Geotechnical evaluation, quality control, and other services are provided by Geotill in Lexington, Kentucky in addition to Geotechnical Engineers in Louisville

California Issues Maps of Earthquake Faults to Avoid ‘Potentially Devastating’ Damage to New Buildings

Source: State Issues Maps of Earthquake Faults to Avoid 'Potentially Devastating' Damage to New Buildings - Times of San Diego The Rose Canyon Fault system. Courtesy County News Center Maps released Thursday of earthquake-prone areas are intended to ensure new construction in San Diego does not take place atop dangerous quake faults. Developed by the California Geological Survey, the regulatory Alquist-Priolo Earthquake Fault Zone maps detail where local governments must require site-specific geologic and engineering studies for proposed developments to ensure this hazard is identified and avoided. Generally, new construction for human occupancy must be set back 50 feet from the active surface trace to avoid faults that may break the surface. “Surface fault rupture is the easiest earthquake-related hazard to avoid because you can see the evidence of where it has occurred,” said Steve Bohlen, acting state geologist and head of CGS. “Surface fault rupture means that one side of a fault is moving either vertically or horizontally in relation to the other side. The deformation that movement causes is potentially devastating to buildings and infrastructure.” Two maps of revised Earthquake Fault Zones have been prepared for the Rose Canyon Fault where it comes onshore in Coronado, traversing the San Diego area to the northwest and going back offshore near La Jolla. Each of the maps covers a roughly 60-square-mile quadrangle of territory. The Alquist-Priolo Act was passed into law following the 1971 magnitude 6.6 San Fernando earthquake, which caused extensive surface ruptures that damaged buildings. Not every large earthquake, though, causes surface fault rupture. For example: the Loma Prieta Earthquake of 1989 devastated the Bay Area without breaking the surface. However, the 1992 Landers Earthquake in San Bernardino County caused surface ruptures along 50 miles, with displacements ranging from one inch to 20 feet. “Since the [...]

Dynamic behaviors of wind turbines under wind and earthquake excitations

Source: Dynamic behaviors of wind turbines under wind and earthquake excitations: Journal of Renewable and Sustainable Energy: Vol 13, No 4 Source: How Do Wind Turbines Respond to Winds, Ground Motion During Earthquakes? - AIP Publishing LLC A new study investigates the combined effect of wind and earthquake forces to assess the dynamic behavior of wind turbines. The demand for renewable energy is nowadays at its peak. Wind power is a great source of clean energy and is harvested via wind farms placed in numerous regions across the world. This has led to some winds farms being established in earthquake-prone regions making it important to assess the combined excitation under wind and earthquake forces. In the US, these wind farms are most commonly seen in Alaska, Arkansas, California, Idaho, Illinois, Kentucky, Missouri, Montana, Nevada, Oregon, South Carolina, Tennessee, Utah, Washington, and Wyoming. The study, recently published in the Journal of Renewable and Sustainable Energy, aims at establishing a numerical model that will integrates both seismic, wind, and operation forces of wind turbines to evaluate the performance of the wind turbines. This is referred to as the "fully coupled model". Such models have been tested before but the research team emphasizes that a solid interpretation of the results is still missing. The authors studied a 5MW wind turbine subjected to a combination of wind load and input ground motion with the latter being retrieved from a list of earthquake records. The study provides some interesting findings. The results from the sophisticated numerical models suggest that the wind that acts as a dynamic load for the wind turbine also exerts a damping effect on the response of the structure. In particular, when shaking is strong, the energy absorbed due to the aerodynamic damping is higher than the actual wind loading generates hence, the [...]

Reusable Ionic Liquid from Coal Fly Ash Enables Extraction of Rare Elements

Source: Reusable Ionic Liquid Enables Extraction of Precious Rare-earth Elements from Coal Fly Ash | School of Civil and Environmental Engineering Turnipseed Family Chair and Professor Ching-Hua Huang, left, and Ph.D. candidate Laura Stoy, right, published research outlining a new method for extracting rare-earth elements from coal fly ash.  By Melissa Fralick  Researchers from Georgia Tech’s School of Civil and Environmental Engineering have discovered a way to extract rare-earth elements—essential ingredients for nearly all modern electronics—from the ash left behind at coal-burning power plants using a non-toxic ionic liquid. In a paper published in ACS’s Environmental Science and Technology on June 23, the Georgia Tech researchers showed that by applying an ionic liquid directly to solid coal fly ash, rare-earth elements can be successfully removed in a safe process that creates little waste. The study is co-led by Ching-Hua Huang, a professor of environmental engineering and Ph.D. candidate Laura Stoy. A third co-author, Victoria Diaz, is an undergraduate student who joined the lab as part of Georgia Tech’s Summer Undergraduate Research in Engineering/Sciences (S.U.R.E.) program. Rare-earth elements (REEs) are a set of 17 elements that are utilized to make everything from permanent magnets in windmills to LED screens for computers and smart phones. While rare-earth elements aren’t as scarce as their name implies, only a few locations around the globe have deposits large enough to mine directly. Many of these reserves are in politically sensitive locations, resulting in global supply chain tensions. “Right now, China produces over 80 percent of the world’s supply of rare-earth elements, meaning that if something were to happen to disrupt the global supply chain— like a ship getting stuck in the Suez Canal, or a pandemic, or a trade war with China—United States manufacturing might be cut off,” Stoy said. “Our work is one of many efforts to secure a [...]

UD researchers study climate change impacts on soils at military installations

Source: The Ground Underfoot - Civil and Environmental Engineering UD researchers study climate change impacts on soils at military installations We walk over it, drive over it and build on it. Yet, it is probably safe to say, most of us rarely think about the ground beneath our feet. Underneath the grass, concrete, asphalt and other materials in our built environment, however, soil provides structure and stability for what lies above. The United States military wants to understand the role that climate impacts, such as flooding, storm surge or sea level rise, will have on soils at its coastal military bases and facilities, which are critical to national security. Soil conditions can affect the integrity of the ground underpinning buildings, roads, bridges and more. For example, if a soil’s pH were to rise significantly, due to increased salt content-containing ions such as sodium from storm surge, it could create saline conditions that could hamper the ground’s ability to support this necessary infrastructure. Understanding these threats will enable faster and more accurate routing and maneuverability for U.S. forces. The Delaware Environmental Institute (DENIN) is collaborating with the Engineer Research and Development Center (ERDC) of the U.S. Army Corps of Engineers and Louisiana State University to understand how vulnerable military installations along coasts may be affected by soil changes due to sea level rise and coastal flooding. DENIN has received $3.79 million in first- and second-year funding from the U.S. Department of Defense to start this work, and is eligible for an additional $3.82 million in continued funding over the following two years. Led by DENIN Director Don Sparks, Unidel S. Hallock du Pont Chair of Soil and Environmental Chemistry in UD’s Department of Plant and Soil Sciences, the UD effort includes interdisciplinary collaboration with Yan Jin, Edward F. and Elizabeth Goodman Rosenberg Professor [...]

Parameters Variation Model Customization and Sensitivity Analyses

Source: Parameters Variation: Model Customization and Sensitivity Analyses Parameters Variation Model Customization and Sensitivity Analyses A well-known engineering challenge in the framework of finite element (FE) analysis-based design is the large number of input factors involved in geotechnical computational models. There is always a significant amount of uncertainties associated with the properties of geomaterials, being naturally highly heterogeneous materials. In the context of model calibration and validation, conducting a sensitivity analysis is very important. This can determine the key factors which govern the system and efficiently characterize the geotechnical variability for any considered design problem.   Powerful mechanisms for the consideration of parameter variation are also very interesting for speeding up FE model creation and automating results in post-processing. These are also quite useful in reducing model definition for specific types of engineering problems (excavation wall of a specific type under simple ground conditions, simple tunnel shape in uniform rock mass, etc.) to a limited number of parameters that can be inputted in a text file or Microsoft Excel spreadsheet without expert knowledge of the PLAXIS user interface and different modeling techniques and FE know-how. The sensitivity analysis and parameter variation tool in PLAXIS A sensitivity analysis determines how different values of an independent variable affect a particular dependent variable under a given set of assumptions. In other words, sensitivity analyses study how various sources of uncertainty in a mathematical model contribute to the model's overall uncertainty. The Sensitivity Analysis and Parameter Variation tool (see Figure 1) can be used to evaluate the influence of model parameters on calculation results for any particular PLAXIS FE model: The Select Parameters tab sheet will first provide information about all the parameters that can be changed to perform the sensitivity analysis. Available parameters include most model parameters of the data sets for soil and [...]

A Climate Change-Induced Disaster in Denali National Park

Source: A Climate Change-Induced Disaster in Denali National Park | Time The Times has recently showcased an article on the current rockslide situation in Denali National Park. The effects of climate change have been dramatic with the current melting of the permafrost. The National Parks Service has recently upped through gravel removal of the Pretty Rocks Landslide in an effort to keep up as the rapidly thawing permafrost picks up pace. Alaska is right now recognized as the country’s fastest-warming state. The landslide hit unprecedented speed 4 weeks ago causing the team to close the back half of the park weeks earlier than anticipated. This only signals bad news as reservations are canceled in the short term and the long term implications are yet unknown. “This is the canary in the coal mine for infrastructure disruption in Alaska,” says the Camp Denali lodge owner Simon Hamm. “If things continue on the path they’re on, it’s not going to just be Pretty Rock—it’s going to be half of the Alaskan highway system.” Rapid deterioration Denali National Park is one of the U.S.’s largest national parks at 6 million acres, and sits about four hours north of Anchorage. While the entrance to the park is certainly beautiful, many people prefer to hop on buses to access the park’s marquee attractions deep down its single 92-mile road: views of Mt. Denali (formerly Mt. McKinley), the highest peak in North America at 20,000 feet; the gleaming Wonder Lake; rolling mountainsides that contain an abundance of wildlife, including grizzly bears, moose, caribou and bighorn sheep. About halfway along the road lies the Pretty Rocks Landslide, a slowly sliding section of earth that acts more like a glacier than a rockfall. Since the 1960s, permafrost deep below the earth’s surface has thawed, causing the soil and [...]

Geotechnical Instrumentation and Monitoring Consumption Market Size to Witness Huge Growth by 2027 | By Top Leading Vendors – Keller, Fugro, Nova Metrix, Geokon, Geocomp, Sisgeo, Cowi – The Daily Chronicle

Source: Geotechnical Instrumentation and Monitoring Consumption Market Size to Witness Huge Growth by 2027 | By Top Leading Vendors – Keller, Fugro, Nova Metrix, Geokon, Geocomp, Sisgeo, Cowi – The Daily Chronicle

Screening for Soil Contamination Levels with CPT

Expanding from geotechnical Cone Penetration Test (CPT) into other services is a great way to grow your business. Evaluating subsurface soil contamination provides many business opportunities and a way to differentiate yourself from other CPT service providers – allowing you to protect your business, while expanding into new regions and adding clients. In many instances, the existence of environmental contaminations in an area is known, but the question that needs to be answered is, “where is it”? In other posts, we explain how CPT works, and how it can be used to characterize the strata underground hundreds of feet deep, depending upon the actual subsurface conditions, the equipment being used etc., In addition to identifying soil types by layer and depth, geo-technical CPT testing also helps to establish groundwater levels and potential migration pathways. This makes it useful for identifying where contamination may migrate or be confined. Establishing a depth profile of the contamination underground and how the ‘plume’ is located and migrated, or where it is likely to expand in the future is vital to establishing a cleanup or remediation plan. Once contamination has been shown to be likely, our discrete soil and ground water sampling equipment delivers physical samples for confirmation. Once CPT became well-established and proven as a geo-technical evaluation tool, it was natural to try and see what other types of testing could be accomplished using the same tools. In addition to mapping groundwater conditions with in-situ pore pressure transducers, CPT tools that sense the direct presence of various types of hydrocarbons and other volatile organic compounds at depth are now available. A variety of cone sensors can be used to test for specific types of contamination. Multiple CPT equipment modules can be configured with multiple sensors, including soil moisture resistivity, video, radiation and sensing for [...]

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

Geo-technical Boring is less accurate, less efficient and more expensive than Cone Penetration Testing (CPT), here's why. When it comes to selecting a method for subsurface investigation and testing you are presented with different options. From the Standard Penetration Test (SPT), which is a type of Geo-technical Soil Boring to Cone Penetration Testing (CPT) there are many options to consider, and each provides certain advantages over the other. Today we’re going to compare Geo-technical Boring to CPT. Geo-technical boring is a method of drilling which is performed for site investigation. This drilling technique is most commonly used to obtain information on the physical properties of soil and rock under a foundation. This information helps to determine the depth of the foundation, 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 geo-technical boring using a hollow stem auger is the Standard Penetration Test. Like it's name suggests, a hollow stem auger is a drilling tool that enables you to capture soil samples in the hollow portion of the drill for retrieving to the surface. One advantage of this approach is that you have actual soil samples you are working with. In the case of identifying the presence, location and depth of specific types of contaminants, this can be useful. Cone Penetration Testing Though geo-technical boring seems like a sufficient option for site subsurface investigation, geo-technical boring doesn’t provide the accuracy and efficiency that Cone Penetration Testing (CPT) can offer. Geo-technical 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, Geo-technical Boring can require less skilled operators [...]

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 [...]

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