In Situ Site Investigation is able to provide a wide range of CPT rigs to meet our clients’ requirements and specifications. In addition to our rigs, we also have our own transport for moving our rigs around the country. This enables us to have full control over our moves and better serve our clients. Click here for all our CPT rig data sheets.
DIGITAL PIEZO STATIC CONE PENETROMETER
The Digital Piezo Static Cone Penetrometer (PCPT) is a rugged and compact system; the analogue to digital conversion is performed down hole, with each cone possessing its own memory and identity that is automatically recognised when connected to the logging system.
This is a compression cone, meaning the tip resistance and sleeve friction load cells are decoupled and measure independently; this ensures that the readings from the cone are more accurate than other cones. Accurate temperature compensation assures reliable performance in soft soils and also in a situation where there is a considerable difference between air temperature and ground temperature.
A dissipation test is used to calculate consolidation parameters such as the coefficient of consolidation in cohesive layers. The test is carried out by stopping penetration in cohesive layers where the cone has generated an excess pore pressure. During the pause in penetration, any excess pore pressure generated around the cone will start to dissipate. The rate of dissipation depends upon the coefficient of consolidation, which in turn, depends on the compressibility and permeability of the soil.
We then measure the time it takes for this excess pore pressure to drop back down to the hydrostatic pore pressure. The rate of this dissipation allows us to calculate the coefficient of consolidation.
The Gamma Cone measures variations in naturally occurring gamma radiation. The gamma sensor is mounted behind a standard CPT cone allowing us to obtain standard geotechnical data as well as gamma radiation simultaneously.
This probe is commonly used for chalk solution feature investigations. It can be hard to tell the difference between clay infill material and highly weathered chalk due to its similar properties when the cone is pushed through. By using the gamma cone, we would obtain high gamma readings in the clay material due to the presence of elements such as potassium and very low readings in the chalk. Using this probe in conjunction with other parameters such as pore pressure allows us to accurately determine the chalk interface.
SEISMIC CPT CONE
The seismic piezocone (SCPTU) is a probe that combines standard CPT along with geophones to measure seismic velocity within the ground. The cone can be configured to measure s and p waves. The seismic cone is used to measure the seismic velocity of the ground from sources that are based at the surface. The measurements taken can be used for analysis of small strain stiffnesses of the ground.
INTRUSIVE MAGNETOMETER SYSTEM
The Intrusive Magnetometer System is used to survey for UXB (unexploded bombs) across a range of environments including, Rivers (and Riverbanks), Land, Harbours, Railways, Tidal and Near Shore Marine.
The probe is highly sensitive three-component Fluxgate Magnetometer System which can be deployed from a variety of platforms. The system has high detection capabilities, which in most environments has the ability to detect a 50kg WWII bomb at 2 metres from the probe. Surveys can be conducted to the maximum bomb penetration depth with high survey productivity rate.
The Computerised Intrusive Magnetometer Survey allows for the real time control of survey data with excellent data quality and is CAD compatible.
We also have a number of combined magnetometers that we use to combine both the magnetometer readings for ferrous objects and the cone penetration testing (CPT for geotechnical parameters). The advantage of this is that you use a single probe to carry out a single push for two activities.
During the use of our Magnetometer and combined Magnetometer and CPT cones, our operators are fully trained to identify potential abnormalities in the readings during testing. When a UXO clearance report is required, we will engage with a third-party specialist UXO company to provide this.
VIDEO CONE PENETROMETER
The Video Cone Penetrometer has a miniature colour video camera, an LED light source, micro-optic components, and a durable scratch-resistance sapphire window integrated into a Digital Piezo Static Cone Penetrometer (PCPT) cone housing. This single cone will provide standard geotechnical measurements, such as tip resistance and sleeve friction, as well a high-resolution view of the soil in real time.
The video image is displayed on a portable display screen and recorded digitally onto a DVD or hard disk. A text inserter module allows the video of the test to be stamped with the depth as it increases as well as the test identification number. Post processing provides a picture log which is imposed next to the PCPT log, helping with the correlation of the soil type.
The Video Cone is a useful tool in both Contamination Detection and Soil Classification. For environmental work, the Video Cone allows the visual detection or confirmation of the presence of non-aqueous phase liquid contaminants in the soil, such as creosote, tar and gasoline. For Geotechnical work, the Video Cone shows soil texture, grain size, colour and other soil features.