Why Are There So Many Kinds of CPT Rigs?

As you look through our website, you'll see that there are a number of different types of CPT Rigs. As you can imagine, they each have their purpose, or 'application'. In order to understand why different types of CPT Rigs exist, it's helpful to remember how CPT works in the first place. Cone Penetration Testing The goal of Cone Penetration Testing is to drive a hardened cone vertically into the the ground and to keep it moving at a specific rate of progress. The force that it takes to maintain the cone moving downward at a defined rate is an indicator of how hard the soil is at a given depth. The friction the cone sleeve encounters along the way gives us an indication of the make up of the soil. Deciding Between CPT Rigs As you can imagine, as the cone progresses further downward and encounters different types of soils, sands, clays and rocks it can take a substantial amount of pressure to keep it moving! One of the first factors that influences the design of CPT Rigs is the maximum amount of pressure that will be required to perform a specific test, to a specific depth in a given geological area. As much as 20 tons of downward force may be required to perform a broad enough range of tests to make a given rig viable for a market. For every ton of downward pressure on the test cone through the rod system, you have to have a reaction force equal to this to keep the Rig from lifting up. This means that either the Rig has to be heavier than the maximum push force, plus a safety margin, or it needs to be anchored down in some way as to reliably resist the upward force generated by [...]

The Importance of Proper Soil Quality

Sometimes it's hard to imagine how important designing the proper foundation support for a structure can be. The public may assume that the ground we are standing on is pretty much stable and should be able to hold whatever we build on it, without consideration of soil quality. However, there are examples throughout history of structures that were built upon soil conditions that were not suitable for their weight. Perhaps the most famous is the Leaning Tower of Pisa. With better soil quality, it may have been known today as the Tower of Pisa Unfortunately for the constructors, the Tower was built upon a patch of soil that was too soft on one side for the pressure the structure would exert as it's height climbed. The Tower actually had begun leaning during the construction process and had quite a tilt before it was even completed. Over time, builders began to realize that in order to build magnificent structures, and to have them endure over time, they had to understand the geology they were building on. They had to be able to translate an understanding of the soil quality that is not able to be seen into foundation designs that would support even the tallest skyscrapers we build today. Through lots of experimentation, science, engineering and creative solutions, we've been able to evolve our understanding of how to perform a variety of soil tests and how to link that to solid design and construction methods that will support structures as varied as highway bridges and high-rise buildings. As you explore the resources that we've provided in our CPT University, you'll learn about a variety of soil tests and the advantages of each. Tests such as Standard Penetration Tests (SPT), Cone Penetration Tests (CPT) and other forms of testing all have their [...]

Why Are There So Many Kinds of CPT Rigs?

As you look through our website, you'll see that there are a number of different types of CPT Rigs. As you can imagine, they each have their purpose, or 'application'. In order to understand why different types of CPT Rigs exist, it's helpful to remember how CPT works in the first place. The goal of Cone Penetration Testing is to drive a hardened cone vertically into the the ground and to keep it moving at a specific rate of progress. The force that it takes to maintain the cone moving downward at a defined rate is an indicator of how hard the soil is at a given depth. The friction the cone sleeve encounters along the way gives us an indication of the make up of the soil. As you can imagine, as the cone progresses further downward and encounters different types of soils, sands, clays and rocks it can take a substantial amount of pressure to keep it moving! One of the first factors that influences the design of CPT Rigs is the maximum amount of pressure that will be required to perform a specific test, to a specific depth in a given geological area. As much as 20 tons of downward force may be required to perform a broad enough range of tests to make a given rig viable for a market. For every ton of downward pressure on the test cone through the rod system, you have to have a reaction force equal to this to keep the Rig from lifting up. This means that either the Rig has to be heavier than the maximum push force, plus a safety margin, or it needs to be anchored down in some way as to reliably resist the upward force generated by the test (or 'sounding'). Depending upon the [...]

Ensuring That Your CPT Data is Correctly Reported and Interpreted

It is important to understand when interpreting CPT data the physics of how the data is produced. This will lead to a better appreciation of where CPT data should be validated with other types of tests in order to ensure that it is being correctly reported and interpreted. In CPT (Cone Penetration Testing), when the tip of the cone is being advanced, there is pressure exerted on the tip itself. This pressure is created from the resistance to downward force by whatever soil is resisting on the cone tip. However, this pressure is not simply exerted from the ground immediately in front of the tip. Rather, the cone forces the ground immediately in front of it to compress. This compression forces the ground in front of it to 'fail' that is, the soil cohesion is not sufficient to resist the tip load, and the soil compresses further down or moves out of the way down, sideways or a little bit away from the cone itself, upwards. Because of this movement and compression, the pressure exerted back on the cone tip is generated from a large area of soil below, around and a bit behind the cone tip itself. This means depending on soil stratification that the instruments in the tip sense soil resistance from around 5 or more cone diameters ahead and around the tip of the cone. Using a cone of 1.5 inches in diameter means that you are actually taking an average cone resistance measurement. This is sometimes called a 'tip influence zone'. If you are pushing through a sub-surface feature, such as a landslide slip face or a layer of softer clay that is a foot or less, it is quite possible to miss this feature entirely. In engineering speak, you might read something like 'exercise caution [...]

Cone Penetration Test (CPT) Overview 101

Are you new to the Cone Penetration Testing (CPT) business? Or maybe you're looking to convert your operation to CPT? Wherever your interest is surfacing from, we have everything you need to know about expanding into the CPT business with confidence. What do I get from a Cone Penetration Test (CPT)? In case you're new to the Cone Penetration Testing business, CPT will collect important subsurface information from standard tests and then from there determine important business factors, such as, how to design foundations for structures or the composition of subsurface soils. The difference between this type of data collection and other competitors is the benefit CPT has for businesses. CPT can provide immediate, onsite information that is quick and accurate. Above all, onsite results can improve your business productivity; ultimately leading to a more efficient business process. If you had the chance to take a look at our Solutions Brief: Enter the Cone Penetration Business with Confidence, then you may have already taken a deep dive into the advantages of collecting subsurface information with a process that is more quick and efficient than other options. Businesses are choosing to use a CPT solution for many different reasons; whether for construction or government purposes, they all benefit from the same advantage: speedy collection and interpretation of data, a safe solution for operators and the environment, and the ability to adapt to different weather and soil conditions. We understand how intimidating it can be to enter a new business; large or small. That's why we are focused on delivering educational content that addresses all of your CPT needs and concerns. From topics on 'What is a Cone Test' to 'Mud Rotary Drilling vs. CPT,' it's important to consider pros and cons and different scenarios in order to make the right choice [...]

Converting a Drilling Rig into a CPT Platform

If you're familiar with our CPT University blog then you may have had a chance to take a closer look into what CPT can do for your business. If you're yet to make the switch; it may be because you don't exactly have the means to support the transition into the CPT business. Fortunately, if you're still looking to reap the benefits of CPT rigs, the Vertek CPT Drill Rig Adapter may be the solution that you have been searching for. Read on to learn how you can start growing your drilling business. Converting a drill rig into a CPT platform using a Vertek CPT Drill Rig Adapter Businesses that transition out of SPT or Hollow Stem Auger Drilling are able to become more efficient and obtain a higher daily rate. How Does it Work? The drill rig CPT adapter kit enables drilling service providers to complete CPT testing with their existing equipment. So how does it work exactly? The simple adapter is first screwed onto the drill head. This enables the existing push and pull hydraulic system to advance and retract the CPT equipment to and from the subsurface. This is just a small snippet of what the drill rig CPT adapter kit can do, for even more on it's functionality, visit our drilling conversion page. A CPT Drilling Conversion Rig Kit Consists of: A Peizo-Cone Penetrometer A Data Acquisition System (DAS) and coaxial communication cable A Depth Marker for depth measurement A Drill Head Adapter for advancing and removal Rods or Rod Adapters Wear surface consumables and spares (tips, sleeves, pore pressure filters) Seismic shear wave equipment (optional) Converting a drilling rig can be a cost-effective entry into CPT. By following this route, you can enter the CPT business with a brand that offers exceptional domestic support and [...]

Towable CPT Trailer – Push System on Wheels!

New - Mount an S4 CPT Push System on equipment or a trailer! Customer response to our new S4 Push System has been very impressive. The most affordable and flexible 20 ton push system available has made CPT newly accessible to a variety of service providers around the world without the need for large dedicated vehicles. In keeping with our history of cone penetration innovation we'd proud to show off our latest improvement to the S4 Push System: Towability. That's right, the S4 can now be purchased attached to our custom trailer enabling it to be driven from job site to job site behind any full size pick-up truck. [/fusion_youtube]

Building a CPT Truck in Less Than 3 Minutes (Video)

This short video compresses about a month of construction time on a 20 Ton CPT Truck built by Vertek CPT at our Vermont facility during the summer of 2014. CPT Trucks are popular for those looking for maximum push force and all-in-one mobility. This truck will be delivered to the customer upon completion of the internal components. Large trucks provide greater push force and improved working environs while smaller trucks provide greater mobility in tight spaces. Contact us to see which is best for you. Our new S4 Push System also provides a path to entering the CPT market with limited investment. [/fusion_youtube]

Cone Penetration Testing Glossary of Terms

This brief glossary contains some of the most frequently used terms related to CPT/CPTU. These are presented in alphabetical order. CPT: Cone Prenetration Test or the act of Cone Penetration Testing. CPTU: Cone Penetration Test with pore water pressure measurement - a piezocone test. Cone: The part of the Cone penetrometer on which the end bearing is developed. Cone penetrometer: The assembly containing the cone, friction sleeve, any other sensors and measuring systems, as well as the connections to the push rods. Cone resistance: The total force acting on the cone, divided by the projected area of the cone. Corrected cone resistance: The cone resistance corrected for pore water pressure effects. Corrected sleeve friction: The sleeve friction corrected for pore water pressure effects on the ends of the friction sleeve. Data acquisition system: The system used to measure and record the measurements made by the cone penetrometer. Dissipation test: A test when the decay of the pore water pressure is monitored during a pause in penetration. Filter element: The porous element inserted into the cone penetrometer to allow transmission of the pore water pressure to the pore pressure sensor, while maintaining the correct profile of the cone penetrometer. Friction ratio: The ratio, expressed as a percentage, of the sleeve friction, to the cone resistance, both measured at the same depth. Friction reducer: A local enlargement on the push-rod surface, placed at a distance above the cone penetrometer, and provided to reduce the friction on the push rods. Friction sleeve: The section of the cone penetrometer upon which the sleeve friction is measured. Normalized cone resistance: The cone resistance expressed in a non dimensional form and taking account of stress changes in situ. Net cone resistance: The corrected cone resistance minus the vertical total stress. Net pore pressure: The meausured pore [...]

What is Triaxial Testing and is it the Best Method for Testing Soil?

Those familiar with soil testing probably already know that there are a number of ways to test soil. One of the most common methods is the Standard Penetration Test, which is best known for its simplicity and versatility, but is held back by its lack of accuracy compared to more advanced options. More advanced methods include, of course, Cone Penetration Testing and Mud Rotary Drilling, both of which are common. Another common method is Triaxial Testing. What is Triaxial Testing? In order to conduct Triaxial Testing, you need a Triaxial Apparatus, which is made up of a Triaxial cell, universal testing machine and pressure control panel. For testing soil and other loose granular materials like sand and gravel, the material is placed in a cylindrical latex sleeve and submerged into a bath of water, or another liquid, which puts pressure on the sides of the cylinder. A circular metal plate at the top of the cylinder, called a platen, then squeezes the material. The distance the platen travels is measured, along with the net change in volume of the material. Like Cone Penetration Testing, Triaxial Testing is used to measure the properties of soils, but can also be used on more solid materials like rock. Typically, Triaxial Testing is used to solve problems of stability by: Determining the shear strength and stiffness of soil when retaining reservoirs of water Measuring stress/strain behavior Monitoring the internal response of the particulate medium It is also used for pore water pressure measurement and determining contractive behavior, which is common in sandy soil. As such, this soil testing method is well-suited to helping engineers improve their building designs while limiting structural/build failures by imparting a proper understanding of material behavior and an assessment of the characteristics of a build site. Primary benefits of Triaxial [...]