Vertek CPT

Division of ARA

Archives for February 2014

Why Are There So Many Kinds of CPT Rigs?

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introductory

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 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 makeup of the soil. [Read more…]

Filed Under: CPT

Measuring the Moisture Content of Soil Using CPT

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experienced

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 a 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 moist conditions. One factor to remember is that since the salinity of the water can affect conductivity, that the test again should be calibrated to ensure that the data being interpreted is relevant to the actual site conditions.

It has been found that generally, the salinity is consistent within a site, so one calibration boring should be sufficient to ensure accuracy.

 

 

Filed Under: CPT

Join us at Geo-Congress 2014 – Booth #105

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Geo-Congress 2014, Atlanta, Booth 105

Join us at Geo-Congress 2014 in Atlanta starting Sunday, February 23rd  and running through Tuesday, February 25th, 2014. We’re excited to be a part of this historic gathering, the first Geo-Institute conference focused on sustainability.

CPT is an important part of structural design, including sustainably focused projects. It is also a vital technology for groundwater monitoring, protection, and soil remediation which are essential to sustainable development.

Vertek CPT is excited to be sharing the latest breakthrough CPT tools including the new S4 quick attach CPT system!

We’ll be planning our spring product demo schedule that is kicking off in May. So stop by booth #105 to arrange a time and place to experience these products first hand and see how Vertek CPT can help you to be successful in the CPT business.

Hope to see you there!

[Read more…]

Filed Under: CPT

Hollow Stem Augers Don’t Provide the Accuracy that CPT has to Offer

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Geotechnical boring with hollow steam augers is less accurate, less efficient, and more expensive than Cone Penetration Testing (CPT)

If you want a dependable way for site testing that reduces your risk and makes your projects successful, you need to look at cone penetration testing equipment rather than a hollow stem auger.

When selecting a method for subsurface investigation and testing, you are presented with different options.

There are many options to consider, from the Standard Penetration Test (SPT), a Geotechnical Soil Boring to Cone Penetration Testing (CPT). Each provides certain advantages over the other. Today we’re going to compare Geotechnical boring to CPT.

Geotechnical boring is a method of drilling which is performed for site investigation. Geotechnical boring drilling technique is most commonly used to obtain information on soil and rock’s physical properties under a foundation. 

Geotechnical boring information helps determine the foundation’s depth, ensure the site is safe, and determines if structural compensations will be needed. 

This also ensures that the foundation, caissons, and various supports are built in the right place.

Hollow Stem Augers

One type of geotechnical boring using a hollow stem auger is the Standard Penetration Test. 

As its name suggests, a hollow stem auger is a drilling tool that enables you to capture soil samples in the drill’s hollow portion to retrieve the surface. 

One advantage of this approach is that you have actual soil samples you are working with. Identifying the presence, location, and depth of specific types of contaminants can be useful.

Cone Penetration Testing

Though geotechnical boring seems like a reliable option for site subsurface investigation, geotechnical boring doesn’t provide the accuracy and efficiency that Cone Penetration Testing (CPT) can offer. 

Geotechnical Boring has the advantage that it uses many of the skills of conventional well drilling. Because the Boring operations and technical analysis, such as laboratory tests, are separate, Geotechnical boring can require less skilled operators on-site than CPT. 

However, a price is paid in efficiency as often the site samples are sent to a separate lab for testing. This costs additional time and money while increasing earthen waste.

Though both Geotechnical Boring and CPT provide suitable options for obtaining useful information, there are many more benefits to using CPT over geotechnical drilling. 

CPT is not only a cost-effective option, but it also provides immediate electronic data for review. 

You’ll find that as you embark on CPT, that your customers value the immediacy of the results, you can provide them, as well as your ability to sample more locations more quickly than Geotechnical boring rigs can, often at an increase of 3 : 1. 

Not only is CPT a better option for proficiency, but it’s usually a lower-cost solution while delivering more data.

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General FAQs

What is geotechnical boring?

Geotechnical investigations are performed to learn about the physical properties of the rocks and soil near locations considered for construction in various situations.

What are boring geotechnical rigs?

Vertek’s S4 Push rig helps you extracting underground data to determine soil parameters to provide foundation requirements efficiently.

Who sells cone penetration testing rigs?

For more than 40 years, Vertek has provided world-class Cone Penetration Testing tools for geotechnical and environmental industries. 

What is geotechnical testing?

Geotechnical testing is performed by geotechnical engineers, geotechnical technicians, or engineering geologists to understand the characteristics, such as the physical properties that exist underneath a work site.



CPT platforms designed for Cone Penetration Testing.

Vertek CPT has one goal. To make your business a success.

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Filed Under: CPT

Presenting CPT Data to Owners & Engineers: an Important Role of CPT

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introductory

If you are considering entering the CPT business from, let’s say, operating a well-drilling business, you’ll want to prepare yourself for a few adjustments. Depending upon the type of business you are used to running or being a part of, you’ll find that the customer interactions may be different. CPT testing is all about gathering data from field tests and quickly turning that into useful information for the site owner, an engineer, construction company, government agency etc.

This blog is an introduction to the basics of CPT reporting. We’ll start with what we’re trying to measure, then we’ll discuss how a CPT system, and in particular the probe, gathers specific types of useful data. Then we’ll, look at some ways that this data is interpreted to make useful information for your customer to make decisions. In real life, you’ll want to use a software application that quickly and efficiently does this interpretation for you. However, Vertek CPT believes in training it’s customer partners from the ground up (so to speak) so that you are comfortable and confident in every conversation you’ll have. [Read more…]

Filed Under: Uncategorized

Integrated Products Division of ARA

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Phone: 802.728.4588
Fax: 802.728.9871
Email: sales@vertekcpt.com

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