Field Investigation of a New Recharge Approach for ASR Projects in Near-Surface Aquifers

Ground Water ◽  
2015 ◽  
Vol 54 (3) ◽  
pp. 425-433 ◽  
Author(s):  
Gaisheng Liu ◽  
Steven Knobbe ◽  
Edward C. Reboulet ◽  
Donald O. Whittemore ◽  
Falk Händel ◽  
...  
Keyword(s):  
Field Investigation ◽  
Near Surface

Subsurface Investigation

2015 ◽  
pp. 744-795
Keyword(s):  
Field Tests ◽  
Field Investigation ◽  
Soil Parameters ◽  
Near Surface ◽  
Ground Investigation ◽  
Geophysical Techniques ◽  
Vertical Profiling ◽  
Sample Recovery ◽  
Subsurface Investigation ◽  
A Site

A good knowledge about a site including its subsurface conditions is very important in its safe and economical development. It is therefore an essential preliminary to the construction of any civil engineering work. This chapter outlines the objectives of site characterization and the general objectives of geotechnical investigation. It discusses the phases of field investigation and the stages of a full exploratory program including methods of sample recovery and field tests and sampling methods. Geophysical techniques can contribute very greatly to the process of ground investigation by allowing an assessment, in qualitative terms, of the lateral variability and vertical profiling of the near-surface materials beneath a site. Some of these geophysical techniques are discussed in the chapter. Laboratory examination/verification and testing should be made of representative portions of the samples to establish appropriate soil parameters. Some soil parameters may be estimated by correlations. The results of the subsurface investigation and related testing, together with interpretations, discussions, and foundation recommendations, are usually presented in the form of a detailed soil report.

scholarly journals Field investigation of Love waves in near‐surface seismology

2007 ◽  
Author(s):  
Robert Eslick ◽  
Georgios Tsoflias ◽  
Don Steeples
Keyword(s):  
Field Investigation ◽  
Love Waves ◽  
Near Surface

Fracture Distribution and Occurrence of DNAPL in a Clayey Lodgement Till

1999 ◽  
Vol 30 (4-5) ◽  
pp. 285-300 ◽  
Author(s):  
Peter Roll Jakobsen ◽  
Knud Erik S. Klint
Keyword(s):  
Preferential Flow ◽  
Surface Sediments ◽  
Coal Tar ◽  
Fracture Network ◽  
Field Investigation ◽  
Horizontal Shear ◽  
Near Surface ◽  
Migration Pathway ◽  
Fracture Systems ◽  
Fracture Distribution

This study examines the spatial fracture network in a clayey lodgement till, and the preferential flow pattern of DNAPL in the till. The study was conducted on a former gasworks site contaminated with coal tar. Fracture analysis was carried out and four fracture systems were recognised. Apart from fractures, burrows and root channels were recorded in the near surface sediments. Field investigation shows that two fracture systems were formed subglacially by loading of a glacier and horizontal shear within the lodgement till. Two other fracture systems were formed subsequently by desiccation and unloading/freeze-thaw processes in the unsaturated zone. Spatial distribution of free-phase DNAPL in the lodgement till is controled by the fracture network. The migration path of the DNAPL through the fracture systems is predominantly vertical in the upper 2 m and horizontal between 2 and 3.5 m. b.s. Below this depth the migration pathway is vertical. DNAPL was visually observed to a depth of 9 m.b.s. within fractures which continued downwards to unknown depth. Upscaling of the fracture properties was performed and a regional fracture model is suggested as a tool in future remidiation.

scholarly journals FULL SCALE NEAR SURFACE WATER PARTICLE VELOCITIES AND PRESSURES ACTING ON AN INCLINED TUBULAR MEMBER

1980 ◽  
Vol 1 (17) ◽  
pp. 113
Author(s):  
Fritz Busching ◽  
Eckehard Martini
Keyword(s):  
Reynolds Numbers ◽  
Wave Force ◽  
Field Investigation ◽  
Velocity Measurements ◽  
Near Surface ◽  
Water Particle ◽  
Wave Kinematics ◽  
Pressure Distributions ◽  
Particle Velocities ◽  
Offshore Wave

A field investigation programme on simultaneous wave force and water particle velocity measurements is decribed with reference to an inclined tubular member subjected to offshore wave kinematics. First measurements at supercritical Reynolds numbers indicate strong irregularities in successively taken pressure distributions on the circumference of the test section as well as in the velocity vectors. The influence of superimposed tidal currents is obvious.

scholarly journals A field investigation of source parameters for the sledgehammer

Geophysics ◽  
1995 ◽  
Vol 60 (4) ◽  
pp. 1051-1057 ◽  
Author(s):  
Dean A. Keiswetter ◽  
Don W. Steeples
Keyword(s):  
Source Parameters ◽  
Peak Frequency ◽  
Field Investigation ◽  
Source Parameter ◽  
Seismic Reflection Data ◽  
Near Surface ◽  
Reflection Data ◽  
Frequency Changes ◽  
Seismic Amplitudes ◽  
Study Sites

We examined amplitude and frequency changes in shallow seismic‐reflection data associated with simple source‐parameter modifications for the sledgehammer. Seismic data acquired at three sites with different near‐surface geology show the potential effects of varying the hammer mass, the hammer velocity, the plate mass, and the plate area. At these study sites, seismic amplitudes depend on plate‐surface area and on hammer mass but not heavily on hammer velocity or plate mass. Furthermore, although the total bandwidth of the recorded data was independent of source parameter changes, the peak frequency at one site was increased approximately 40 Hz by increasing the area of the plate. The results indicate that the effects of modifying the source parameters for the sledgehammer are site‐dependent. The experiments described are quick, cheap, and simple, and can be duplicated by others at prospective sites to answer site‐specific questions.

scholarly journals Field investigation of Love waves in near-surface seismology

Geophysics ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. G1-G6 ◽  
Author(s):  
Robert Eslick ◽  
Georgios Tsoflias ◽  
Don Steeples
Keyword(s):  
Surface Layer ◽  
Data Acquisition ◽  
Love Wave ◽  
Field Data ◽  
Field Investigation ◽  
Love Waves ◽  
Frequency Range ◽  
Minimum Thickness ◽  
Near Surface ◽  
Wave Data

We examine subsurface conditions and survey parameters suitable for successful exploitation of Love waves in near-surface investigations. Love-wave generation requires the existence of a low shear-velocity surface layer. We examined the minimum thickness of the near-surface layer necessary to generate and record usable Love-wave data sets in the frequency range of [Formula: see text]. We acquired field data on a hillside with flat-lying limestone and shale layers that allowed for the direct testing of varying overburden thicknesses as well as varying acquisition geometry. The resulting seismic records and dispersion images were analyzed, and the Love-wave dispersion relation for two layers was examined analytically. We concluded through theoretical and field data analysis that a minimum thickness of [Formula: see text] of low-velocity material is needed to record usable data in the frequency range of interest in near-surface Love-wave surveys. The results of this study indicate that existing guidelines for Rayleigh-wave data acquisition, such as receiver interval and line length, are also applicable to Love-wave data acquisition.

Effects of near-surface environmental conditions on instability of an unsaturated soil slope

2004 ◽  
Vol 41 (6) ◽  
pp. 1111-1126 ◽  
Author(s):  
James A Blatz ◽  
Nelson J Ferreira ◽  
James Graham
Keyword(s):  
Unsaturated Soils ◽  
Field Investigation ◽  
Soil Suction ◽  
Soil Slope ◽  
Flux Boundary Condition ◽  
Near Surface ◽  
Cause Of Failure ◽  
Seepage Modeling ◽  
The Right ◽  
Mechanism Of Failure

In 1999, after a period of extensive rainfall, two shallow slope failures developed in the right-of-way of Provincial Road 259 near Virden, Manitoba. The rainfall caused dissipation of soil suction in the near-surface soil, thereby reducing shear resistance and triggering failure. A research project was initiated between the Geotechnical Group at the University of Manitoba and the Manitoba Department of Highways and Transportation to assess the mechanism of failure. The project included a field investigation program, laboratory testing program, and advanced numerical modeling to identify the cause of failure. The results demonstrate that the rainfall resulted in dissipation of the suction in the soil slope, resulting in a reduction in the soil shear strength that triggered shallow failures. The dissipation of the soil suction has been modeled using a time-dependent seepage model that accounts for the flux boundary condition that existed at the ground surface.Key words: slope stability, unsaturated soils, laboratory tests, soil suction, seepage modeling, flux boundary.

scholarly journals Field investigation of near-surface metamorphism of snow

2011 ◽  
Vol 57 (203) ◽  
pp. 441-452 ◽  
Author(s):  
A.E. Slaughter ◽  
E.E. Adams ◽  
P.J. Staron ◽  
R.H. Shertzer ◽  
D.J. Walters ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Longwave Radiation ◽  
Field Investigation ◽  
Weather Data ◽  
Snow Surface ◽  
Near Surface ◽  
Mean Values ◽  
Facet Formation ◽  
Surface Facet

AbstractBuried surface hoar and near-surface faceted crystals are known to lead to deadly avalanches. Over the course of three winter seasons a field investigation detailing the environmental conditions leading to the formation of these crystals was performed. Weather stations on north- and south-facing aspects were established. The weather data were accompanied by detailed daily observations and grain-scale photographs of the snow surface. During the three seasons, 35 surface hoar and 47 near-surface facets events were recorded. The mean weather conditions for the entire dataset (all three seasons and both stations) were compared to the nights when surface hoar formed. The comparison yielded five parameters that were statistically linked to the formation of surface hoar: incoming longwave radiation, snow surface temperature, wind velocity, relative humidity and the air/snow temperature difference. A similar comparison between the daytime mean values for all days with near-surface facet events revealed three parameters with statistically significant differences. Thus, these parameters (short- and longwave radiation and relative humidity) could be statistically linked to facet formation. This research also suggests that environmental conditions in the daytime hours before and after surface hoar formation are statistically similar to the conditions causing near-surface facet formation.

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

1991 ◽  
Vol 49 ◽  
pp. 870-871
Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter
Keyword(s):  
Colony Growth ◽  
Dark Field ◽  
Dark Side ◽  
Silicide Phase ◽  
Strain Fields ◽  
Near Surface ◽  
Unknown Composition ◽  
Secondary Precipitates ◽  
20 Nm ◽  
2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

Sign in / Sign up

Export Citation Format

Share Document