Comment Contractor

The contractor’s new best friend

A milestone was reached in the civil-construction industry last year when contractors and consulting engineers held a joint annual conference – mutual recognition of being members of the same team striving for the same goal. In the light of this welcome détente, GAVIN RILEY takes a look at the life of one consulting engineer.

ENGINEERING GEOLOGIST and geotechnical engineer Georg Winkler isn’t certain when contractors and consultants started working together more closely but he thinks it may date back just a couple of years and be due largely to the Christchurch rebuild.

While others might also credit project alliances for the new-found teamwork, Georg says the cost and urgency of the southern-city rebuild has placed heavy emphasis on “constructability”, which by definition requires contractors and consultants to work collaboratively to achieve the most cost-effective result.

A view of a slope underlain by a reasonably large landslide that threatened the house below it. Deep soil anchors were designed and installed by LDE to stabilise the slope.
A view of a slope underlain by a reasonably large landslide that threatened the house below it. Deep soil anchors were designed and installed by LDE to stabilise the slope.

He says it’s easy for a consulting engineer to recommend foundation designs in accordance with government guidelines, but sometimes the cost can be sky-high and a better solution has to be found – often with the help of the contractor. And not just in Christchurch.

“We do a lot of retaining walls and landslide repairs around the Far North, Wairoa and Gisborne and we try to get contractors to cast their eye over constructability matters, because they’re the people who know how easy or how hard it is to construct things,” Georg says.

“We know things they might not see straight away, like this little section of road is actually on a huge landslide, or that little retaining wall has to hold up that huge landslide. It’s about understanding costs.”

Georg Winkler is in his mid-40s and has headed his own consultancy for the past 10 years. Raised in Wairoa, he did a double major degree in geology and physical geography at Victoria University in Wellington and a master’s degree in engineering geology at Canterbury University.

After he had worked for environmental and engineering consultants Tonkin & Taylor in Auckland for 10 years, he and his wife decided in early 2004 it was time for a change. They moved to Gisborne where Georg set up Land Development & Exploration Ltd (LDE) as a small specialist company making use of his background in complex engineering technology and offering geological, geotechnical, civil, structural and environmental engineering services throughout New Zealand.

Georg misses Auckland for its big-city buzz and concerts, “but I definitely don’t miss the traffic”.

“We set up in Gisborne for a lifestyle change, and for the sunshine of course. The principle or mantra of the company is to allow people to live where they want to live and still do cool, interesting and challenging work. It’s working really well.”

So well, in fact, that LDE now has 30 staff and offices in Gisborne, Warkworth, Whangarei and Napier, and a presence in Christchurch.

Georg sees no drawback to having a Gisborne-based head office in terms of providing services. “We have a spread of qualified people on the ground around the country who do the testing. Where it’s tricky and requires a more senior person’s or specialist’s eyes, we fly people in. Because our overheads are low by having a Gisborne head office, flying senior guys in is still cost-effective.”

So is using Skype constantly for communicating. “We have meetings with four or five people all at once in all the different offices. They might as well be in the office right next to each other, because that’s how good it is.”

A large anchored retaining wall under construction in Northland. The retained height is actually 6m, although most of the wall structure is beneath the ground surface.
A large anchored retaining wall under construction in Northland. The retained height is actually 6m, although most of the wall structure is beneath the ground surface.

A tonne of work – in fact, many tonnes – came LDE’s way last July when severe rainfall in the Far North produced flooding and massive landslides on SH1 and the only detour road, closing Northland to heavy traffic and costing millions of dollars. The complex underlying geology saw Georg in his element.

“All contractors in Auckland who deal with earthworks will know of a group of rocks called Onerahi Chaos,” he says, referring to a sheared mudstone which is particularly prone to land movement. “That’s what I focused on in my master’s thesis.”

Nearly 400 slips had affected the roading network and LDE undertook a triage assessment of ranking the landslides based on their severity and consequences to the network. Because much of the Far North has the problematic Onerahi Chaos underneath it, the landslides were waiting to happen, Georg says.

“The situation was dire. I was standing on the detour road and a logging truck went over it and before our eyes the whole road moved sideways, due to unstable ground beneath the road and the vibrations and loads of heavy traffic.”

SH1 was closed for about two weeks. Some of the landslides are several hundred metres wide and caused massive damage. LDE carried out investigation and design of remedial measures for about 60 of the worst-case slips and had nearly completed this work at year’s end.

“There are some huge retaining walls, up to 11 metres high, with construction costs of $500,000 to $700,00 for one or two of them. There are all types of remedial solutions – there’s no one standard fix. Everything needs to be carefully considered and weighed up.”

Limited Transport Agency (NZTA) funding means the cheapest option is to repair the road surface at low cost. But because heavy rain in the future will cause the slips to occur again, LDE has been striving to produce solutions within the agency’s budget which are cost-effective.

In the Christchurch rebuild, under subcontract to Tonkin & Taylor, LDE has been carrying out modelling beneath suburbs affected by liquefaction and lateral spreading, and mapping the extent of lateral spreading throughout the city and Kaiapoi.

“We had a team tracking cracks through properties to work out how far back from the river the land had moved. It had moved much farther than anyone imagined,” Georg says.

“The good thing about that was the experience we got in co-ordinating a team of up to nine people in getting that information into a database. We applied that work to the Far North and helped the Far North District Council and NZTA to assess the actual cost of the [flooding and landslip] damage.”

Georg says repairs are still not completed following Gisborne’s 6.7 earthquake in 2007, and that long time-frame leads him to believe LDE will be involved in the Christchurch rebuild for a number of years yet.

A large-scale, deep-seated landslide that severed access to a small community north of Gisborne. LDE was involved with assessing the stability of the landslide and the design of a new road across it. Rising sea levels, increasing storm surges and rainfall from extreme weather events appear to have caused the landslide.
A large-scale, deep-seated landslide that severed access to a small community north of Gisborne. LDE was involved with assessing the stability of the landslide and the design of a new road across it. Rising sea levels, increasing storm surges and rainfall from extreme weather events appear to have caused the landslide.

With global warming producing erratic weather patterns and rising sea levels, he also foresees his company gaining work opportunities arising from major landslides and in coastal engineering.

“We do quite a few coastal structures. That [work] will continue to grow and contractors will be interested in that. Some of the projects are quite tricky. Sea levels rose about 15cm last century and you have increased storm events. Rising sea levels are eating away at the coasts and a lot of our roads in this country go round the coastline.

“Also, the sea level rising will raise the groundwater table in low-lying cities and towns. It will affect places like Napier, a lot of which is built on ground close to sea level and the groundwater table is already quite high.

“Another 15 to 20cm of rising sea level will raise the groundwater table close to the foundations of buildings, making all those areas much more prone to liquefaction and lateral spreading.”

LDE’s only problem is attracting sufficient highly qualified staff to be able to expand to capture current and anticipated future work. But Georg says that with the Australian mining boom over, Kiwi engineers are returning home. Added to that, he has succeeded in recruiting two English, two Irish and two German staff “and they’re all exceptional”.

So he’s looking forward to the future – and he thinks contractors should be too because of new technology and construction techniques on offer.

“The advance in construction methodology is really interesting. It’s exciting for contractors. There’s a lot of interesting new techniques being used in other parts of the world which contractors might like to have a look at for themselves and import and use.”

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