Studying the ground under your feet: Interview with Taylor Hall about rock and soil stability

Source: Studying the ground under your feet: Science Moab speaks with Taylor Hall about rock and soil stability | Get Out & Go | Moab is renowned for its biological soil crusts, but what’s happening underneath all that crusty black — with the soil and rock itself? This week, we speak with geotechnical engineer Taylor Hall, owner of the Moab Geotechnical Group, about soil mechanics, engineering tools, and how he decided — at age 15, in a McDonald’s — to start working with the dirt. Science Moab: What is geotechnical engineering? Hall: Geotechnical engineering generally deals with rock and soil mechanics and physics: how those materials will respond to structures or just how they respond to gravity. We might look at something like a bridge to understand its foundations, or we might look at a landslide that gets triggered by natural causes. We’re fortunate to be able to come in there and tell you how things are responding and why and what to expect. Science Moab: How do you test soil? Hall: When geotechnical engineering got its feet in the 1940s and 1950s, they would sample soil by drilling a hole and driving a sampler into the ground using a fixed-weight hammer. Using that method, we were able to acquire a sample and get some resistance associated with that sample. That's much of what we do today, but we do it now because it's backed by 60 or 70 years’ worth of empirical relationships. Generally, you're only dealing with one or two such holes, and you have to use them to characterize a whole site. It's tough, but that's why I chose geotechnical engineering: because no two sites are the same. It provides the opportunity to really think on your feet. Science Moab: Once you’ve taken measurements, how do [...]

Researchers in Tasmania design special drill for million year old ice core project

Source: Researchers in Tasmania design special drill for million-year old ice core project to help find answers to climate crisis | The Singleton Argus | Singleton, NSW Answers to the world's climate crisis may be discovered in a 2.8 kilometer pole of million-year-old ice that is set to be extracted from Antarctica and delivered back to research labs in Tasmania for atmospheric testing. Australian Antarctic Division researchers in Tasmania have designed and manufactured a 400-kilogram drill for the million year old ice core project which is capable of operating in minus 55 degree temperatures. It will bore down into 2.8 kilometers of ice, which is believed to be up to 1.5 million years old, to extract three meter sections of ice, or ice core, at any one time. Up to 8 tons of ice will then be brought back to research labs for AAD researchers to extract data and information about past temperatures, sea ice levels and wind patterns in Antarctica. Australian Antarctic Division engineers spent two months preparing blocks of ice that would replicate Antarctic ice, which were then used to test the specially designed drill. Picture: Australian Antarctic Division   It will also be used to answer a "long standing mystery" in Antarctic research about the frequency of ice ages. The project is part of this year's Antarctic research season which has been dubbed the most ambitious season that the AAD have ever undertaken, with 500 scientists and up to 800 tons of cargo to be shipped to Antarctica. Australian Antarctic Division chief scientist Nicole Webster said the million year ice core project is an incredible milestone for climate research. She said layers in the ice core are like "pages in a diary", where tiny air bubbles trapped in the ice core contain atmosphere and other [...]

Himalayan hydropower ‘clean but risky,’ warn scientists

Source: Himalayan hydropower 'clean but risky,' warn scientists With its steep topography and abundant water resources the Himalayas offer sustainable, low-carbon hydropower for energy-hungry South Asia. But there is a catch—the mountain range falls in one of the world's most seismically active regions. A group of 60 top Indian scientists and environmentalists wrote an open letter to Prime Minister Narendra Modi earlier this month seeking his intervention in stopping "any more hydroelectric projects in the Himalayas and on the Ganga whether under construction, new or proposed." The letter cites the Intergovernmental Panel on Climate Change's sixth assessment report which says that the Himalayas have been affected by warming. The report warns that "rising temperature and precipitation can increase the occurrence of glacial lake outburst floods and landslides over moraine-dammed lakes" in high mountain Asia. Moraine consists of rocks and soil left behind by moving glaciers. Hydropower, the world's largest source of renewable electric power with1,308 gigawatts of installed capacity in 2019, is expected to play a critical role in decarbonizing power systems, according to the International Energy Agency (IEA), an inter-governmental body. Stretching 2,400 kilometers in an arc that includes the world's highest peaks, the Everest in Nepal and K2 in Pakistan, the Himalayas rank high among global hot spots for developing hydropower, though only 20 percent of the estimated 500 gigawatt potential has been tapped so far. But that situation is rapidly changing with hydropower projects mushrooming along the Himalayan arc—which covers territory in Bhutan, China, India, Nepal and Pakistan—despite proven risks from quakes, landslides and glacial lake outburst floods. The immediate trigger for the appeal to Modi was a decision by India's Ministry of Environment, Forest and Climate Change to allow the restarting of seven controversial hydropower projects in the Himalayan state of Uttarakhand. Three of these projects—Tapovan-Vishnugad (520 [...]

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 [...]

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 [...]

Sichuan China Earthquake

Source: Sichuan, China: Earthquake leaves three dead and 60 injured - CNN An earthquake in China's southwestern province of Sichuan left at least 3 people dead and 60 injured on September 16th, according to China's state-run media. Local authorities put the quake at 6.0-magnitude, while the US Geological Survey (USGS) put it at 5.4-magnitude on an 8-point scale. The quake hit in the early hours of the morning, with the epicenter located about 52 kilometers (32.3 miles) southwest of Yongchuan district in Chongqing, with an initial depth of 10 kilometers, according to USGS. The earthquake left at least 1,221 collapsed houses and more than 3,000 severely damaged homes, according to the Global Times. "I woke up to the tremor and saw the chandelier in my room swinging dramatically and the writing desk was shaking," one resident, surnamed Tang, told the Global Times. "It's been a long time since an earthquake of this magnitude has occurred." Chinese authorities launched rescue efforts in the morning, with the provincial government activating a level 2 response, the second highest in China's four-tier earthquake emergency response system, according to Xinhua. Luzhou City, home to about five million residents, was among the hard-hit areas. Thousands of soldiers and emergency workers have been sent on rescue efforts, along with rescue equipment, medical supplies, makeshift surgical vehicles and heavy machinery. Tents have been set up for evacuees in a nearby village. Experts say a more serious earthquake is unlikely, though there may be aftershocks, Xinhua reported. Sichuan is located along one of several seismic belts in China, which makes it prone to earthquakes. One local employee in Luzhou told the Global Times that though residents are used to earthquakes, they are usually of a lower magnitude -- and Thursday's quake was much stronger than average. A number of [...]

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

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