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Shaping the standard, shaping the land with Sally Hargraves

Engineering geologist Sally Hargraves discusses her role on the first revision in over 30 years of NZS 4431:2022 Engineered fill construction for lightweight structures.

Sally Hargraves, Engineering geologist and P4431 committee member

Sally Hargraves, Engineering geologist and P4431 committee member

P4431 committee member Sally, who hails from the United Kingdom’s picturesque and hilly Lancashire, brings a distinct perspective for ‘the small guys’, the independent small local consultants and contractors looking after rural and provincial needs in land development.

Knowing the geology

‘New Zealand has a unique geography and is quite different to the United Kingdom,’ Sally says. ‘It’s rare to build on greenfield sites in the United Kingdom – “greenfield” being a rural and usually protected green belt around urban areas. With brownfields, which act as a buffer between urban and rural areas, and built environments you could be building on several historic layers of foundation or metres of previously used material. New Zealand has much younger and more active geology, with faults and volcanoes and associated stability issues. It’s more “slopey” and “slippy”, and having a distinct New Zealand standard reflects that.’

The rural voice

‘Most of my time in New Zealand has been spent in Tauranga and Nelson,’ Sally says. ‘I like working in the provinces, where there is more freedom to be a generalist. As a local resource, you get to do a bit of every job, rather than being pigeon-holed into one specific area of expertise.

‘In the provinces, you don’t have the visiting lecturers, universities, and nearby networks to call upon. Having exposure to committee networks helps keep you connected professionally and is easily done online, forcing you to be a little more proactive with your upskilling.

‘Working in the provinces provides a unique viewpoint, as I’m dealing with small residential and rural sites and projects. There aren’t the big facilities or infrastructure like in the metropolitan areas. Representing this viewpoint on the committee makes sure the rural voice can be heard, which is so necessary for a country that still has large, isolated areas with small communities.’

Ready to act in times of need

‘In May 2005, a big weather bomb saw record levels of rain fall, with up to 148 mm in some areas, causing mass flooding and major slips and landslides across the Bay of Plenty. That was fun,’ says Sally wryly. ‘I had set up my own business just a month before this happened. There were hundreds of properties impacted and needing repairs to slips.

‘I was also able to help the Earthquake Commission (EQC) in Wellington after the 2016 Kaikoura quake, helping to assess and advise on damage, mostly to retaining walls. While these events are devastating, they do provide invaluable experience that informs your professional growth and learnings for the revision of standards.’

Shaping the standard

‘It’s quite a feeling to have an impact on a standard that you use in your daily work. For 4431, I’ve had input right through from the practical application of doing the drawings to advising on how land is developed and monitored. This update has also changed the structure of the standard substantially, separating off process and procedures from the specification side of things. We also wanted to include commentary boxes so we could show our thinking and include some guidance.

‘I think my main contribution was making sure the voice of small earthworks and provincial contractors was heard. From a practical point of view, there was discussion around how much detail to require, with some committee members suggesting detailed and precise survey measurements for fill extents and testing locations. I countered that this wouldn’t be practical or cost efficient for small or remote properties and the standard needed to be applicable to all New Zealanders’ properties, big or small.

‘Through the consensus approach, it’s important to listen to everyone. It allows for robust discussions considering multiple viewpoints and helps prevent biases so you can create one source of truth. For example, I remember a win when someone in the South Island suggested all volcanic soils be termed “difficult” or “unworkable” as fill materials. I countered that I’d been involved with numerous successful earthworks projects in volcanic soils and, because many parts of New Zealand are located on volcanic soils, saying otherwise could seriously hinder development in those areas.

‘The standardisation process helps to resolve differences. With limited viewpoints and opinions, decision makers may ignore agreed good practices and this could influence decision making. Without a standard, an authority could set its own criteria around what’s appropriate, without the agreement of the industry or sector.’

Get involved

‘I’ve been a rep on various committees for over 20 years. I was on the local Engineering New Zealand committee for several years and followed that up by being the New Zealand Geotechnical Society (NZGS) rep for Tauranga for several more years. I’ve helped organise a couple of symposia and more recently served on the NZGS Committee for six or seven years. I guess I’ve been helping out for most of my career and when I stopped doing the local rep role to raise a family, I realised I missed being involved.

‘So why do it? Building your professional network through being on committees or helping out with standard revisions means I stay in touch with the latest updates and advice in the industry. As a self-employed professional, I do give up my time to help out, whereas larger companies can perhaps more easily afford to let staff attend as part of their professional development. However, I find it worthwhile as it helps me keep connected with others at the forefront of the geotechnical world.

‘My recommendation would be that if you are using a standard on a day-to-day basis, then consider getting involved. You have a vested interest in it being done properly. You want to make sure it’s the best it possibly can be, as it will inform the way you and your peers work for many years ahead.’

The work of Sally and those on the P4431 committee can be seen in the latest revision of NZS 4431:2022 – Engineered fill construction for lightweight structures, sponsored for free download by the Building Systems Performance.