Source: DVIDS - News - Geologists and Geotechnical engineers dig deep to provide flood risk management At the Arcadia flood risk management project, in Arcadia, Wisconsin, geotechnical staff are gathering data using a unique method of subsurface exploration. The Cone Penetrometer Test, or CPT, is one method used to identify and characterize soils. The CPTs were conducted with assistance from the Savannah District geotechnical and geology branch. “We benefited from their expertise and cooperation,” said Greg Wachman, senior geotechnical engineer. In CPTs, a device with a conical tip and metal sleeve measure penetration resistance as it’s pushed into the ground. Those measurements are used to characterize the soils’ engineering properties. For example, the forces on the device as it’s pushed through a soft clay are very different from those as it’s pushed through a dense sand, Wachman said. The device also records pore water pressure, which aids in understanding soil permeability and groundwater characteristics. CPTs vs. soil borings A CPT is most useful when used together with standard soil borings, Wachman explained. A soil boring drills into the ground to retrieve physical samples. In contrast, with a CPT, the soil is never seen. CPTs are significantly faster than standard borings and provide continuous test data with depth. With a soil boring, samples are collected about every 5 feet, or change in material, so it’s possible to miss important information. One limitation of the CPT, due to excessive friction, is that it may not be extended to the same depth as a soil boring. The CPTs at Arcadia are being pushed to approximately 60-70 feet, whereas a soil boring can be performed in excess of 100 feet. “By doing some CPTs next to soil borings – where we know what the soils are – we can increase the likelihood that we [...]
Source: South Dakota Homeowners Sue County Over Sinkhole Risks More than 150 homeowners in a development outside Rapid City, South Dakota, are suing Meade County over risks to their properties after a sinkhole exposed an abandoned gypsum mine. The federal complaint filed Sept. 27 by Hideaway Hills residents in Black Hawk seeks damages to be determined by a jury and other relief “allowed by law or equity.” The sinkhole forced about 40 residents from 15 homes in April 2020. Geotechnical studies show there could be water flowing through the abandoned mine and toward Interstate 90 and there is the potential for future sinkholes, the Rapid City Journal reported. The complaint alleges several violations of the state Constitution. It says the decision to approve the subdivision by the county Planning Commission and the Meade County Commission put homeowners at risk. “Without the decisions to approve the subdivision, issue building permits and certificates of occupancy, the opportunity for harm would not have existed,” the complaint states. Developers allegedly informed the county in 2001 of an underground gypsum mine and discussed taking steps to determine if it was safe to build on. The commission approved the subdivision proposal in 2003. Katelyn Cook, an attorney for the county, said her legal team does not comment on pending litigation. South Dakota isn't the only area that suffers from sinkholes. Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania tend to have the most damage from sinkholes.
Source: Lancaster County sinkhole raises concern over detours, emergency responder response times | WHP LANCASTER COUNTY, Pa. — A nearly 20-foot sinkhole on State Route 324 (Marticville Road) between Sprecher Road and West Penn Grant Road in Lancaster County is causing detours for community members and concern over delays for emergency responders. PennDOT implemented a detour Sunday night, originally anticipating work to fill the sinkhole would begin in a month. PennDOT Engineering District 8 Press Officer Dave Thompson exclusively tells CBS 21 News’ Samantha York Thursday the timeline has extended. “We expect this road might be closed into next spring before we can actually start working on it,” Thompson says. “That’s- that’s news to me,” New Danville Fire Company Fire Chief Brad Shenk says. 20% of his 25 active volunteer firefighters live on the opposite side of the sinkhole and respond to emergencies from home in a rural town. He says being delayed for a few minutes can make a big difference when time is of the essence, requesting the sinkhole to be filled sooner. “It’s going to have an adverse effect on our response times to get those members here,” Shenk tells CBS 21’s Samantha York. “We’re a small fire company, we’re counting on everybody to go up at any given time, whoever’s available responds and these guys are going to be delayed by several minutes.” Community members speculate the sinkhole, which reaches from the middle of the road through a drainage ditch and into adjacent property, has something to do with new construction nearby. However, the cause remains undetermined by officials – which is causing the delay in getting it fixed. “We’ve assessed what needs to be done, but we need to get some- an agreement in place with a local property owner that’s property is adjacent to [...]
Source: Breakwaters aim to halt ongoing erosion at coastal refuge | ASCE Although the new breakwaters were primarily intended to stop erosion, sediment is already building up behind the barriers as a side benefit. (Courtesy of CPRA) A series of breakwaters to protect a coastal wildlife refuge in southwestern Louisiana incorporated an innovative, lightweight design. Despite extremely poor soils and ongoing erosion that kept changing the shoreline throughout the project, the breakwaters are already showing dramatic results. The Rockefeller Wildlife Refuge in southwestern Louisiana, which borders the Gulf of Mexico for 26.5 mi, is disappearing at an increasingly rapid rate. The Gulf of Mexico has shores on Texas, Mississippi, Alabama, and Florida. When it was created in 1920, the refuge originally encompassed 86,000 acres of biologically diverse coastal wetlands in Cameron and Vermillion Parishes. But over time, ongoing coastal erosion has reduced the refuge to 71,000 acres. Twenty years or so ago, a key 9.2 mi stretch of the refuge was losing about 50 ft of land per year, notes Phillip “Scooter” Trosclair III, a biologist program manager for the Louisiana Department of Wildlife and Fisheries, which manages the refuge. The rate of loss in that region increased to around 70 ft a year, then 100 ft, and then by 2016 surveys indicated that more than 300 ft of land had disappeared in a single year, Trosclair says. People worried that “if we keep getting hit with this pattern, we’re not going to have any land left,” Trosclair recalls. But even as the refuge seemed in greater danger, a solution was already in the works. When erosion losses started to accelerate around 2000, the Rockefeller Refuge Gulf Shoreline Stabilization Project was taking shape. Implemented by the Louisiana Coastal Protection and Restoration Authority and the National Marine Fisheries Service [...]
Source: International Conference on Earthquake Geotechnical Engineering ICEGE in February 2023 in Paris The International Research Conference Aims and Objectives The International Research Conference is a federated organization dedicated to bringing together a significant number of diverse scholarly events for presentation within the conference program. Events will run over a span of time during the conference depending on the number and length of the presentations. With its high quality, it provides an exceptional value for students, academics and industry researchers. International Conference on Earthquake Geotechnical Engineering aims to bring together leading academic scientists, researchers and research scholars to exchange and share their experiences and research results on all aspects of Earthquake Geotechnical Engineering. It also provides a premier interdisciplinary platform for researchers, practitioners and educators to present and discuss the most recent innovations, trends, and concerns as well as practical challenges encountered and solutions adopted in the fields of Earthquake Geotechnical Engineering Call for Contributions Prospective authors are kindly encouraged to contribute to and help shape the conference through submissions of their research abstracts, papers and e-posters. Also, high quality research contributions describing original and unpublished results of conceptual, constructive, empirical, experimental, or theoretical work in all areas of Earthquake Geotechnical Engineering are cordially invited for presentation at the conference. The conference solicits contributions of abstracts, papers and e-posters that address themes and topics of the conference, including figures, tables and references of novel research materials. Guidelines for Authors Please ensure your submission meets the conference's strict guidelines for accepting scholarly papers. Downloadable versions of the check list for Full-Text Papers and Abstract Papers. Please refer to the Paper Submission Guideline, Abstract Submission Guideline and Author Information before submitting your paper. Conference Proceedings All submitted conference papers will be blind peer reviewed by three competent reviewers. The peer-reviewed conference proceedings are indexed in the Open Science Index, Google Scholar, Semantic Scholar, Zenedo, OpenAIRE, BASE, WorldCAT, Sherpa/RoMEO, and [...]
Source: UNF first in Florida to conduct large-scale l | EurekAlert! Jacksonville, Fla. – University of North Florida researchers will be the first in Florida to conduct large-scale laboratory testing of sinkhole mechanics. Dr. Ryan Shamet, civil engineering assistant professor, was recently awarded a Florida Department of Transportation project grant for “Validation and Update of the Sinkhole Index,” a project that will aim to better understand the potential of sinkhole formation prior to any collapse at the surface. This joint project between UNF and University of Central Florida includes $90,259 for UNF and new equipment coming to UNF labs. The new equipment consists of a large-scale soil box that will allow UNF researchers to recreate and monitor the geotechnical and hydraulic mechanics of sinkholes forming in north and central Florida. The researchers at UNF and UCF will collect data from active sinkhole sites throughout the state and then refine and update analysis techniques for varying geologic conditions or regions based on their data. This analysis technique will allow engineers to quantify a location’s relative vulnerability of conditions favorable to sinkhole collapse when raveling conditions are encountered using an investigation test called the Cone Penetration Test (CPT). CPTs are a common subsurface investigation tool used by geotechnical engineers to identify soil layers and measure the strength of the soil within a project location. Through quantifying the raveling phenomenon, local engineers can better discern which mitigation techniques, such as compaction grouting or road closure, should be performed to lower the associated risk of sinkhole collapse.
Source: Soil Nail Walls - Design and Construction -NEW (7003IW2022) INSTRUCTOR: Naresh Samtani, Ph.D., P.E., D.GE, F.ASCE Participants will have access to the virtual workshop video archives and materials for 60 days from the start day of the workshop. Virtual Workshop Brief Using a collaborative and interactive learning approach, this virtual workshop will help you understand the design and construction aspects for soil nail walls. You will learn newer design approaches based on the LRFD platform that is the basis for guidelines for soil nail walls by the American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration (FHWA). The workshop will help you assimilate the design and construction aspects through active participation by frequent interactions throughout the workshop and real-time expert feedback. The interactions will facilitate a better understanding of the nuances of the newer design principles which would help you avoid costly design errors in real-world projects. In between the two live sessions, attendees will independently work on an application (e.g., exercises) or a reflection (e.g., reading) assignment. Learning Outcomes Upon completion of this course, you will be able to: Explain the terminology for soil nail walls Explain design of soil nail walls using principles of limit state design Explain the essential elements of construction Recognize construction procedures and influence on wall design and performance Explain the importance and concepts of nail testing Identify necessary characteristics of software tools Explain corrosion considerations Discuss facing (shotcrete) analysis Identify the necessary information on plans and specifications Benefits for Participants Become familiar with the latest limit state design approaches and standards for soil nail walls Avoid common pitfalls and costly errors in analysis and design Be able to categorize and streamline limit state evaluation Recognize the importance of considering construction as part of overall design process Assessment of [...]
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 [...]
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 [...]
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 [...]