Site investigation is the process of gathering information about the ground conditions and environmental setting of a site. This information is used to inform the design and construction of new developments, and to assess the risks associated with existing sites.
On-site or in-situ testing is a key part of site investigation. In-situ tests are conducted directly on the ground, without the need to remove any soil or rock samples. This allows our engineers to obtain information about the ground conditions over a larger area, and to test the ground in its undisturbed state.
There are many different types of in-situ tests available, each with its own strengths and weaknesses, we explore them all here.
In-situ tests are used for a variety of purposes in site investigation, including:
- To identify and classify soil and rock types
- To assess the strength and bearing capacity of the ground
- To determine the compressibility and deformation properties of the ground
- To assess the risk of liquefaction
- To assess the risk of ground collapse
- To assess the risk of groundwater contamination
In-situ tests are a valuable tool for engineers and environmental consultants. They provide a rapid and cost-effective way to obtain information about the ground conditions at a site. This information is essential for the safe and efficient design and construction of new developments.
How on-site testing benefits you
In-situ testing offers benefits including:
- Reduced costs: in-situ tests can often be conducted more quickly and cheaply than traditional sampling and laboratory testing.
- Improved accuracy: on-site tests test the ground in its undisturbed state, which can provide more accurate results than laboratory tests on disturbed samples.
- Reduced risk: in-situ tests can help to identify potential risks associated with a site, such as the risk of liquefaction or ground collapse. This information can be used to design and construct new developments in a way that minimises these risks.
If you are planning a new development, or if you are concerned about the risks associated with an existing site, it is important to consider in-situ testing as part of your site investigation program.
Let’s dig into the on-site tests that we offer at Igne as part of our comprehensive site investigation services:
Cone Penetration Testing
What it is
Cone penetration testing (CPT) is an in-situ method used to determine the geotechnical engineering properties of soils and delineating soil stratigraphy. It is a rapid and cost-effective way to assess the subsurface conditions of a site, and is often used as part of an integrated ground investigation approach.
How does cone penetration testing work?
CPT involves pushing a cone-shaped penetrometer into the ground at a constant rate of 20 mm/s. The penetrometer is equipped with sensors to measure the cone tip resistance (qc), sleeve friction (fs), and pore water pressure (u) as it is pushed into the ground.
What data can be obtained from CPT?
The data obtained from CPT can be used to determine a wide range of geotechnical parameters, including:
- Soil type and stratigraphy
- Soil strength and stiffness
- Soil consolidation characteristics
- Soil permeability
- Liquefaction potential
- UXO risk
Why it is used
Benefits of CPT:
CPT offers a number of benefits over other ground investigation methods, including:
- It is a rapid and cost-effective method of subsurface exploration.
- It provides continuous data profiles, which can be used to develop detailed models of the subsurface conditions.
- It is a relatively non-invasive method, with minimal disturbance to the ground.
- It can be used in a wide range of ground conditions, including soft soils, sand, and clay.
Igne's CPT rigs are equipped with state-of-the-art equipment and operated by experienced and qualified personnel. Igne also offers a range of data analysis and interpretation services to help clients make the most of their CPT data.
Permeability testing is a method used to measure the rate at which water flows through a soil sample. It is an important test for geotechnical and geo-environmental investigations, as it can be used to assess a wide range of ground conditions, including:
- Soil type and stratigraphy
- Soil strength and stiffness
- Soil consolidation characteristics
- Soil permeability
- Liquefaction potential
What we offer
Igne offers a comprehensive range of permeability testing services, including:
- Constant head permeability testing
- Variable head permeability testing
- Slug permeability testing
If you are planning a geotechnical or geo-environmental investigation, contact Igne today to discuss your permeability testing requirements. Our experienced and qualified personnel can help you to develop a permeability testing plan that meets your specific needs and budget.
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Standard Penetration Testing (SPT)
Standard penetration testing (SPT) is a type of in-situ geotechnical test that is used to assess the relative density, bearing capacity, and settlement of granular soils. It can also be used to approximate the strength of cohesive soils, but it is important to note that this is not as accurate as other methods.
How does SPT work?
SPT is performed by driving a split-spoon sampler into the ground at the bottom of a borehole. The sampler is driven using a 63.5 kg (140 lb) hammer falling from a height of 760 mm (30 in). The number of blows required to drive the sampler the final 300 mm (12 in) is recorded as the SPT N-value.
What data can be obtained from SPT?
The SPT N-value can be used to determine a wide range of geotechnical parameters, including:
- Relative density of granular soils
- Bearing capacity of granular soils
- Settlement of granular soils
- Approximate strength of cohesive soils
SPT is widely used in a variety of geotechnical applications, including:
- Site investigation for foundations, roads, bridges, and other infrastructure projects
- Assessment of bearing capacity and settlement
- Liquefaction potential assessment
- Design of ground improvement schemes
Soakaway (Infiltration) Testing
Soakaway testing, also known as infiltration testing, is a method used to assess the suitability of a site for a soakaway. Soakaways are used to collect and dispose of rainwater or stormwater runoff by allowing it to infiltrate into the underlying soil.
Why is soakaway testing important?
Soakaway testing is important for reasons including:
- To ensure that the soakaway will be able to dispose of the anticipated volume of runoff. If the soakaway is too small, it will overflow and cause flooding.
- To ensure that the soakaway will not cause groundwater pollution. If the soil is too permeable, contaminants in the runoff may flow through the soil and contaminate groundwater.
- To ensure that the soakaway will not destabilize the ground. If the soil is too soft, the weight of the soakaway and the runoff may cause the ground to collapse.
How does soakaway testing work?
Soakaway testing involves excavating a trial pit and filling it with water. The rate at which the water infiltrates into the soil is measured and used to calculate the infiltration rate.
What data can be obtained from soakaway testing?
The data obtained from soakaway testing can be used to determine:
- The infiltration rate of the soil
- The size and depth of the soakaway required
- The risk of groundwater pollution
- The risk of ground instability
Light Weight Deflectometers
Igne offers on-site Light Weight Deflectometer (LWD) testing services to measure the bearing capacity and compaction quality of soils and unbound base layers. LWD testing is a non-destructive method that can be used to quickly and accurately assess the stiffness of a wide range of materials, including subgrade soils, base courses, and granular fills.
Applications of LWD testing include:
- Construction quality control: LWD testing can be used to ensure that soils and unbound base layers are compacted to the specified requirements.
- Pavement evaluation: LWD testing can be used to assess the condition of in-service pavements and identify areas that may need maintenance or repair.
- Geotechnical investigations: LWD testing can be used to characterize the bearing capacity and stiffness of soils for geotechnical design purposes.
California Bearing Ratio
California Bearing Ratio (CBR) testing is a penetration test used to evaluate the strength and bearing capacity of soil and subgrade materials. It is a critical test for designing and constructing roads, pavements, and other structures that support heavy traffic loads.
Igne offers on-site CBR testing services to help you get the most accurate and reliable results possible. Our experienced technicians will come to your site and perform the test using state-of-the-art equipment. We will then provide you with a detailed report of the results, which you can use to make informed decisions about your project.
Igne offers on-site down-hole shear vane (DHSV) testing services to measure the undrained shear strength of cohesive soils. DHSV testing is a direct push method that can be used to quickly and accurately assess the strength of a wide range of soils, including clays, silts, and peats.
Plate Load Testing
Igne offers on-site plate load testing services to measure the bearing capacity and deformation characteristics of soils and construction materials. Plate load testing is a direct push method that can be used to quickly and accurately assess the strength and stiffness of a wide range of materials.
Igne boasts a wide range of on-site geophysics services to help our clients understand the subsurface conditions at their project sites. Geophysics is a non-destructive method of investigating the subsurface using a variety of techniques, including electrical resistivity, ground penetrating radar, seismic refraction, and magnetometry.
Groundwater Quality Parameter Assessment
Igne hosts a range of on-site groundwater quality parameter assessment services to help our clients understand the chemical and physical properties of their groundwater resources. We can test for a wide range of parameters, including pH, electrical conductivity, total dissolved solids, major ions (e.g., sodium, chloride, calcium, magnesium), nutrients (e.g., nitrate, nitrite, phosphate), and metals (e.g., iron, arsenic, lead).
Igne’s on-site borehole instrumentation services to monitor a wide range of subsurface conditions, including groundwater levels, pore pressures, soil movements, and seismic activity.
We can install a variety of instruments in boreholes, including:
- Piezometers used to measure groundwater levels and pore pressures.
- Inclinometers used to measure soil movements.
- Seismometers used to measure seismic activity.
- Strainmeters used to measure ground deformation.
VOC/SVOC Detection and Monitoring
Igne offers on-site VOC/SVOC detection and monitoring services to help our clients identify, quantify, and track volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) in air, water, and soil. VOCs and SVOCs are a wide range of chemicals that can be harmful to human health and the environment.
Benefits of VOC/SVOC Detection and Monitoring Services:
- Early detection: VOC/SVOC detection and monitoring can help to identify potential problems early, before they cause serious harm to human health or the environment.
- Comprehensive analysis: We can detect and quantify a wide range of VOCs and SVOCs, providing you with a complete picture of the chemical composition of your samples.
- Accurate results: We use state-of-the-art equipment and experienced technicians to ensure accurate and reliable results.
Soil Thermal Resistivity
Soil thermal resistivity is a measure of how well soil resists the flow of heat. It is an important property to understand when designing and installing underground infrastructure, such as power cables, pipelines, and geothermal heating and cooling systems.
Electrical resistivity is a measure of how well a material resists the flow of electrical current. It is a property that can be used to map the subsurface and identify buried objects, geological structures, and groundwater aquifers.
From buried treasure to hidden hazards, the Earth's subsurface holds many secrets. Igne's down-the-hole magnetometer services can help you to uncover these secrets, providing you with a clear picture of what lies beneath your feet.
Igne’s down-the-hole magnetometers are specialised instruments that can be lowered into boreholes to measure the Earth's magnetic field. This information can be used to identify a wide range of objects and features, including:
- Buried ferrous objects, such as pipes, tanks, and drums
- Geological structures, such as faults and fractures
- Groundwater aquifers
- Unexploded ordnance (UXO)
Groundwater and Gas Monitoring
Groundwater and gas are essential resources that we rely on every day. But they can also be dangerous if not monitored properly. Igne's groundwater and gas monitoring services help you to keep an eye on the hidden world below your feet, ensuring that your water is safe to drink and your air is safe to breathe.
We offer a wide range of groundwater and gas monitoring services, including:
- Groundwater level monitoring: We monitor groundwater levels to track changes in groundwater storage and identify potential problems, such as overdraft or contamination.
- Groundwater quality monitoring: We test groundwater for a variety of contaminants, including bacteria, metals, and chemicals.
- Soil gas monitoring: We monitor soil gas for the presence of hazardous gases, such as methane, carbon dioxide, and radon.
Our groundwater and gas monitoring services are used by a variety of clients, including:
- Municipalities: We help municipalities to ensure that their drinking water supplies are safe and that their wastewater treatment systems are operating properly.
- Industrial facilities: Igne helps industrial facilities to comply with environmental regulations and to protect their workers from exposure to hazardous gases.
- Property developers: Igne assists property developers in assessing the environmental risks at their development sites and helps design and install mitigation measures.
Why is groundwater and gas monitoring important?
Groundwater and gas monitoring are important for reasons including:
- Public health protection: Groundwater and gas monitoring helps to protect public health by identifying and addressing potential contamination sources.
- Environmental protection: Groundwater and gas monitoring helps to protect the environment by identifying and addressing potential pollution sources.
- Economic protection: Groundwater and gas monitoring can help to save businesses money by identifying and addressing environmental problems early on.
Igne's groundwater and gas monitoring services can help you to:
- Protect your water supply: Igne can help you to ensure that your groundwater is safe to drink by monitoring water levels and quality.
- Protect your workers: Igne can help you to protect your workers from exposure to hazardous gases by monitoring soil gas levels.
- Comply with environmental regulations: Igne can help you to comply with environmental regulations by monitoring groundwater and soil gas levels.
Inclinometer and Extensometer Testing
Inclinometers are used to measure the tilt or inclination of structures and the surrounding soil. Extensometers are used to measure the movement of soil and structures. These instruments are used in a variety of applications, including:
Slope monitoring: Inclinometers and extensometers are used to monitor the stability of slopes and identify potential landslide risk.
Foundation monitoring: Inclinometers and extensometers are used to monitor the movement of foundations and identify potential settlement problems.
Dam monitoring: Inclinometers and extensometers are used to monitor the stability of dams and identify potential breaches.
Contact us today to learn more about our inclinometer and extensometer testing services and how we can help you.
The Earth is a complex and dynamic system, with layers of soil and rock that vary in density from place to place. Understanding the in-situ density of soil and rock is essential for a variety of applications, including geotechnical engineering, environmental assessments, and construction quality control.
Igne's in-situ density services provide you with accurate and reliable data on the density of soil and rock at your project site. We use a variety of state-of-the-art testing methods, including the sand replacement method, the nuclear density gauge method, and the cone penetration test method.
For more information regarding any of our On-Site Testing solutions, contact Igne today