Seabed Geotechnical Surveys

TDI-Brooks offers offshore, nearshore, and inland marine geotechnical survey services using a suite of innovative tools for soil sampling and measurement. We also provide a comprehensive set of geotechnical analytical services for characterizing offshore samples.

Our toolbox is designed for soil sampling and in‑situ measurements and includes box corers (BC), piston corers (PC), gravity corers (GC), jumbo piston corers (JPC), vibracorers (VC/pVC), a cyclic T‑bar instrument (TBAR), deep‑reaching Shelby tube samplers (SPLR), and piezocone penetrometers including our CPT‑Stinger and gravity CPT (gCPT) tools. Our vessels can also accommodate select third‑party geotechnical equipment packages. In addition to field operations, TDI‑Brooks provides soil testing through our in‑house geotechnical laboratory.

Our Geotechnical Toolkit provides high-quality soil samples and in-situ data from the following tools:

Geotechnical Toolkit (Highlights)

Download the Seabed Geotechnical Coring Operations Video HERE

Contact us with any questions: info@tdi-bi.com

Download the Auto T-Bar Flyer HERE

The TDI-Brooks Auto T-Bar instrument measures the progressive resistance of a soil column to a cylindrical rod (shaped as an upside-down T) as it advances down the soil column at a constant and standard rate of travel. The instrument is shown in Figure 9, with its T-bar protruding below.

In this figure, the pink trace represents the initial downward stroke of the T-bar into the soil. The two (right and left) nested sets of blue traces are the subsequent progressive upstroke and downstroke data, with the inner traces being the 30th and final stroke set. All measurements have been converted using an Nt-bar of 10.5 to represent undrained shear strength. This plot illustrates the progression of soil reworking toward fully remolded character during the course of the 30 sets of strokes. Such a data set can thus be also used to project fully remolded values at selected soil depths.

Download the Box Core Flyer HERE

The TDI-Brooks box coring system consists of hardware assemblies designed to be rigged together into a working core rig and deployed to the seabed for extracting a standard cubic box core. Such a core is 100-cm (depth) x 50-cm x50-cm or 50-cm (depth) x 50-cm x50-cm in size. The main winch, main coring rope, and the starboard A-Frame are used for deploying and retrieving the box core rig.

Our box coring system is designed to be a safe, simple, effective mechanism for acquiring large-volume undisturbed shallow sediment samples from the seabed. Such samples are essential for the accurate determination of geotechnical characteristics of marine sediments and the assessment of the benthic ecology (infauna) as required in environmental impact assessments.

The sample box of the core rig is fabricated from stainless steel and is clean and smooth to minimize frictional resistance between the box and the sediment. The corers have a variable weight capability so that the weight stack can be adjusted to suit different seabed conditions that may be encountered.

The CPT-Stinger is installed in a JPC core-head, deployed and triggered with the well-proven TDI-Brooks JPC process, and allowed to free-fall ballistically to insert itself into the sediment like a JPC. Once fully embedded in the seafloor with the necessary resulting reaction force now available, the CPT-Stinger is programmed to extend a rod from inside the barrel deeper into the formation (like a stinger) at the standard ASTM (static) cone push rate.

The CPT Stinger can be inserted to about 72 ft BML (while gathering dynamic CPT data), and then used to push a cone penetrometer to about 135 ft BML while gathering static CPT data. Because the extended rod is essentially as long as its barrel, in-situ CPT data can be acquired to sediment depths double of that of the barrel length of the tool (or of a corresponding JPC).’

Download the Dual Van Veen Grab Sampler Flyer HERE

The sampling device is composed of two 0.04 m² samplers (.08 m² total) joined together in a single frame. The target penetration depth is 0.1 m, which is the nominal limit of the grab sampler. One sample can be collected for benthic infauna (one side of the grab) and the 2nd side of the grab for geotechnical measurements at each site. A grab sample is deemed successful when the grab unit is > 75% full (with no major slumping). The grab sampler is recovered from the seabed and back onto the vessel at a velocity which minimized any potential loss or disturbance to the seabed sample.

Download the Ferritech FT550 Vibrocorer Flyer HERE

Feritech’s vibrocorer is one of the most versatile on the market, with its modular construction, high power variable frequency, sensor capabilities, and software control.

The 3rd generation FT550 lightweight variable frequency high power vibrocorer leads the market in its technical innovation and performance.

Product Highlights:
Variable frequency of 5 – 50Hz

The subsea equipment is built to withstand the harsh offshore environment and unforgiving handling. The topside software informs the engineer of the information he needs to ensure efficient, successful and safe deployment and operation. Due to its simple-to-assemble modular construction, the system can be mobilized very quickly for cores of 1-12m.

Variable frequency and thrust Feritech Global’s vibrocorer is the only system on the market with an integrated high power varible frequency system. By using this unique variable frequency system, sample disturbance is minimised, ensuring a high quality sample regardless of high power settings.

Unlike any other vibrocorer system, the Feritech vibrocorer can be deployed and recovered to deck in the horizontal or vertical axis, meaning that the user can choose the best deployment and recovery method for the vessel they are operating from. The quick release barrel system ensures a fast barrel change optimising operational equipment time. A barrel can be changed in a matter of minutes, whether the system is being deployed in horizontal or vertical mode

With its modular construction, the entire FT550 system and spares can easily be packed into a standard 20 foot ISO shipping container.

The sensors measure in 3 dimensions and so can detect a target both in front of and to the side of the barrel.

The topside controller shows the engineer the information he needs to ensure an efficient, successful and safe deployment and operation. The rugged topscreen unit displaying and logging real time data from the system for the user, including:

TDI-Brooks offers offshore, nearshore, and inland marine geotechnical survey services using a suite of innovative tools for soil sampling and measurement, including box corers (BC), piston corers (PC), gravity corers (GC) and jumbo piston corers (JPC).

We have the following portable geotechnical took kits for use on a 3rd party vessel:

Contact us with any questions: info@tdi-bi.com

Download the gCPT Flyer HERE

The purpose of the TDI-Brooks Gravity CPT (gCPT) tool is to transport a precisely calibrated memory cone penetrometer down to the seabed/lakebed to gather dynamic PCPT cone data from the mud line to 10+ m BML. In addition to its 1,800 lb (800 kg) driving head with lifting bale and trigger, the rig comprises a self-contained PCPT cone penetrometer that measures tip resistance (qc), sleeve friction (fs), and pore pressure (u2) using standard ASTM dimensions and protocols for its 15 cm² cone.

The TDI-Brooks jumbo piston coring (JPC) system consists of various hardware assemblies designed to be fastened together into a working core rig and deployed to the seabed for extracting a “jumbo” piston core. The deployed core rig comprises assemblies for the core head, the core barrel, the piston, and the trigger system. The JPC rig can be assembled to collect a sample up to 64 feet long. There is also lifting assembly that attaches to the trigger system, allowing the system to be deployed with an A-frame. The core barrel assembly is made up of selected sections of core barrel, connecting collars, a core liner assembly inside the barrel assembly, a core catcher, a core cutter, and set screws to hold the barrel assembly together. The inner diameter of the core liner is 4 inches. The barrel length can be adjusted in 5-foot and 10-foot increments by adding barrel sections and connecting collars. The trigger assembly is made up of the trigger arm, pendant clamp, trigger weight, trigger wire, and trigger wire connecting system. The assembled core rig weighs between 5,500 and 7,000 lbs, depending on the length of core to be acquired. The weight of the core head is adjusted by adding weight as lead ingots to a starting weight of about 5,000 lb.

The main winch, main-line rope, and the stern A-Frame are used for deploying and retrieving the JPC rig. In addition to the deployed hardware, several assemblies are mounted to the vessel working deck to manage the deployment and retrieval of the coring rig. These assemblies include the main sheave from the stern A-Frame and the deployment, retrieval and trigger tugger winches with their hydraulic power pack.

Download the Manta-200 CPT Flyer HERE

The TDI-Brooks’ Manta-200 Cone Penetration Testing (CPT) system is suitable for almost any project in shallow water up to 150 meters. The CPT system is powered by a unique Continuous Drive System (CDS) that was designed with a clear focus on durability and high production. It also guarantees uninterrupted penetration of the cone.

The Manta-200 CPT system is a modular design capable of delivering results on even the most challenging of projects with a chain-drive based system that can reach penetration depths of up to eighty meters. Both casings and tubes can be operated simultaneously.

During CPT operation the Manta is controlled from the surface with a real time link over a combined power and communication umbilical. Data can be viewed in real time allowing operators to manage the push and react to local sediment conditions to provide the highest quality data to the greatest depths possible.

The Manta system is composed of the base equipment which is then completed with supporting options like ballasts and winches all depending on your project’s requirement. The heart of each system is its capability of retrieving and processing high quality data. During CPT operation the Manta is controlled from the surface with the control box. The controls are intuitive and easy to use. Data is viewed in real time as with a conventional CPT. Data, communication and power are all handled by the umbilical.

The Manta-200 measures 2,200 x 2,200 x 2,300 mm(L x W x H) when being transported. The basic setup is transportable in 20 ft sea containers.

MSCL systems rapidly and non-destructively obtain high-resolution (typically 1 cm to 10 cm downcore spacing) geophysical and geochemical data from sediment and rock cores. The high quality multi-parameter stratigraphy delivered from MSCL systems enables facies classification and soil/rock typing ahead of, or in support of a visual description. Ultimately this leads to improved laboratory test planning for any necessary destructive or advanced laboratory testing. The Geotek core logging services team follows strict calibration procedures for each core size and liner type to ensure consistency and accuracy of data collection.

Sediment or rock cores with or without metal or plastic liners up to 1.5 m long and 155 mm in diameter can be accepted. Physical, elemental and mineralogical properties can be obtained from whole or split/slabbed core samples regardless of whether they are within a liner or not. An MSCL dataset provides vital information about core heterogeneity or homogeneity ahead of destructive laboratory testing or visual logging.

More details here: TDI-Brooks Partners With Geotek UK to Deliver Expanded Services – TDI-Brooks International (tdi-bi.com)

Download the Neptune 5K CPT Flyer HERE

The Neptune 5000 Heavy Duty CPT System is a coiled rod Cone Penetration Test System featuring a 35kN Push capability with a coiled tubing CPT system that is easy to mobilize.

The system has a maximum penetration of 20 meters with real time control and data acquisition and built-in automatic safety cut-outs making it perfect for the renewables market.

This highly advanced equipment is designed for thrusting 5 cm² or 10 cm² Digital Cones. The unit can thrust up to a maximum of 70 MPa and has a depth rating of 3000 meters. This is an excellent tool for investigating seabed conditions prior to seabed installations such as pipelines, power cables and underwater constructions. The measurements comprise of penetration depths, cone resistance, sleeve friction, pore pressure and inclination from vertical.

The system can be mobilised to a variety of vessels depending upon the nature of the project, ranging from the fuel efficient vessels at 30m LOA, to regular charter vessels upwards of 50-70m LOA. The high mobility and small footprint of 2.2m x 2.2m makes it perfect to be mobilized onboard vessels of opportunity.

The 5000 is fitted with 5cm or 10cm Digital Piezocones and benefits from self-tuning telemetry. The surface controls unit operates a Microsoft Windows PC combined with the established Neptune software package, providing real-time data.

Download the Neptune 3K CPT Flyer HERE

The TDI-Brooks Datem Neptune 3000 Miniature Coiled Rod CPT System is a coiled rod Cone Penetration Test System featuring a 10kN Push capability. This lightweight coiled rod CPT system is for use in up to 3000 meters of water and designed to withstand the harshest of sea environments.

A coiled tubing CPT system that is easy to mobilize, featured coiled rod system enables the Neptune 3000 to be self-contained and compact, therefore allowing the system to be deployed from the smallest of survey vessels where space is often of a premium. This CPT unit is commonly used for pipeline surveys for oil and gas operators and cable route surveys for offshore renewables.

The Neptune 3000 CPT enables its operators to perform an in-situ real-time test of the subsea soil structure therefore eliminating/reducing the requirement for time intensive soil sample extraction, storage and examination, thus reducing project duration and therefore cost.

The system uses Datem’s digital 2cm cones, 5cm cones and T-Bar cones to suit all subsea soil conditions, providing axial load, sleeve friction, pore pressure, dual axis tilt and temperature data in real time (selectable up to 20hz) as they penetrate through the soil with data comparable to that of 10cm cones. With a push force of up to 10kN and a maximum push distance of 10 meters the Neptune 3000 is an industry renowned and hugely popular CPT system globally.

Download the Piston Corer Flyer HERE

The TDI-Brooks 3-inch-diameter (3-in.) piston coring system consists of various hardware assemblies designed to be fastened together into a working core rig and deployed to the seabed for extracting a piston core. The PC rig can be assembled to collect samples up to 30 feet long and collects a 3 inches diameter sample. The deployed core rig comprises assemblies for the core head, the core barrel, the piston, and the trigger system. The core head assembly is made up of a lead-weighted core head with nosepiece and a coupling with which to attach lengths of core barrel sections. It also has a lifting flange assembly that attaches to the trigger system. The trigger assembly is made up of the trigger arm, pendant clamp, trigger weight, trigger wire, and trigger wire connecting system. The core barrel assembly is made up of selected lengths of core barrel sections, connecting collars, a core liner inside the barrel assembly, a core catcher, a core cutter, and set screws to hold the barrel assembly together. The barrel length can be adjusted in 5-foot increments by adding 5 or 10-ft barrel sections and connecting collars.

The main winch, main-line coring rope, and the starboard A-Frame are used for deploying and retrieving the 3-in. piston core rig. In addition to the deployed hardware, several assemblies are mounted to the vessel working deck to manage the deployment and retrieval of the coring rig. These assemblies include the main sheave from the starboard A-Frame and the core-head and trigger tugger winches with their hydraulic power pack.

Download the Pneumatic Vibracorer Corer (pVC) Flyer HERE

The TDI-Brooks Pneumatic Vibracorer (pVC) is a lightweight high power vibracorer. The pVC can be used for cores of 1 to 6 meters (and down to 12-m with frame extension). The topside display informs the winchman of the exact penetration of the core barrel into the soil at any point during its vibrating insertion.

Vibracorer Technology

Vibracoring is a technique for collecting core samples of seabed sediments and wetland soils. The core barrel is incrementally driven into sediment aided by gravity, using an asymmetric pulsing energy imparted to the barrel from the vibrating head. These pulses are generated by a pneumatic pressure drop across the head, which produces mechanical pulses (hammer blows) in the downward direction at a 10-20 Hz rate. The pulses cause a thin layer of material to mobilize along the outer barrel wall and the inner core liner wall, reducing friction, easing penetration into the substrate, and aiding recovery of the soil material into the liner.

Although vibracoring is not a system for hard material, like drilling, it has become the industry standard for the collection of environmental and sedimentological samples in shallow marine depositional environments. This is partly due to the efficiency of vibracoring – with cores up to 6 meters retrievable in 10 minutes, but also due to the high recovery of vibrated samples. In loose soils, recovered core lengths can approach full barrel penetration depth. In stiffer soils, less than half penetration depth is recovered from less than full penetration, as the liner plugs with soil and stops the movement of the core material up the liner. For marine environmental studies – particularly where chemistry is needed, the higher recovery of sediments is critical in understanding the history of the deposited sediments. The down-side of vibrating soil material to achieve greater core recovery is that the sample collected will likely geotechnically disturbed.

Pneumatic Vibracorer Origins

Some of the earliest designed vibracorers came from the construction industry using impact hammers and vibratory motors to run pile drivers. Early versions were frequently driven mechanically and as techniques progressed and adapted to the marine environment the approach migrated to air driven systems. This offered more flexibility and mechanical simplicity for usage underwater and allowed operation from more mobile, smaller vessels. The downsides being water depth limitations due to hose constraints and loudness both on the boat and in the water.

The subsea equipment is built to withstand the harsh offshore environment and unforgiving handling. It is designed for safe deployments and retrievals using a robust process from the stern of the vessel. Operations are safely conducted by a winchman, an a-frame operator, and two deckmen. Due to its simple-to-assemble modular construction, the system can be mobilized very quickly for cores of 1-6-m.

TDI-Brooks has a Geotek XCT system on campus to acquire both 2D X-ray transmission images and 3D X-ray CT volumes from lined whole core, split core, or slabbed core sections. Automated rotation of lined core sections allows users to visualise and record three-dimensional structures within the cores. These rotational images are used for computed tomographic (CT) reconstructions. X-ray CT imaging provides valuable quantitative data as well as information about core quality for sub-sampling or further analyses. More details here: TDI-Brooks Partners With Geotek UK to Deliver Expanded Services – TDI-Brooks International (tdi-bi.com)