Mud Rotary Drilling and Cone Penetration Testing (CPT) both provide reliable options for gaining subsurface information. In fact, the two are even compatible – many organizations that order drilling services, such as mud rotary drilling are also using CPT for their operations. Mud Rotary Drilling Mud rotary drilling is a versatile and dependable method for geological drilling operations. It is most commonly used to create a hole that will then be used for water well, seismic testing and commercial drilling operations. The mud rotary drilling functions with a drill-bit that is attached to a drill-rod that rotates into a borehole. This is done while pumping a drill mud that contains bentonite or polymer slurry into the borehole. Once this operation is complete, the drilling mud will circulate into a mud pit where the remaining residue in the borehole caused by drilling will then come out and be reused. This process is done without any effort from the drilling operators, and speeds up the drilling by removing any potential obstacles. Cone Penetration Testing (CPT) Cone Penetration Testing (CPT) is the use of a hardened cone shape that is pushed into the ground to substantial depths. The cone is pushed using steel rods that are able to be connected to each other as the depth increases. A dominant hydraulic ram is used to produce a considerable amount of downward force to facilitate the cone to penetrate soft soils, sand and clay. Though both provide suitable options for obtaining subsurface information, there are many benefits to using CPT over drilling. First off, CPT is a faster, less expensive option that also provides immediate results on site. CPT can also point to where rotary mud drilling will be required which is typically because of subsurface conditions or where more sampling should be done. CPT [...]
Geo-technical tests are performed by geo-technical engineers, geo-technical technicians or engineering geologists to understand the characteristics such as the physical properties that exist underneath a work site. Geo-technical testing will include a walk around of the surface conditions as well as one or more of a variety of tests. Tests generally fall into 4 categories, test pits, trenching, boring and in-situ testing. Test Pits Test pits are much like you would expect, a pit is dug either manually or with an excavator in order to reveal the sub-surface conditions to the depth desired. Trenching Trenching is similar to Test pits except that in this case, the pit is elongated over some distance in order to establish how the sub-surface conditions change over various parts of the work site. A range of soil samplers can be used to extract test samples including shovels, hand-driven augers, split-spoon samplers, modified California samplers and Shelby tube samplers. Boring Borings, usually small-diameter borings, provide the opportunity to physically remove soil or rock samples for testing. Borings provide the advantage of letting you ‘see’ the actual materials, but for certain types of soils, the very act of boring can disturb the soil conditions and the samples extracted may not represent what the conditions will actually be for building and supporting structures since it is unscientific and void of actionable data. Generally, soil samples from the above tests are taken to a lab where they are evaluated. In-Situ Testing In-situ (in the situation, or at site) testing methods include penetration tests such as Standard Penetration Tests (SPT), which penetrate via drilling, and various Cone Penetration Tests, which penetrate via direct push . These tests measure the physical properties of the subsurface soil directly, without removal. This provides the advantages of generating a more accurate reflection of conditions [...]
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 [...]
Soil quality typically refers to three characteristics of a soil; the chemical, physical and biological properties. When used as an agricultural term, soil quality is often a measure of the soils ability to produce crops over the long term. However, because the chemical and physical properties of soils are of interest to engineers as well, soil quality is often a term used to describe soil properties of interest to designers, engineers and constructors. The soil quality parameters of most interest are the chemical properties and physical properties. We have featured a closer look into some of the other chemical properties of soils in previous posts, including the ability of soils to conduct electricity, and what this can tell us about types of soil contaminants that might be present. Here, we’re going to delve more deeply into physical soil quality, and one property of certain soils that can be fascinating, but also tragically dangerous. That property is the propensity of certain soil types, under certain conditions to exhibit liquefaction. Liquefaction and Soil Quality Liquefaction, as the name implies, is the term used to describe soil that behaves like a liquid. As you can see from the image above, this can lead to catastrophic outcomes. If the people constructing this building had a better understanding of the impact of soil quality on the stability of the structure, they might have had the opportunity to mitigate the potential damage. So clearly, the susceptibility of a soil to liquefaction is an important indicator of the soil's quality. But what is soil liquefaction? Well, as we noted above, liquefaction is when soil acts like a liquid, but how can this happen? Soil liquefaction most often occurs in loose, sandy soil types where the soil itself is mostly, or completely saturated with water. When this type [...]
Japanese CPT Services Built by Vertek Land Concierge Inc.’s subsurface technology manager Hideyuki Sato and colleague Yoshihiro Imai visited Vertek CPT's manufacturing facility for a demonstration of our S4 Cone Penetrometer Test (CPT) push system and Data Acquisition Systems (DAS). Land Concierge Inc. has been a customer of Vertek since 2009 and is our sales agent in Japan. Contact Mr. Sato with your Japanese soil testing equipment needs and questions. Vertek personnel demonstrated the versatility of the S4 and provided an interactive tour of our CPT fabrication facilities. Mr. Sato indicated that requests for CPT testing in Japan has increased since 2011 and many of his customers that are interested in incorporating Verteks’ S4 and CPT equipment into their business. Land Concierge's clients focus on: Contaminted sites Site characterization Bio-remediation Geothechnical in-situ testing Soil and groundwater sampling If your organization would like to send a representative to our Vermont facility to learn more about the CPT business and technologies, contact us today.
In-situ soil testing is essential for gaining soil property information, measuring groundwater pressure, gathering moisture content data and other important data points, all in which can be safety-critical in a number of different instances. In today's post we are going to take a deep dive into a few different types of soil tests that can be performed in-situ. In-situ soil testing can be accomplished in a variety of different ways. Every soil test has its own place and benefit; however, the most accurate and thorough in-situ soil testing for determining a wide variety of technical attributes is Cone Penetration Testing (CPT). Just like everything else, determining what is best for your business is more efficient and effective once you have determined the pros and cons for every possible solution; in this case a testing solution. Options for In-Situ Soil Testing Procedures Here is a closer look at a few different options for performing an in-situ soil test: Standard Penetration Testing (SPT): This option is dynamic, low in cost and has been widely recognized as a simplified solution that provides useful information. While it's reasonably consistent with it's results in fine-grained sands it's not as consistent with coarse sands or clays; which can be difficult for gathering accurate data and analysis of soil conditions. For even more on Standard Penetration Testing, visit one of our previous posts that takes a closer look at SPT for your business. Dynamic Cone Penetrometer (DCP): A DCP manually lifts it's weight and drops into a cone that will then penetrate into the ground. It will record the number of mm per hit as well as gather an estimate of different soil properties, however it doesn't have as many capabilities as the CPT, and can only estimate certain properties. Cone Penetration Testing (CPT): This option collects [...]
Agronomists, Civil Engineers, Geological Engineers and more will often talk about 'Soil Quality'. As a result, there can be varying definitions of what 'quality' soil means. That means that there are a wide variety of tests to determine 'Soil Quality'. What Does Soil Quality Mean for You? For the Agronomist, Soil Quality refers to the capacity of soil to provide a kind of function related to growing capacity. This will take into account the soils ability to support life as in its chemical properties (does it have enough nitrogen etc.), it's biological properties (does it have the right bio-system to support the production of certain types of crops), will it retain the right amounts of water, is it's grain size suitable for tilling etc. There are many tests that will help one to evaluate the agricultural viability of soils. For the Civil and Geological Engineer some of these tests might be valuable. For instance, in making recommendations in how to reclaim a 'brown field' (a site that was formerly industrial that is now being re-developed for other purposes) it can be useful to identify the level of ability of an area to support specific types of grasses. When performing earthworks, it is not uncommon to use plantings such as trees as part of the anchor system to help to hold berms and such in place. Knowing Soil Quality in this respect can help to support a good decision with respect to the structural support that a living ecosystem can bring. Generally though, Engineering types are after more specific physical properties in order to 'do the math' on how an engineered system will interact with the soil conditions that are present. This enables engineers to either recommend changing the systems in place (such as by excavating large quantities of soil out, [...]
Vertek S4 Push System In Action Extracting underground data to determine soil parameters in order to efficiently provide foundation requirements Vertek customer Michael Cox has launched PalmettoINSITU, LLC, a geotechnical exploration firm specializing in extracting and presenting more exact data from coastal, southeastern, and southwestern soils prior to development and construction projects. Geotechnical engineers will contract with PalmettoINSITU to extract underground data to determine soil parameters in order to efficiently provide foundation requirements for: Bridges, multi-story buildings, private residences, nuclear power plants, wind turbines, cellular communication towers, municipal water tanks, water treatment facilities, sinkholes, profiling top-of-rock, directional boring, and many other critical applications prior to development and construction. About Michael Cox: Michael Cox spent 13 years with S&ME, a global Top-100 engineering firm before launching PalmettoINSITU in June of 2014. Michael Cox graduated from Florida Institute of Technology with an MS in Information Technology and a BS in Computer Information Systems. Cox also earned an AS in Civil Engineering Technology, including AutoCAD and Surveying certificates from Trident Technical College in Charleston. Michael Cox is known as the "Indiana Jones" of capturing soil data in the geotechnical engineering space, due to his reputation and innovation for getting in and out of some of the most challenging site locations. Before beautiful residences, commercial buildings, or major facilities are built, their raw land is typically rough, wooded, wet, or otherwise a challenge to physically enter in order to begin testing the soil. Vertek's S4 Push System offers maximum flexibility to access these site locations due to application on a variety of equipment. Michael Cox earned over a decade of geotechnical experience working on the following projects: Norfolk Naval Shipyard (Virginia), Andrews Air Force Base (Maryland), The Boeing Facility (South Carolina), The Bellefonte Nuclear Station (Alabama), Robinson Nuclear Power Plant (South Carolina), The Google [...]
A Cone Penetration Test is used to collect key subsurface information from soil by pushing a hardened cone shape per ASTM International standards, deep into the ground with the help of steel rods, a hydraulic ram and, in most cases, a very heavy truck. CPT is typically used to determine the composition, distribution and strength of soil, sediment and other geological subsurface features like clay, sand, bedrock and even contaminants. The information gathered by Cone Penetration Testing can be used to inform important business decisions, like how to design the foundations of a structure. This helps prevent any future issues that could arise from building a structure blind. Of course, CPT testing isn’t the only method of soil investigation, but it is among the most commonly used and accepted, and for good reason. For starters, CPT testing offers quick collection and interpretation of field data; in fact, it is up to three times faster than traditional methods. In addition, CPT testing eliminates drill cuttings, while also being economical, environmentally friendly, safe and adaptive to various weather and soil conditions. In other words, CPT is the clear, superior choice for soil testing in the majority of situations. Best of all, thanks to developments like Vertek’s S4 Push System, it’s possible to perform CPT testing with nothing more than the CPT System and a commercial skidsteer. For a closer look at how CPT stacks up against competing methods of soil investigation, check out our ‘Mud Rotary Drilling vs. CPT’ post. If you're still curious about what expanding into the CPT business can do you your business, subscribe to our blog, or take a closer look at the video below! [/fusion_youtube]
When you think of Cone Penetration Testing (CPT) you may tend to focus on the soil being tested, which makes sense since soil testing and analysis is largely what CPT is all about. But let’s not forget another equally important aspect of soil testing: moisture. While measuring soil moisture levels isn't necessarily important in every investigation, it is often valuable information to have for your data set. When designing underground electrical equipment or digging tunnels, for example, knowing soil moisture conditions at certain depths is crucial. Measuring Moisture with a ‘Piezocone’ Measuring the moisture content of soil is a crucial aspect of CPT that is performed by a type of cone known as a ‘Piezocone.’ The Piezocone is a core component of many CPT systems; in fact, it’s actually a type of CPT cone. Able to measure the presence of groundwater, the Piezocone is fitted with a device that measures in-situ pore pressure. As such, when the cone penetrates into soils, water pressure is exerted on and measured by the Piezocone. Pore pressure data is recorded automatically during the testing process. As with any standard Cone Penetration Test, the Piezocone also measures pore pressure tip resistance, sleeve friction to provide a picture of the soil behavior being tested. Due to its relatively specialized nature, the Piezocone is typically used when soil conditions are expected to be fairly wet. The Piezocone is a standard configuration of most CPT cones while adding the ability to measure a greater breadth of information. If you found today's post interesting, subscribe to our blog for even more on the CPT business!