Geotechnical Engineering Team

EI’s in-house geotechnical team specialises in assessing geotechnical risk to property and infrastructure development.

The team is experienced in dealing with a broad range of challenging geotechnical projects, including land instability, deep excavations in soil and rock, groundwater control, adverse foundation and subgrade conditions.

Range of Geotechnical Services

EI provide Geotechnical Engineering services and professional support in the following areas:

  • Site investigation and reporting
  • Lot classification in accordance with AS2870-2011 for shallow footing design
  • Foundation design and excavation shoring design
  • Pavement assessment and earthworks design
  • Slope stability and rock face stability studies
  • Groundwater infiltration and groundwater management
  • Geotechnical/ geological hazard and terrain assessment
  • Salinity, thermal resistivity, durability Assessments
  • Vibration, settlement & noise monitoring
  • Construction QA/QC services
  • Construction aggregate, quarry and borrow studies.

Geotechnical Investigations

The objective of an intrusive geotechnical site investigation is to establish the subsurface conditions for a proposed development to aid in the civil and structural design, or for Development Application (DA) purposes.

Each site investigation is specifically designed to suit the client’s requirements and incorporates appropriate investigation techniques for the anticipated, site-specific geology and hydrogeology.

Field investigation findings and laboratory test results are analysed and used to create a Geological and/or Geotechnical Site Model, which is applied to the overall assessment of the site.

Soil design parameters are then developed for commercial and residential buildings, roadways, bridges, utilities and sewage lagoons. EI carries out preliminary and detailed Geotechnical Investigations in accordance with AS1726 1993 Geotechnical Site Investigations.

Foundation Design

EI can provide foundation designs which are cost effective and robust for developments from single-storey residential homes to multi-storey buildings with infrastructure.

Examples of foundation options for sites with shallow stable ground conditions, include: Pads; Rafts; and Piled Rafts. Examples of foundation options for sites with deeper stable ground conditions, include: Bores piers; CFA piles; Screwed piles; and Driven piles.

Slope Stability

EI’s Geotechnical Team includes trained and certified RMS (RTA) Slope Risk Assessors, with experience in the AGS Slope Risk Assessment methodology and international experience.

After detailed site inspection EI is able to conduct computer analysis capable of assessing sloping ground. Remediating slopes that may fail or have already failed forms an area of specialist in-house expertise.

We can additionally provide advice on the monitoring of ground deformation such as the potential movement on deep retaining structures.

  • Some remedial measures that EI’s geotechnical team cane advise on include the use of:
  • Soil nails;
  • Shotcrete facing;
  • Dentition;
  • Buttressing;
  • Slope regrading; and
  • Shoring and retaining structure input.

Shoring & Retention Systems

EI are regularly involved in projects with basement structures, which require retaining structures to shore the excavations. We have experience in providing design options for retaining structures in excavations, including:

  • Reinforced concrete cantilever walls;
  • Contiguous and secant pile walls with or without anchors;
  • Jet grout options;
  • Post and plank;
  • Gravity walls – gabions, cribwalls etc.;
  • Reinforced Earth /Soil Structures (RSS);
  • Diaphragm Walls and Shafts; and
  • Steel sheet pile walls.

Pavement Design

Pavement analyses and design is often carried out for the construction of new roads within new residential and industrial subdivisions; which may include, roundabouts, car parks, industrial hard stand areas and bus stops. These may include flexible and rigid (concrete) pavements.

EI can carry out pavement evaluation on existing pavements for assessment of road, pavement material and subgrade conditions and for the design of asphalt overlay.

Our experienced, professional team provide options, when applicable, for new pavement configurations, making it possible for you to select a design that is economical and practical for your purpose.

ACTION: Get EI’s Geotechnical Engineering Capability Statement – Download PDF

geotechnical investigation

Geotechnical investigation as part of foundation design assessment


Shrinkage crack in residual Clay overlying Ashfield Shale formation

deep excavation

Deep excavation works with concrete sheet piled site

piling rig

Piling rig in action on urban development site


Inclinometer assessment