If you are developing your site, a Geotechnical Report or soils report may be required by Council as part of the Resource Consent or Building Consent process. This Council requirement is usually due to the site being affected, or potentially affected, by some sort of ground hazard. It may be a stability issue if the site is on sloping ground, or it may be due to the presence, or possible presence, of soft layers, fill or expansive soils. In these cases the Council may request that you engage a Chartered Professional Geotechnical Engineer to conduct a specific site investigation and prepare a geotechnical report.
Specific Site Investigation
The purpose of a specific site investigation is to confirm the ground conditions beneath the site and to identify any problems that may be associated with the stability of the site or the subsoils with respect to the proposed development. This will usually involve the drilling of boreholes or the digging of test pits with samples and testing carried out in-situ.
The Geotechnical Report will present the findings of the site investigation and recommend the most appropriate foundations and any stabilising measures, retaining walls, etc for the specific
Investigations by a Geotechnical Engineer would address for practicalities of site develop-ment associated with use of the land. This is to ensure the security of the development with time. The geotechnical investigations could include; slope stability issues, foundation requirements and disposal options for stormwater and wastewater.
Design and Construction
The stability and foundation issues identified during the Geotechnical Investigation may require specific design. This is likely to involve site drainage, retaining walls and specifically designed foundations. A Geotechnical Engineer would com-plete this work ensuring compliance with Council requirements. They would also give regard to the financial and architectural con-straints of the project. Inspections during the construction of the development would confirm design limits.
Development must also follow Council Building controls. A Registered Surveyor can set out the building location, and provide certif cation, to meet Building control requirements.
Sophisticated building developments and construction on difficult sites are possible given the appropriate level of participation from design professionals.