Why Would You Need a Track CPT Rig?

Vertek CPT wants to ensure that you have the right equipment to grow your business. As you are going through the CPT rig purchase process, we’ll have extensive conversations to ensure that we are both on the same page when it comes to where you will be testing, what types of tests you can most easily sell, and which rig or rigs will help you to make the most money. Track Rig Features As you look around our site, you’ll see that some rigs are built on tracks, as opposed to truck beds with wheels. As per with construction equipment, you might expect the tracked equipment to be larger, with CPT rigs the tracked units tend to be smaller. This is because tracked rig CPT platforms are designed to not only traverse and work in difficult terrains, but also to be highly maneuverable around obstacles such as trees, rocks and gulleys. Remember, CPT testing may be specified by your customer for pre-construction activities, meaning that it takes place on a site with little preparation. Having a highly maneuverable platform with low ground pressure can make the difference between you being able to win certain jobs and not. Track rigs are usually designed in order to distribute the weight of the rig over more square inches of contact area. This helps to minimize damage to sensitive areas as well as help the rig not get stuck in less than optimum ground conditions. The overall rig footprints are designed so that the units can be effectively trucked to sites within your service area. Track rigs are designed for deep pushes in tough geologies and the Vertek CPT tracked rigs push from about 10 tons up to 25 tons. With the right combination of weight, ease of maneuverability and set-up features, a tracked [...]

Measuring the Moisture Content of Soil Using CPT

Measuring soil moisture content can be important for a variety of reasons. In placing underground electrical equipment or digging tunnels, it can be essential to know exactly what soil moisture conditions look like at specific depths. Early CPT test procedures used the standard CPT output data of cone resistance, sleeve friction and friction ratio to identify all of the parameters underground. When it comes to soils that have some moisture content or are saturated, it can be helpful to use a boring rig to obtain soil samples at depth close to the first CPT sounding. This enables you to ‘calibrate’ your rig to the site to ensure that the interpretations of the test data are accurate. Because establishing subsurface moisture content can be safety-critical in certain cases, Cone Penetration Testing methodologies have evolved to provide relative soil moisture content data. It is now possible to measure soil moisture more directly at the cone head vs. inferring what the moisture might be through interpreted sounding data. One method of measuring the presence of water is with a ‘piezocone’. This is a CPT cone that is fitted with a device that measures pore pressure. As the cone penetrates into saturated soils, hydraulic (water) pressure is exerted on the instrumented cone. By watching this pressure increase and decrease as the cone is driven deeper into the ground, it is possible to measure the presence of moisture at depth. This type of approach is better suited to soil conditions in which it is expected for the soil to be fairly wet to saturated conditions. Another method of establishing the extent of the presence of water is by using electrical sensors such as a dielectric probe, which measures soil electrical conductivity. This can be a useful practice and can be helpful in soils with less [...]

Soil Electrical Conductivity

In terms of measuring soil contamination, measuring soil electrical conductivity can provide useful information for a more complete site characterization study. Measuring sub-surface soil electrical conductivity is becoming less expensive as well as faster and easier. This form of measurement has most commonly been used for measuring physical and chemical soil properties but the ability to pinpoint contaminants is improving, particularly with software designed for the job. How to Measure Soil Conductivity Measuring soil electrical conductivity is facilitated by two different types of sensors, a contact sensor and a non-contact sensor. Contact sensors work by making contact with soil to measure electrical conductivity directly. These types of instruments are most often used along the surface of a field to characterize the soil for agricultural purposes. Non-Contact Sensors Non-contact sensors, as the name implies, function without having to touch the soil directly. This method is based on the measurement of the change in mutual impedance between a pair of coils passed through the soil. Electricity is applied through the coils, which creates a magnetic field. Much like the way an induction motor operates, this magnetic field induces an electrical current in nearby materials that are magnetic. You can assess the level of current induced by measuring the impedance in the operating coils. Passing non-contact sensors down a borehole has been used effectively to establish geophysical properties such as the presence of clay (which may have highly conductive materials distributed through it) and water table levels. In cases where an area is known to have contamination, the identification of clay layers and groundwater distribution can help to estimate where 'plumes' of contamination might be contained orspread underground. In the case of a borehole test, water samples can be gathered directly from discrete depths to confirm the presence of various types of contaminants. [...]

Attending CPT Symposium 2014 Las Vegas, Nevada

See The Vertek S4 Push System in Person! The 3rd International Symposium on Cone Penetration Testing will be held at the Mandarin Oriental hotel in Las Vegas, Nevada, May 12-14, 2014. The theme of the Symposium is the solution of geotechnical and geo-environmental problems using the Cone Penetration Test (CPT). We'll be at booth #1 and also setup outside with our new S4 Push System which is designed to be attached to a wide variety of equipment. Learn more about our entire line of products and data acquisition systems.

CPT Case Study: GEI Consultants

30 years of Cone Penetration Testing with GEI We're proud of the relationship we have with our long time customers. We succeed together. One of these groups is GEI Consultants, which has been delivering engineering services around the globe since 1970. Sean Brady, Senior Instrumentation Specialist with GEI, provided CPT University with background on their operation as it pertains to their CPT efforts. Briefly describe GEI’s engineering focus. What do you do for whom? GEI is a medium size engineering firm with around 700 employees in the United States. Our business line within GEI is Geo-technical, non-destructive testing, and geophysics. Our engineering’s have designed over 75% of downtown Chicago’s foundations and most of the tallest buildings in the world. We often are part of the design team when difficult and challenging soils are encountered. We perform CPT’s on earthen dams/embankments, river sediment depths, USCOE projects from Ft. Peck Montana to New York, RR alignments, bridge embankments, and Power plants. A little of everything you can imagine from Water, RR bridges, Landfills, stability of tail basins for the mines. We also oversee other companies performing CPT. We just worked in Asantana, Kazahkstan overseeing a new energy exposition 2016 project for both SPT’s and CPT. Also have overseen CPT testing in Doha, Qatar. When did CPT first become of interest and why? We have over 30 years of CPT testing experience. In the late 80’s we purchased a 30T CPT truck and traveled around the US performing CPT on challenging geo-technical projects. In the mid-90’s we sold our truck and started to perform CPT testing behind drill rigs. At the time we had a fleet of 18 drill rigs from track mounted, ATV, truck mounted, Barge mounted, etc. We get involved with delicate soils all the time. In some cases even when [...]

Cone Penetrometer Testing via Speed Lock Rods

The strongest direct push rods in cone penetration testing. Unsurpassed Joint Strength Vertek manufactures a full line of CPT push rods with our proprietary Speed Lock dual-lead thread design. Speed Lock Rods provide unsurpassed joint strength, up to 50% stronger than industry standard V-threads. Our unique rope thread design uses less of the available wall thickness and balances the strength between the male and female thread ends. Speed Lock coupled joint achieves nearly 90% of the strength of the heat treated rod stock. Increase Speed, Reduce Operator Fatigue Our dual-lead thread provides fast coupling; 2.5 turns to couple or uncouple compared with 5-7 turns for competitor’s rods improving worksite productivity. Flexibility and Adaptability to Variety of Cones Speed Lock Rods are available in standard 1.44” and 1.75” diameters. Custom sizes include 2”, 2.25” and 2.5”. Vertek also manufactures custom adapters to permit use of our advanced thread design with your current inventory of CPT equipment. Make the most of your CPT rig and cone penetrometer testing equipment with Vertek Speed Lock Rods!

The Advantages and Disadvantages of Geotechnical Boring; Why CPT May be Your Better Option

As we noted in a previous post about Soil Quality, there are a wide range of reasons that soil needs to be tested. For some applications, it is important to get data about soil that is sub-surface, and in many cases getting data from deep under a site can be useful or essential. When most people imagine how you would gather data from soil that is deep underground, they imagine using a drilling rig of some kind. Sure enough, there are special kinds of boring tools that will let you drill deep into the ground and extract a sample of the soil at depth for analysis. Advantages & Disadvantages of Geotechnical Boring Using Geotechnical Boring, whether it be small-diameter or large-diameter equipment allows users to see the solid that is extracted. This can be useful for gaining an understanding of the sub-surface topology if a goal is to create a multi-dimensional map of the subsurface Geological conditions. There are significant disadvantages however to using Geotechnical Boring to obtain soil samples for testing. One disadvantage is that the operation of boring is for obtaining samples only, you can't gather data from the boring activity itself and therefore all of this investment in equipment, labor and time provides value only in that it presents a sample for testing. Another disadvantage is that the soil being sampled then needs to be tested using some type of laboratory equipment. This often means removing a large number of samples from the site, getting them safely in an organized way to a lab facility somewhere, hopefully nearby, and waiting for the lab results to come back. If there are apparent conflicts in data, or a particular part of the site needs more evaluation, the entire process needs to be started up from scratch again. Perhaps the [...]

CPT Testing, Part 1: Introduction to the Basic Concepts

If you have ever been curious about the Cone Penetration Testing (CPT) business, you have come to the right place. In today's post we are going to take a dive into the basic concepts and what expanding into CPT can do for your engineering business. Geotechnical Engineers and CPT Testing Geotechnical engineering is a branch of civil engineering that focuses on the engineering behavior of earth materials. Geotechnical engineers have been using Cone Penetration Testing (CPT) for over 40 years to assist in the design and construction of foundations, embankments and other structures. The standardized CPT works by pushing a 55-60 degree cone into the ground at a rate of 1-2 cm per second and is used to identify the conditions in the upper 100 feet of the subsurface. The data compiled from this testing is valuable for assessing the subsurface stratigraphy associated with soft materials, discontinuous lenses, organic materials, potentially liquified materials (such as sand, silt and granule gravel), and predicting landslides or ground settling. The cone resistance in conjunction with the friction ratio can also be used to determine soil types. While these results are often more accurate when referring to textbook soils, there are some major benefits to utilizing CPT techniques as opposed to drilling. In fact, there are a number of different advantages of CPT, including: economically friendly testing, as well as its ability to perform at a fast rate and effective in characterizing large volumes of soil without having to do a large number of laboratory testing. CPT is also accurate, eliminating the possibility of disturbances to soil samples and sample storage. By leveraging CPT results, engineers can determine the best methods for several aspects of design and construction projects. Detect lenses, thin layers and sand stringers. Evaluate the thickness and extent of compressible soil [...]

What to Consider Before Buying a Used CPT Rig

When faced with the prospect of a major purchase, it’s common to look into the possibility of buying used. In most circumstances, this is a perfectly valid option with a number of upsides, the most obvious of which being a lower upfront investment. However, when it comes to buying a used CPT Rig, you might be better off buying a new rig from a trusted vendor. Here’s why. Used Means Used First and foremost, Cone Penetration Testing is too important to leave up to chance. Sure, your used CPT Rig may appear in fine working order and you may have acquired it from a reputable seller, but there’s no getting around the simple fact that a used rig has a higher chance of failing than a brand new one. This point is further compounded when you consider the fact that even the best used CPT Rig dealer can’t match the expertise of a CPT Rig manufacturer. Expertise Straight from the Source When you buy a CPT Rig from Vertek CPT, you’re also getting access to our knowledgeable technical sales staff; something used CPT Rig sellers can’t offer. Additionally, in some instances, Vertek CPT will provide comprehensive training and will even accompany you to your first job site to maximize your chances of success. You can’t get that kind of service or expertise from a used CPT Rig dealer. Even if you think you have enough experience with CPT Rigs to ensure success with a used rig, though, it’s also worth noting that not every CPT Rig is right for every task. A Wide Variety of CPT Rigs If you have a broad enough knowledge base to feel comfortable buying and setting up a used CPT Rig, then you probably also know that there are many kinds of CPT Rigs. Cone [...]

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 [...]