The overall, essentially linear work site stretched nearly 2 kilometres from Westminster Street, crossing Cranford in the north all the way south and including the Bealey Avenue intersection with Sherborne Street. The large site was broken into 8 large work areas or Separable Portions. The first part of the job commencing in January 2020, involved extensive surveying and pot-holing exploration on multiple areas spread over many sites.

Excavation and removal of existing kerb and channel was quickly followed by the installation of new stormwater sumps with connections to new stormwater soak pits, new watermain and gas lines. Sewer laterals were installed concurrently which included the commissioning of new sewer and flush tank manholes. New kerb and channel pours, trenching for security ducting, and low voltage power supply, was completed prior to the laying of asphalt for new footpaths. Tens of thousands of square metres of new asphalt road surface along Cranford Street, Sherborne Street and at the main road intersections would be a highly visible and large part of the overall project. Decorative planted garden beds finished with mulch complete with street furniture, new signage and line marking added the finishing touches to the Canon Street and Purchas Street upgrades.

Works at most road intersections encompassed, stormwater drainage structures and mainlines, kerb and channel, newly asphalted footpaths and some roading speed bumps. On the entire project we calculate that more than 15,000m² of new asphalt was laid.

Challenges

Stakeholder Communications

Due to the sensitivity of roadworks taking place in a densely populated urban area, strong and effective communication with key stakeholders, businesses and residents was identified early on as being a key component to the success of the project. Each stakeholder had varied requirements and their concerns were quite different. A one size fits all approach to stakeholder management was not going to provide a satisfactory approach to managing this aspect of the project. Balancing the requirements of each stakeholder and their safety, whilst completing disruptive road works directly outside businesses and residential properties was a challenging component to the overall project which involved careful, detailed planning and consideration.

To ensure stakeholder requirements were met, extra resource and responsibilities were quickly allocated. A full time senior Communications Manager was allocated to the project, who worked closely and on a daily basis with the rest of the project team.

Covid – 19 Response

Some weeks into the project, a completely unforeseen event heavily impacted on this and many other construction projects around New Zealand. The global pandemic, known as Covid-19 was spreading and NZ was forced into a country-wide lockdown due to the virulent pandemic. Clearly this provided an unplanned for distraction and added a further layer of difficulty and complexity to the project.

The project team, together with guidance from the client decided that due to the unknown nature of the lockdown, particularly the time duration, to disestablish wherever possible from the overall site. This involved the swift and efficient transport of a number of large items of plant, up to 16 crews comprising 3-4 staff each along with all subcontractor crews, each having a mixture of large and small plant with varying transportation needs. All this had to be achieved within a little over 72 hours notice period, provided by the national government

Focus shifted quickly from laying watermain and drainage, building roads and installing footpaths to filling holes, installing fences and construction of temporary footpaths, in order to leave more than a dozen major work sites safe for the general public to be around. Within a 24-hour period, machinery including excavators, loaders, rollers, plate compactors etc were transported from site to be safely stored at the Isaac yard. During the next 24 hours, staff completed site safety measures to ensure the site would be left secure and safe for the public for the duration of the lockdown period. Additional fencing was hired, and special signage was produced and installed on each individual work site at short notice.

During lockdown, site safety and traffic management checks were completed twice daily, and planning meetings were undertaken via video calling applications.

Interaction with Other Contractors

For the duration of the project, the construction of certain elements of our programme necessitated a close working relationship with other main contractors who had been allocated different but adjoining areas of the overall CNC downstream project. Isaac Construction worked closely with other Contractors when planning works to ensure traffic management planning was optimal and there was a minimal impact on certain neighbourhoods and residents. Several joint planning meetings were held between main contractors to make each aware of the others planning and operations. Work programmes and sequences were adjusted to better fit one another’s time frames. The two main contractors were able to dovetail works well together and maintained a healthy, cooperative and fully professional working relationship throughout.