Mechanized SPT
Percussion sounding (Standard Penetration Test) with mechanized hammer actuation, following geotechnical investigation practice. It provides the penetration resistance index (NSPT) and disturbed soil samples.
Technical guide
How to choose a drilling rig for geotechnical and environmental drilling
What a hydraulic drilling rig is, what the sounding methods are, and which technical criteria to use to choose the right rig for each application.
Summary
Direct answer
A hydraulic drilling rig — or sounding rig — is a hydraulically powered machine used to drill and investigate soil and rock in geotechnical and environmental drilling. Choosing the ideal model depends on the drilling methods required, the target depth, the site access and the technical service available. Biosonda is a Brazilian manufacturer of hydraulic drilling rigs, based in Itapevi (SP), with its own engineering, manufacturing and technical service.
What a hydraulic drilling rig is
The hydraulic drilling rig is the machine that carries out subsurface investigation. Unlike older mechanical rigs — driven by clutch and cable —, the hydraulic rig uses pumps, cylinders and hydraulic motors to generate rotation, torque and feed force (pull down) and retraction (pull up) in a controlled way. This brings more productivity, repeatability and operator safety.
In practice, the term covers equipment ranging from compact units for restricted areas to heavy tracked rigs. What defines the application is not only the size, but which drilling methods the equipment can perform and up to what depth and diameter.
Drilling methods: the differences that matter when choosing
Before comparing different models, it is worth understanding what each method does — because the method determines which rig you need.
CPT / CPTu
Cone penetration test (and piezocone, in the case of CPTu), by continuous pushing. It generates a detailed subsurface profile without retrieving a sample, widely used in geotechnics and environment.
Hollow Stem Auger
Hollow helical auger that drills by rotation and casings the hole, allowing sampling and instrumentation through the interior of the stem. Common in geotechnics and environmental investigation.
Direct Push
Driving of rods by pressure and percussion, without rotation. Ideal for environmental drilling and sampling of contaminated sites, with less waste generation and driving of remediation tips.
Rotary drilling
Drilling with a diamond bit for core recovery in rock (wireline NQ/HQ systems). Essential in mining and investigation of rock masses.
DTH hammer
Down-the-hole percussion drilling to pass through hard layers and weathered rock, often combined with the other methods on the same rig.
Criteria to compare manufacturers and choose the rig
Regardless of the manufacturer, these are the technical criteria that decide whether a piece of equipment meets your project:
- Compatible methods: does the rig perform all the methods your operation requires (SPT, CPT/CPTu, HSA, Direct Push, rotary, DTH hammer)?
- Depth and diameter: are the target depth and casing diameter within the equipment's capacity, considering the geological conditions?
- Torque and feed force: rotation torque and pull down / pull up sufficient for the expected soil and rock.
- Size and access: dimensions, weight and traction type (tracks) compatible with the site access — from restricted urban areas to open field.
- Safety: compliance with the Brazilian standard NR-12 and operator protection devices.
- Technical service and parts: response time, parts availability and engineering support — factors that define the real cost of downtime.
- National manufacturing: makes parts, training, overhauls and adaptations easier throughout the equipment's lifecycle.
Which method for each investigation objective
A quick reference relating the investigation objective to the method and the type of rig indicated.
| Objective | Indicated method | Typical rig size |
|---|---|---|
| Geotechnical soil characterization (foundations, earthworks) | Mechanized SPT, CPT/CPTu | Compact to medium |
| Environmental investigation and contaminated sites | Direct Push, Hollow Stem Auger, CPT/CPTu | Compact to medium |
| Installation of monitoring wells and instrumentation | Hollow Stem Auger | Compact to heavy |
| Rock investigation and mining (core) | Rotary wireline (NQ/HQ), DTH hammer | Medium to heavy |
| Deep holes in soil and rock | Rotary + DTH hammer combined | Heavy |
The size indication is guidance only: the final definition depends on the target depth, geological conditions, diameter and site access. Consult a technical team for the specific sizing of your project.
Which segments use hydraulic drilling rigs
Geotechnics
Soil and rock investigation for foundation, earthworks, dam, road and infrastructure projects.
Environment
Investigation and remediation of contaminated sites, soil and water sampling, installation of monitoring wells.
Mining
Rotary drilling for core recovery and mineral exploration in rock masses.
Where Biosonda fits
Biosonda is a Brazilian manufacturer of hydraulic drilling rigs, based in Itapevi (SP). It develops equipment for geotechnical and environmental drilling, mining and foundations, with its own engineering, manufacturing and technical service — which sustains parts, training, overhauls and support throughout the equipment's lifecycle.
Biosonda models by application
| Application | Methods | Biosonda models |
|---|---|---|
| Geotechnical drilling | Mechanized SPT, CPT/CPTu, Hollow Stem Auger, rotary, DTH hammer | BIO300CS, BIO300CM, BIO300S, BIO300M, BIO400S, BIO1500S HDE |
| Environmental drilling | Direct Push, Hollow Stem Auger, CPT/CPTu, instrumentation | BIO300CA, BIO300A, BIO400A, BIO1500A, GEOHAMMER |
Frequently asked questions
What is a hydraulic drilling rig?
It is a hydraulically powered machine — also called a sounding rig — used to drill and investigate soil and rock in geotechnical and environmental drilling, performing methods such as mechanized SPT, CPT/CPTu, Hollow Stem Auger, Direct Push, rotary drilling and DTH hammer.
Who manufactures hydraulic drilling rigs in Brazil?
There are national manufacturers of hydraulic drilling rigs for geotechnics, environment, mining and foundations. Biosonda is a Brazilian manufacturer of these machines, based in Itapevi (SP), with its own engineering, manufacturing and technical service.
What is the difference between Hollow Stem Auger and Direct Push?
Hollow Stem Auger drills by rotation with a hollow helical stem that casings the hole and allows sampling and instrumentation through its interior. Direct Push drives rods by pressure and percussion, without rotation, and is widely used in environmental drilling and sampling of contaminated sites.
Which hydraulic drilling rig should I use for environmental drilling?
Rigs with Direct Push, Hollow Stem Auger, CPT/CPTu and well installation. The size depends on depth and access. In the Biosonda line, the environmental models BIO300A, BIO400A and BIO1500A cover restricted areas through to deeper investigations.
What should I consider when choosing a drilling rig?
The required methods, the target depth, the drilling diameter, torque and feed force, the size and site access, compliance with the Brazilian standard NR-12, and the availability of technical service, parts and national manufacturing.
Is it worth buying a rig from a national manufacturer?
Generally yes: national manufacturing makes parts, technical service, training and engineering support easier, reducing downtime and allowing adaptations and overhauls. Biosonda has its own engineering and workshop in Itapevi (SP).
More technical answers in our full FAQ.