On geotechnical investigation sites, technical staff often mention the term SPT rig. Many people mistake it for a specific drill model, but this is wrong. Today, we’ll take a close look at this key equipment system widely used in geotechnical testing.
What Is SPT?
First, we need to figure out what SPT stands for. The full name of SPT is Standard Penetration Test, a globally popular in-situ test method. Simply put, a 63.5-kilogram drop weight falls freely from a height of 76 centimeters to drive a standard penetration sampler into soil. Workers record the blow count needed to push the sampler 30 centimeters down, known as the N-value. A higher N-value means denser soil and higher bearing capacity. Apart from identifying soil properties, this test also collects undisturbed soil samples for lab testing.
Technical Specifications of SPT Rig
Below are key specs for selected models of the YG series hydraulic core drilling machine ( Click to view product details). All these models work perfectly as ideal base machines for the SPT rig.
| Model | YGX-400 | YGX-600 | YGX-800 | YGX-1000 |
| Drilling Depth(M) | 180-400-500 | 200-600-650 | 400-800-1000 | 500-1000-1100 |
| Rated pressure(MPA) | 21 | 21 | 25 | 28 |
| Rated Flow(L/min) | 168 | 192 | 260 | 300 |
| Heat Dissipation Mode | Air cooling+water cooling | |||
| Engine Brand | Yuchai | Yuchai | Yuchai | Cummins |
| Rated power/speed | 78kW/ 2400r/min | 92kW/ 2400r/min | 92kW/ 2400r/min | 154kW/2400r/min |
| Drilling Angle(°) | 0-90 | 45-90 | 45-90 | 45-90 |
| Lifting Force(T) | 12 | 16 | 24 | 30 |
| Feed Force(T) | 6 | 8 | 12 | 15 |
| Hydraulic Mud pump flow | 30-90（L/min） | 30-90（L/min） | 90-180（L/min） | 90-180（L/min） |
| Hydraulic Mud pump power | 4-7(MPA) | 4-7(MPA) | 4-7(MPA) | 4-7(MPA) |
| Dimension | 4000*1900*1800mm | 4000*2000*1800mm | 5500*2100*2000mm | 6000*2200*2400mm |
| Weight | 4.3T | 4.5/5.5T | 6.5T | 7.5T |
What Is an SPT Drill Rig?
Strictly speaking, the commonly referred spt rig is not one fixed drill type. It refers to geotechnical exploration drills fully fitted with complete Standard Penetration Test accessories. A complete spt drill rig consists of three essential parts: an automatic hammer lifting system, a standard split-tube penetration sampler, and high-stiffness sounding rods. Ordinary core drills can be upgraded into SPT rigs once these parts are installed. The automatic drop hammer system is its core component: powered by the drill’s engine, mechanical parts lift the hammer precisely to 76cm before releasing it. This keeps a consistent standard of striking energy and eliminates errors caused by manual rope pulling.
What is a Hydraulic Core Drilling Machine?
A hydraulic core drilling machine is modern drilling equipment driven by hydraulic motors and cylinders, mainly used for core sampling in medium-to-deep boreholes through rock formations. Its standout features include stepless speed regulation and integrated mast-chassis design. Take the YG series as an example: these drills adopt a tracked chassis with a remote control and telescopic mast, so no extra derrick setup is required for transport and assembly. Operators can accurately adjust rotating speed and feed pressure during drilling. Matched with thin-wall diamond wireline coring technology, users pull core barrels out via inner steel wire without repeatedly tripping drill pipes, greatly boosting construction efficiency.
How Do SPT and Hydraulic Core Drilling Machine Work as a Powerful Combination?
In real geotechnical investigation projects, ground layers usually feature soft topsoil over hard bedrock. Within one single borehole, the spt rig switches between two tasks: run SPT tests on shallow overburden to collect N-values and soil samples, then shift to diamond wireline coring mode for deep hard bedrock drilling. Thanks to this dual-purpose design, the full-hydraulic spt drilling machine becomes the top-choice exploration equipment for foundation works of high-rise buildings, bridges, dams, and other large-scale infrastructure.
Four Major Advantages of Full-Hydraulic Drills for SPT Operations
- Fast tripping: Full-hydraulic winches deliver strong lifting power and quick response to run penetration samplers and drill pipes in and out of boreholes, cutting down non-drilling downtime greatly.
- Thorough hole cleaning: Precisely controllable rotary speed of hydraulic power head and mud pump flow clear cuttings at the hole bottom thoroughly, preventing debris from distorting SPT N-value test results.
- Standardized hammer drop: Modern full-hydraulic exploration drills come with factory-fitted automatic drop hammer systems, maintaining an exact 76cm drop height to make all SPT data comply with international standards.
- Easy site relocation: Remote-controlled tracked chassis plus integrated mast design occupy small ground space with no foundation needed, enabling fast setup and shifting of test boreholes for multi-point field testing.
Application Fields of SPT Rig
A reliable SPT rig is never just lab equipment; it plays an irreplaceable role in three core engineering sectors:
- High-rise and super high-rise buildings: Calculation of foundation bearing capacity relies on precise SPT-N values. The spt drill rig detects compactness of each soil layer to provide reliable data for pile foundation design.
- Bridge and tunnel projects: Bridge abutments and tunnel portals often sit atop thick sand and cobble layers. The spt drilling machine, equipped with an automatic drop hammer, efficiently assesses soil liquefaction risk and surrounding rock classification.
- Airport runways and port reclamation zones: Large-area artificial fill requires fast multi-point in-situ testing. Tracked full-hydraulic drills move flexibly across construction sites like off-road vehicles to arrange test holes quickly.
Take Action Now: Pick the Right SPT Rig for Your Project. Want detailed model lists, quotations, and SPT automatic hammer configurations of the YG series hydraulic core drilling machine? Contact us to get the latest technical parameters and real-site construction cases.
