Specialist Hydraulic Testing of Soil & Rock

Atlas Engineering and Technology Group provides comprehensive specialist hydraulic testing services for soil and rock materials from our Sydney-based, NATA-accredited laboratory. Understanding the hydraulic properties of ground materials is crucial for a wide range of geotechnical and environmental engineering projects. Our experienced team utilises advanced equipment to deliver accurate and reliable data, informing critical design and construction decisions.

Why is Hydraulic Testing Crucial?

The way water moves through soil and rock (its hydraulic conductivity or permeability) significantly impacts:

  • Foundation Design: Assessing settlement rates and potential for uplift pressures.
  • Slope Stability: Evaluating pore water pressure effects on shear strength.
  • Dewatering System Design: Determining inflow rates and dewatering requirements for excavations.
  • Pavement Design: Understanding subgrade drainage characteristics.
  • Retaining Wall Design: Assessing hydrostatic pressures.
  • Contaminant Transport: Modelling the movement of pollutants in groundwater.
  • Dam and Levee Design: Evaluating seepage rates and internal erosion potential.
  • Landfill Design: Assessing liner and cap performance.

Our Hydraulic Testing Capabilities

We offer a comprehensive suite of laboratory tests to determine the hydraulic properties of soils and rocks. Our key testing services include:

Permeability/Hydraulic Conductivity Tests

These tests directly measure the ease with which water flows through a soil or rock sample. Key methods include:

  • Constant Head Permeability Test (AS 1289.6.7.1): Primarily used for granular soils like sands and gravels, where flow is relatively rapid.
  • Falling Head Permeability Test (AS 1289.6.7.2): Suitable for fine-grained soils such as silts and clays, which have lower permeability.
  • Flexible Wall (Triaxial) Permeability Test (AS 1289.6.7.3): This test allows for permeability testing under specific confining pressures that simulate in-situ stress conditions. It is applicable to a wide range of soil types and provides a more realistic assessment of field hydraulic conductivity.

Consolidation Testing (AS 1289.6.6.1)

While primarily used to determine settlement characteristics, consolidation tests also provide vital data on hydraulic conductivity. The rate of consolidation is governed by how quickly pore water can escape the soil matrix. This test helps in understanding:

  • The coefficient of consolidation (\\(c_v\\)).
  • The coefficient of volume compressibility (\\(m_v\\)).
  • The indirect assessment of hydraulic conductivity (\\(k\\)).

Dispersibility Tests

These tests are crucial for assessing the susceptibility of clayey soils to erosion and dispersion when exposed to water, which can lead to failures in earth structures. We conduct:

  • Pinhole Dispersion Test (AS 1289.3.8.1): This test simulates water flowing through a small defect (pinhole) in a soil sample to observe dispersive erosion.
  • Emerson Class Number / Crumb Test (AS 1289.3.8.1): A simpler test that classifies the dispersibility of soil aggregates based on their reaction when immersed in water.

Specialist Large-Scale Permeability Tests

Standard laboratory permeability tests may not be representative for projects involving large aggregates, rockfill, or materials used in drainage layers. Atlas can perform or coordinate specialist large-scale permeability tests tailored to your project's specific materials and requirements.

Advanced Equipment & Quality Assurance

Our Sydney laboratory is equipped with state-of-the-art hydraulic testing apparatus. All testing is conducted by trained technicians in accordance with relevant Australian Standards (AS) and to the highest quality, underpinned by our NATA accreditation. This ensures that you receive precise and dependable results.

Applications & Projects

Our specialist hydraulic testing services are vital for:

  • Infrastructure projects (roads, railways, tunnels)
  • Residential and commercial developments
  • Mining operations
  • Landfill and waste management facilities
  • Water retaining structures