GEOTECHNICAL SERVICES
This is a brief overview of our geotechnical services.
RESIDENTIAL & COMMERCIAL BUILDING & SUBDIVISIONAL SITE INVESTIGATIONS
Fundamental to our operations has been our ability to take on and complete thousands of site investigations for developments ranging from individual building sites, to large multi-lot subdivisions, for end uses ranging from simple residential dwellings, through commercial/industrial buildings, and onto high-rise buildings.
We co-operatively work alongside developers, surveyors, civil and structural engineers, architects, draughts people, contractors, and Councils to progress builds from ideas to plans, to Resource/Building consents, to construction and to completion.
GEOTECHNICAL GEOMORPHOLOGICAL APPRAISALS & SLOPE STABILITY ANALYSES
Critical to the development of any land, is getting to grips with its hazards and risks - especially when so much of the ‘easy’ land has been developed, leaving the more marginal ground.
At WJ we use dynamic on-the-ground assessments such as geomorphological mapping to interpret and understand changes in the ground over time, and then combine that model with up-to date numerical analyses to assess how those hazards and risks might change in the future under recognised influences.
EARTHWORKS SUPERVISION & CONTROL
Breaking in land, especially those larger tracts, requires a high level of ability and experience across a wide range of skills. WJ staff have had many, many years of experience monitoring and certifying large and small scale subdivisional earthworks. In fact, it has been one of our founding services, one which we continue to relish.
RETAINING WALL DESIGNS
When developing land, especially when it is economically marginal, it is not uncommon to need some form of appropriate retaining wall.
Retaining walls we design include:
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Simple timber pole and plank, all the way up to complex, often high, reinforced concrete walls designed using WALLAP analysis.
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Gravity walls such as gabions or mass concrete blocks.
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Soil nailing to reinforce the slope/ wall with a series of soil-nails implanted deep into the ground.
SETTLEMENT ANALYSES
Settlement analyses, whether for simple load cases using our in-house spreadsheets or for more complex systems using the software Settle-3D, can allow us to predict future settlement patterns or back-analyse past settlement failures when a building has settled and distorted, allowing the design and installation of appropriate preventative or restorative measures.
GROUND IMPROVEMENT
When land is identified as vulnerable to some form of settlement, such as liquefaction induced by earthquakes or consolidation of soft compressible soils, we have current and evidence-based solutions to improve the land for building development.
CLASSIFICATION OF EXPANSIVE SOILS
Identifying expansive soils before designing building foundations is crucial to ensure the correct precautions and foundations are utilised for a sturdy and safe building.
WJ have been leading adopters and reporters on expansive soils since the early days of AS2870 being introduced to New Zealand. We not only have developed our own field equipment to allow us to sample and test soils in a manner that fits with AS2870 systems, but we can also sample and test in accordance with the legacy New Zealand methods if appropriate.
ON-SITE STORMWATER & EFFLUENT DISPOSAL
If you’re developing in rural areas with little or no council provided reticulation services, then you are likely to have to utilise some form of on-site disposal for both stormwater and effluent. WJ has years of investigation and design experience in both types of disposal.
We also have extensive experience with urban stormwater disposal via shallow soak-pits and/ or retention tanks, or deep rock-bore disposal in those city areas where basalt rock has made stormwater reticulation too expensive, resulting in homeowners having to dispose of their roof and pavement stormwater run-off into on-site disposal systems.
GEO-FORENSICS & EXPERT EVIDENCE
If you haven’t made use of our services, and something has gone wrong, as they sometimes do, then you need reliable independent objective advice based on thorough review and analyses, which we commit to provide.