Just after midnight on 14 November 2016, a 7.8 magnitude earthquake struck New Zealand’s South Island, roughly 60km south-west of the coastal town of Kaikoura.
The earthquake caused the ground to shift 8 metres horizontally and vertically by up to 3 metres, causing the South Island of New Zealand to move 6 metres closer to the North Island with ruptures occurring on 21 fault lines across 170km. This was the strongest ground acceleration ever recorded in New Zealand, causing significant damage throughout the upper South Island and even parts of Wellington, where the main Port suffered significant damage.
The earthquake required an immediate engineering response to rebuild damaged infrastructure in order to reconnect isolated communities and improve and future-proof the road and rail network. This all had to be done quickly but safely in a complex and highly sensitive environment.
In an industry first partnership, the New Zealand Transport Agency (NZTA) and KiwiRail came together to form an alliance with four of New Zealand’s largest contractors. Throughout the rebuild efforts, Aurecon has had their people leading the overall design services with teams in both the overall roading design programme and rail recovery programme.
The earthquake twisted train tracks and ruptured road pavements. Over 100 structures and 20 tunnels were damaged, with over one million cubic metres of rock and other debris coming down onto the road and rail links.
The Kaikoura township and surrounding communities were totally cut off due to the closing of State Highway 1, the Main North Line railway between Picton and Christchurch – the main road and rail routes into and out of the area.
Kaikoura’s harbour, where all the town’s whale watching boats are moored, also suffered after the sea bed rose up by a metre in the quake, inhibiting boats from entering or leaving the harbour, leading to a major downturn in the tourist economy for the region.
Their task was to quickly restore the road, rail and harbour infrastructure that are critical lifelines to the surrounding communities. With this in mind, the NCITR alliance committed early on to support the goal of reconnecting these communities by the end of 2017.
NZTA approached Aurecon in April 2017 for a design concept that would increase the safety, reliability and amenity for a 60km stretch of this challenging coastal route. In an effort to accelerate the development of solutions for inclusion in the rebuild, Aurecon fast tracked the options process and delivered a concept design including cost estimates, economic justification and consenting requirements within a six-week timeframe.
The team developed a detailed 3D digital InfraWorks model to work through the entire 60km route, testing various design solutions with the client in a real-time digital environment. The interactive nature of the 3D model really helped NZTA to see the situation from a different perspective, allowing them to move forward quickly with clear decisions.
“For the Clarence to Oaro concept design workshops, Aurecon had prepared large roll out plans spread across the tables, but it wasn’t until we switched to the screen to see the corridor in 3D that the practicality of options came to life. Being able to develop concepts “on the fly” and see the potential environmental impacts was invaluable in considering options. The 3D Digital Technology turned the concept into reality for the NZ Transport Agency Board and Executive Team, enabling them to clearly see the customer outcomes being delivered” says Michael Blyleven, System Design Manager, NZTA.
Delivering this work successfully ahead of schedule led to Aurecon Major Projects Director Tim Watterson being appointed by NCTIR to lead the overall design programme as Design Director, which now includes over 300 designers.
Project leader for the Kiwirail portion of the recovery programme, Aurecon’s Walter Rushbrook says, "Given the narrow transport corridor and the close proximity of the road and rail, it has been essential for teams to work closely with each other. We approached the rebuild task by sequencing work from either end, with the goal of meeting in the middle.”
The Main North Line railway, prior to the earthquake, provided passenger services and carried over 1 million tonnes of freight per year. To support the ambitious timeline to get this crucial transport network back up and running, Aurecon became the main provider of rail engineering services. From tunnel inspections and design to flood modelling and storm water design, Aurecon teams worked with NCTIR to deliver design concepts that would not only reconnect communities, but also protect this lifeline for them in the future.
One of the main challenges of the programme has been the fact that the affected road, rail and marine transport links are critical lifelines to the surrounding communities. Freight and passenger trains ground to a halt, whale and sea life watching tours were stranded in the marina due to the reduced water depth, and other tourism related businesses saw their income flown out of town with the evacuation of tourists from the area. With this in mind, the team committed early on to support the goal of reconnecting these communities by the end of 2017.
The critical Main North Line railway between Picton and Christchurch was re-opened less than a year after the earthquake, in early September 2017. While Kaikoura’s harbour was re-opened exactly one year after the earthquake on 14th November 2017, and the main coastal State Highway 1 link between Christchurch and Picton followed in December 2017.
The successful re-opening of the key transport routes and ongoing efforts to not only re-build, but also improve the safety and long-term resilience of the road and rail infrastructure, are testament to the hard work and collaboration of all the teams involved and the neighbouring communities.
"What we achieved in the space of a year is simply outstanding! Many people didn’t think we could do it. Everyone has worked extremely hard under challenging conditions. The level of personal commitment and teamwork across NCTIR has been quite humbling and a career highlight for many. It’s great to have re-connected communities and seeing first hand what this means for the region,” says Aurecon Major Projects Director, Tim Watterson.
The Main North Line Kaikoura Earthquake recovery project was awarded the Railway Technical Society of Australasia (RTSA) Biennial Project Award in 2018.