December 2021 - GEOTILL provides geotechnical, construction testing and Environmental services Indianapolis Indiana

Researcher Aids Arkansas Highway Projects Through Subsurface Analysis

Source: Researcher Aids Arkansas Highway Projects Through Subsurface Analysis | University of Arkansas FAYETTEVILLE, Ark. – A University of Arkansas geotechnical engineer is collaborating with the Arkansas Department of Transportation to map subsurface conditions before road construction begins to identify issues early and help keep highway construction projects on track and on budget. Clint Wood, a civil engineering associate professor and geotechnical engineer, creates profiles of subsurface conditions and soil composition by sending stress waves into the ground and measuring their response at the surface. The non-invasive technology is similar to how ultrasound imaging works on the human body. The technology provides important information for highway designers and construction contractors, who’ve had to rely on imperfect methods for determining subsurface conditions, such as exploratory drilling, a strategy that can miss changes between limited drilling locations. Wood compares designing based on limited exploratory drilling to navigating with an incomplete map. The research is conducted for and in conjunction with the Arkansas Department of Transportation. With an additional $115,318 grant, the transportation department has provided a total of $561,427 in funding. The work focuses on estimating the depth and stiffness of bedrock for new highway alignments and understanding subsurface conditions that cause slope instability. The latter is especially important for understanding how water moves through a slope. Unexpected changes in bedrock depth near slopes can also create pockets where water collects, which can cause the soil in the slope to become saturated, leading to instability. Projects that encounter these issues can face substantial extra costs and delays while designers and contractors adapt the original plan or have to attempt another repair. Those problems can be avoided, or at least minimized, by better understanding the subsurface conditions through non-invasive testing. LIDAR AND DRONE ACCURACY In a separate project, Wood and several other U of A [...]

By kk42|December 13th, 2021|Geotechnical Illinois, Geotechnical Michigan, Geotechnical Missouri, Geotechnical Minnesota, Geotechnical Kansas, Geotechnical Arkansas|0 Comments

Geologists and Geotechnical engineers provide flood risk management

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 [...]

By kk42|December 13th, 2021|Geotechnical California, Geotechnical Texas, Geotechnical Wisconsin, Geotechnical Florida, CPT Blog, CPT Data, Cone Penetration, Geotechnical Arizona|0 Comments

Long-Term Testing Of Concrete Bond Durability

Source: Long-Term Testing Of Concrete Bond Durability The definition of concrete durability can be explained as the ability of a specimen to resist any form of weathering action, namely abrasion, chemical, physical, or any other process of deterioration. In other words, the durability of concrete can also be defined as the ability to last a long period of time without significant deterioration or failure. Image Credit: Peshkova/Shutterstock.com Types of weathering include mechanical, physical, and chemical weathering of concrete including the alkali-aggregate reaction of sulfate attack and chloride attack. Different long-term testing methods have been used over the years and more research has been done to improve the existing methods to be more economical and environmental. Consideration has also gone into methods that reduce the time in which these tests can be completed and assessed. The Importance Of Long-Term Durability Testing It is important to test for the durability of concrete bonds because of the following reasons. Firstly, concrete testing will allow the designers to determine accurately the lifespan of a specific structure according to its specific needs or requirements. If a structure is intended to last a specific period of time, long-term concrete testing can reveal the combination that is required for it to last that long. There can be economic and environmental benefits to this testing. Economically, constant rehabilitation and patching up of structures are very expensive. Hence, long-term testing can reveal the right combination of concrete mixtures for durable structures, thereby reducing the number of times for rehabilitation. Environmentally, constant rehabilitation will require more use of natural resources such as sources of energy, gypsum, or steel to continuously rehabilitate worn-out structures. Continued rehabilitation increases the carbon footprint, which is not environmentally friendly. Developments In Concrete Bond Materials New studies have revealed that the addition of carbon fibers amounting [...]

By kk42|December 10th, 2021|Geotechnical Services, Geotechnical California, Geotechnical Colorado, Geotechnical New York, Geotechnical Texas|0 Comments

Monthly Archives: December 2021

Researcher Aids Arkansas Highway Projects Through Subsurface Analysis

Geologists and Geotechnical engineers provide flood risk management

Long-Term Testing Of Concrete Bond Durability