Geotechnical

Geotechnical investigations

Councils often require applications for resource or building consent to include a Geotechnical Report, often referred to as Geotech or Soil Report, to support a consent application. A Geotechnical Report provides an in-depth analysis of the type and strength of the soils present on the site using the Shear Vane Test and includes values and recommendations needed by the structural engineer, architect, and other professionals involved in the design and construction of the house or building. The soil investigation process involves the use of tools, commonly known as scala penetrometers and cone penetrometers, to supply details for the geotechnical reports. These reports offer insights into the soil composition and other information which forms the basis of the site inspections which will be completed at a later stage of the process. The geotechnical reports include the prospective architectural blueprints which are reviewed and integrated with the geotechnical scoping. This allows for a thorough evaluation of the risk factors involved in the construction process which is followed by recommendations for effective mitigation strategies to be discussed also in the reports. Soil compaction and other laboratory tests may be required to gain additional information about the soil.

Site stability assessments

If the site features a sloping ground (as a rule of thumb, a gradient of greater than 14 degrees is considered a criterion for a sloping ground), then it is necessary to conduct a slope analysis and issue a report as part of the building consent application process prior to the commencement of any earthworks or construction activities. It is important for the engineers to thoroughly analyze the conditions of the slopes as they are known to be associated with hazards which are to do with the long term safety of the properties concerned.

Groundwater monitoring

Shire provides groundwater monitoring. The groundwater assessment reports offer insights into the soil stability and we will determine the characteristics of the groundwater and how it might change over time.

Retaining walls

The construction of retaining walls for subdivisions, extensions, excavations, site stability, landscaping or other purposes requires careful designs and supervision by engineering specialists. Shire Engineering Consultants will undertake the site investigations to determine the soil conditions and site stability, and if necessary, the stormwater and groundwater modeling, to obtain the information for the retaining wall designs which we then use to propose effective solutions for the retaining walls with the aim to mitigate the risks involved in the projects.

Pre-purchase site inspections

During the construction phase, Council require a suitably qualified engineering professional to inspect various stages of the build and to ensure they meet building and other consent conditions. Shire Geotechnics are approved by various Councils around NZ to undertake this sign-off requirement.

Typically, Shire Geotechnics will have been involved in the site investigation and authoring of the geotechnical report, providing foundation and/or retaining wall design recommendations to the client and their structural engineer, architect, and planner (if engaged). During the construction phase, the results and recommendations in the geotechnical report will be used as the basis for the approvals.

Where another company has written the report, or their recommendations have led to problems on site, then Shire Geotechnics can be engaged to provide sign-off and recommendations to achieve consent. Once all works are completed to the satisfactory requirements, we will issue a Producer Statement (PS4) to Council on your behalf.

Other site-based and inspection services include:

  • Pre-purchase appraisals.
  • Building settlement.
  • Land stability
  • Earthworks
  • Retaining wall dilapidation survey

 

With more than 20 years’ experience conducting site inspections in Auckland and around New Zealand, you can count on Shire to get your development done right.

Does your project require a geotechnical report?

Get in touch with us to discuss your requirements.