A5078452731- Geophysical Methods and Applications
- Seismic Waves and Analysis
- Geotechnical Engineering and Soil Mechanics
- Geotechnical Engineering and Soil Stabilization
- Geotechnical Engineering and Underground Structures
- Seismic Imaging and Inversion Techniques
- Advanced Fiber Optic Sensors
- Geophysical and Geoelectrical Methods
- Geophysics and Sensor Technology
- Soil and Unsaturated Flow
- Seismology and Earthquake Studies
- Soil Moisture and Remote Sensing
- Underwater Acoustics Research
- Geological Modeling and Analysis
- Structural Health Monitoring Techniques
- Rock Mechanics and Modeling
- Geotechnical and construction materials studies
- Geotechnical and Geomechanical Engineering
- Landslides and related hazards
- Soil Mechanics and Vehicle Dynamics
- Grouting, Rheology, and Soil Mechanics
- Hydrocarbon exploration and reservoir analysis
- Photonic and Optical Devices
- Granular flow and fluidized beds
- Concrete Corrosion and Durability
University of Wisconsin–Madison
2015-2024
University of Wisconsin System
2013-2018
Golder Associates (United States)
2010
Louisiana State University
2000-2009
Geosyntec Consultants (United States)
2009
ExxonMobil (United States)
2009
Georgia Institute of Technology
1996-2005
University of Hong Kong
2005
University of Waterloo
2005
University of Toronto
2005
The PoroTomo research team deployed two arrays of seismic sensors in a natural laboratory at Brady Hot Springs, Nevada March 2016. 1500 m (length) × 500 (width) 400 (depth) volume the overlies geothermal reservoir. distributed acoustic sensing (DAS) array consisted about 8400 fiber-optic cable shallow trench and 360 well. conventional seismometer 238 shallowly buried three-component geophones. DAS was laid out three parallel zig-zag lines with line segments approximately 100 length geophones...
Abstract A field test that was conducted at Garner Valley, California, on 11 and 12 September 2013 using distributed acoustic sensing (DAS) to sense ground vibrations provided a continuous overnight record of ambient noise. The energy noise concentrated between 5 25 Hz, which falls into the typical traffic frequency band. standard procedure (Bensen et al. , 2007) adopted calculate cross‐correlation functions (NCFs) for 1‐min intervals. 1‐min‐long NCFs were stacked time–frequency domain...
This introductory book presents procedures for the analysis of signals and characterization systems in civil engineering. The two main topics this are at core several fast-growing areas engineering today, including: non-destructive testing, system identification, image processing, local or remote monitoring, smart structures, dynamic loading, feedback control transportation structural authors have provided readers with a Web site dedicated to which includes readily downloadable algorithms...
Gas hydrate-bearing sediments recovered by pressure coring from the Krishna−Godavari Basin offshore India during 2006 National Hydrate Program (NGHP) expedition were characterized using instrumented testing chamber (IPTC). The IPTC studies provided longitudinal profiles of P- and S-wave velocities, electrical conductivity, undrained penetration resistance. formation consisted fine-grained clayey high specific surface plasticity. X-ray images showed horizontal layering, pronounced...
Research Article| August 08, 2018 Active‐Source Seismic Tomography at the Brady Geothermal Field, Nevada, with Dense Nodal and Fiber‐Optic Arrays L. M. Parker; Parker aDepartment of Geoscience, University Wisconsin‐Madison, Madison, Wisconsin 53706 U.S.A., cthurber@wisc.edu Search for other works by this author on: GSW Google Scholar C. H. Thurber; Thurber X. Zeng; Zeng bState Key Laboratory Geodesy Earth’s Dynamics, Institute Geophysics, Chinese Academy Sciences, Wuhan 430077, China P. Li;...
We analyze interferometric synthetic aperture radar (InSAR) data acquired between 2004 and 2014, by the ERS-2, Envisat, ALOS TerraSAR-X/TanDEM-X satellite missions to measure characterize time-dependent deformation at Brady Hot Springs geothermal field in western Nevada due extraction of fluids. The long axis ∼4 km ∼1.5 elliptical subsiding area coincides with strike dominant normal fault system Brady. Within this bowl subsidence, interference pattern shows several smaller features length...
At Brady Hot Springs, a geothermal field in Nevada, heated fluids have been extracted, cooled, and re-injected to produce electrical power since 1992. Analysis of daily pumping records catalogs microseismicity between 2010 2015 indicates statistically significant correlation days when the volume production was at or above its long-term average rate no seismic event detected. Conversely, shutdowns for plant maintenance correlate with increased microseismicity. We hypothesize that effective...
Abstract Monitoring ground motion in smart cities can improve the public safety by providing critical insights on natural and anthropogenic hazards, for example, earthquakes, landslides, explosions, infrastructure failures, so forth. Although seismic activity is typically measured using dedicated point sensors (e.g., geophones accelerometers), techniques such as distributed acoustic sensing have demonstrated utility of fiber-optic cable to detect over comparable distances. In this article,...
The mechanical characteristics and orientation of joints determine the behaviour rock masses, including strength, stiffness, all forms conduction diffusion. Furthermore, preferential renders medium anisotropic. In turn, these properties affect velocity damping propagating elastic waves. purpose this study is to investigate propagation long-wavelength shear waves through a mass with open filled softer gouge, subjected low confinement. These conditions are selected in view near-surface...
Abstract This paper summarizes a new nondestructive approach for the evaluation of soil density and water content. measurement methodology involves evaluating dielectric permittivity P-wave velocity in soils as content is increased. These values are then related to volumetric content, porosity, skeleton shear stiffness, which needed back-calculate tested specimens. Experimental laboratory results briefly summarized. test show potential developing device. Electronic equipment sensors proposed...
The mechanical performance of pavement systems depends on the stiffness subsurface soil and aggregate materials. moduli base course, subbase, subgrade soils included in need to be characterized for their use new empirical-mechanistic design procedure (NCHRP 1-37A). Typically, resilient modulus test is used subbase layers under repetitive loads. Unfortunately, tests are expensive cannot applied materials that contain particles larger than 25 mm (for 125-mm diameter specimens) without scalping...
A vibration-sensitive, Distributed Acoustic Sensor (DAS) array, using fiber-optic cables, was deployed in a triangularly shaped geometry on the frozen surface of Lake Mendota Madison, Wisconsin, USA. The purpose array and testing program to analyze DAS response utilize high spatial density distributed for system characterization well-constrained, small, array. geophone also provide reference system. design allowed us assess with respect distance from seismic sources, degradation length...
Abstract This paper presents a new apparatus for the measurement of P and S-wave velocities in unsaturated soil specimens under controlled net stress matric suction conditions. The system consists triaxial cell modified to enable an independent control pore air water pressures as well confining pressure, accommodate sources receivers. also includes three servo-controlled pressure pumps, computer that drives acquires volume changes. Three sets experiments were conducted verify performance....
This paper presents the results of capillary pressure and electrical resistivity measurements for three kinds core specimens: Berea sandstone, Quartz Limestone. Experimental data index, formation factor, tortuosity, pressure, water saturation exponent in air/brine system these cores are reported. The resistivities evaluated using modified Archie's law. Capillary versus brine show existence two irreducible saturations corresponding to different physical phenomena. values yield upper lower...
The longevity of a pavement system is closely related to the amount deformation both asphalt surface and underlying layers. Placing geogrid in granular base decreases rutting at by providing some strength increasing stiffness thus limiting elastic deformations loads transmitted sub-grade. However, zone influence layer on surrounding soil particles increase modulus this are not well known. A testing scheme aimed quantifying caused presence materials was developed. Both P-wave velocity shear...
The paper presents the results of an experimental investigation fine particle migration from pore body to throat and toward contact between particles its effect on skeleton stiffness granular materials. We hypothesize that suspended colloids in fluid migrate deposit surface skeleton-forming change magnitude soil stiffness. Three specimens were prepared using uniform spherical glass saturated with deionized water kaolinite or silt-base slurries. drained by evaporation which retained fines...
Between 1980 and 2008, traffic on Class 1 railroads has increased 93% total track length decreased 42%, leading to a substantial increase in density maintenance requirements. To improve techniques for problematic rail infrastructure elements (e.g., bolted joints, intersections, bridge approaches, etc.), method of reinforcing ballast layers using rigid polyurethane been developed. Laboratory tests polyurethane-stabilized (PSB) shows that strength resistance permanent deformation is higher...