The Application of Near-Surface Geophysics at Proposed Pipeline River Crossings: A Comparative Overview of Various Techniques and Their Associated Capabilities and Limitations

2002 ◽  
Author(s):  
Paul Tarrant ◽  
David Baines
Keyword(s):  
Large Diameter ◽  
Seismic Refraction ◽  
Directional Drilling ◽  
Near Surface ◽  
Design Engineers ◽  
Geotechnical Investigations ◽  
Geophysical Surveys ◽  
Ground Conditions ◽  
Borehole Drilling ◽  
Near Surface Geophysics

The cost, design, and in some instances, feasibility of directional drilling large diameter or lengthy pipeline river crossings is primarily dependent on ground conditions encountered during construction. Geotechnical investigations are commonly used to explore and assess subsurface conditions at proposed crossings. Ground conditions are determined using borehole drilling and near surface geophysics. Borehole drilling provides subsurface sediment stratigraphy and depth to bedrock information. Geophysics is used to provide information between borehole locations or where borehole drilling is determined to be too difficult or too costly. When used to augment borehole results, geophysical surveys provide more complete geologic cross-section models throughout the length of a proposed directional drill path. This paper presents an overview of the more common geophysical methodologies used to profile subsurface conditions at proposed pipeline crossings. The methods discussed include ground penetrating radar (GPR), seismic refraction profiling and electrical resistivity tomography (ERT). The appropriateness and feasibility of each method is discussed in terms relating to investigation objectives of geotechnical and pipeline design engineers. All three methods were applied to two survey lines at a typical river crossing site on the Bow River, downstream from Calgary, Alberta. Results from the overlapping surveys are presented and the capabilities and limitations for each method compared. Borehole information obtained within the survey area is used to corroborate the interpreted geophysical results.

Current Land and Waterborne Geophysical Methods for Guiding Horizontal Directional Drilling and Trenching Along Pipeline Right-of-Ways

2016 ◽  
Author(s):  
Paul Bauman ◽  
Alastair McClymont ◽  
Landon Woods ◽  
Erin Ernst
Keyword(s):  
Seismic Refraction ◽  
Geophysical Methods ◽  
Cost Effective ◽  
The Arctic ◽  
Directional Drilling ◽  
Borehole Geophysics ◽  
Discontinuous Permafrost ◽  
Refraction Seismic ◽  
Geotechnical Investigations ◽  
Geophysical Surveys

In Western Canada, oil and natural gas pipeline projects are being considered that will move hydrocarbons from the Prairie Provinces and British Columbia, to the Pacific Ocean, the Atlantic, and even potentially the Arctic. Along the proposed right-of-ways, the pipeline engineers will encounter challenging and varied terrain, including discontinuous permafrost, creek and river crossings, glaciomarine clays, thick muskeg, and other subsurface conditions that require specialized engineering planning in advance of construction. Geophysical surveys, in support of geotechnical investigations, provide continuous subsurface information to help inform design challenges associated with the many terrain challenges. Some geophysical surveys to be considered include electrical resistivity tomography (ERT), induced polarization (IP), seismic refraction, seismic reflection, multi-channel analysis of surface waves (MASW), ground penetrating radar (GPR), and borehole geophysics. Typically, a combination of several geophysical surveys along with drilling information, are optimal for the cost-effective site characterization of problematic segments of proposed pipeline right-of-ways.

scholarly journals Subsurface characterization of a quick-clay vulnerable area using near-surface geophysics and hydrological modelling

Solid Earth ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 1685-1705
Author(s):  
Silvia Salas-Romero ◽  
Alireza Malehmir ◽  
Ian Snowball ◽  
Benoît Dessirier
Keyword(s):  
Large Scale ◽  
Geophysical Methods ◽  
Hydrological Modelling ◽  
P Wave ◽  
Coarse Grained ◽  
Near Surface ◽  
Reflection Seismic ◽  
Geotechnical Investigations ◽  
Quick Clay ◽  
Near Surface Geophysics

Abstract. Quick-clay landslides are common geohazards in Nordic countries and Canada. The presence of potential quick clays is confirmed using geotechnical investigations, but near-surface geophysical methods, such as seismic and resistivity surveys, can also help identify coarse-grained materials associated with the development of quick clays. We present the results of reflection seismic investigations on land and in part of the Göta River in Sweden, along which many quick-clay landslide scars exist. This is the first time that such a large-scale reflection seismic investigation has been carried out to study the subsurface structures associated with quick-clay landslides. The results also show a reasonable correlation with radio magnetotelluric and travel-time tomography models of the subsurface. Other ground geophysical data, such as high magnetic values, suggest a positive correlation with an increased thickness of the coarse-grained layer and shallower depths to the top of the bedrock and the top of the coarse-grained layer. The morphology of the river bottom and riverbanks, e.g. subaquatic landslide deposits, is shown by side-scan sonar and bathymetric data. Undulating bedrock, covered by subhorizontal sedimentary glacial and postglacial deposits, is clearly revealed. An extensive coarse-grained layer (P-wave velocity mostly between 1500 and 2500 m s−1 and resistivity from approximately 80 to 100 Ωm) exists within the sediments and is interpreted and modelled in a regional context. Several fracture zones are identified within the bedrock. Hydrological modelling of the coarse-grained layer confirms its potential for transporting fresh water infiltrated in fractures and nearby outcrops located in the central part of the study area. The modelled groundwater flow in this layer promotes the leaching of marine salts from the overlying clays by seasonal inflow–outflow cycles and/or diffusion, which contributes to the formation of potential quick clays.

High resolution GPR investigations employing single and multichannel systems in the Necropolis of Monte Abatone, Cerveteri (Roma, Italy).

2020 ◽  
Author(s):  
Salvatore Piro ◽  
Bruna Malandruccolo
Keyword(s):  
Ground Penetrating Radar ◽  
Landscape Archaeology ◽  
Dual Frequency ◽  
Near Surface ◽  
Complete Mapping ◽  
Geophysical Surveys ◽  
Near Surface Geophysics ◽  
Anomalous Bodies ◽  
And Migration ◽  
Ground Penetrating

<p>The Monte Abatone Necorpolis is one of the main important necropolis of Cerveteri, located 60 km north of Rome (Latium, Italy). In this area, several tombs have been discovered and excavated from the 1800, though still many remain hidden underneath the subsurface.</p><p>In the last two years, geophysical surveys have been carried out to investigate the unexplored portions of the ancient Etruscan Necropolis, to provide a complete mapping of the position of the tombs. Ground Penetrating Radar and the Magnetometric methods have been used during 2018 to investigate few parts of the Necropolis. During 2019 (July and September) GPR system SIR 3000 (GSSI), equipped with a 400 MHz antenna with constant offset, SIR4000 (GSSI) equipped with a dual frequency antenna with 300/800 MHz and the 3D Radar Geoscope multichannel stepped frequency system were employed to survey 5 hectares where the presence of tombs was hypothesized from previous archaeological studies.</p><p>All the GPR profiles were processed with GPR-SLICE v7.0 Ground Penetrating Radar Imaging Software (Goodman 2017). The basic radargram signal processing steps included: post processing pulse regaining; DC drift removal; data resampling; band pass filtering; background filter and migration. With the aim of obtaining a planimetric vision of all possible anomalous bodies, the time-slice representation technique was applied using all processed profiles showing anomalous sources up to a depth of about 2.5 m.</p><p>The preliminary obtained results clearly show the presence of a network of strong circular features, linked with the buried structural elements of the searched tombs.</p><p>Together with archaeologists, these anomalies, have been interpreted to have a better understanding of the archaeological definition of these features and to enhance the knowledge of the necropolis layout and mapping; after the geophysical surveys, excavations have been conducted, which brought to light few of the investigated structures.</p><p> </p><p><strong>References</strong></p><p>Campana S., Piro S., 2009. Seeing the Unseen. Geophysics and Landscape Archaeology. Campana & Piro Editors. CRC Press, Taylor & Francis Group. Oxon UK, ISBN 978-0-415-44721-8.</p><p>Goodman, D., Piro, S., 2013. GPR Remote sensing in Archaeology, Springer: Berlin.</p><p>Piro S., Papale E., Zamuner D., Kuculdemirci M., 2018. Multimethodological approach to investigate urban and suburban archaeological sites. In “Innovation in Near Surface Geophysics. Instrumentation, application and data processing methods.”, Persico R., Piro S., Linford N., Ed.s. pp. 461 – 504, ISBN: 978-0-12-812429-1, pp.1-505, Elsevier.</p>

Geostatistical simulation for geophysical applications—Part II: Geophysical modeling

Geophysics ◽  
1990 ◽  
Vol 55 (11) ◽  
pp. 1441-1446 ◽  
Author(s):  
P. N. Shive ◽  
T. Lowry ◽  
D. H. Easley ◽  
L. E. Borgman
Keyword(s):  
Physical Properties ◽  
Seismic Velocity ◽  
Seismic Refraction ◽  
Three Dimensional ◽  
Companion Paper ◽  
Geostatistical Simulation ◽  
Near Surface ◽  
Geophysical Modeling ◽  
Karst Environment ◽  
Geophysical Surveys

A companion paper (this issue) describes a method for producing three‐dimensional simulations of physical properties for different geologic situations. Here we create a simulation for a particular case, which is a near‐surface (<80 ft deep) description of a karst environment. We simulate seismic velocity, density, resistivity, and the dielectric constant for this situation. We then conduct (in the computer) hypothetical geophysical surveys at the surface of the model. These surveys are seismic refraction, microgravity, dc resistivity, and ground‐probing radar. Physical properties appropriate for cavities are then entered in the model. Repeating the geophysical surveys over the model with cavities provides a convenient method of evaluating their potential for cavity detection. Anomalies produced by normal variations in physical properties may simulate or obscure anomalies from target features. More data about the correlation of physical properties, particularly in the horizontal directions, will be required to evaluate this problem properly.

scholarly journals Geophysical site assessment of an active urban development site, southeastern suburb of Cairo, Egypt

2020 ◽  
Vol 54 (1) ◽  
pp. qjegh2018-151
Author(s):  
N. I. Medhat ◽  
M. Atya ◽  
E. A. Ragab ◽  
A. A. El-Kenawy ◽  
M. Abdel Zaher ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Structural Damage ◽  
Residential Buildings ◽  
Seismic Refraction ◽  
Urban Site ◽  
Site Assessment ◽  
Near Surface ◽  
Geophysical Surveys ◽  
Quarry Blasting ◽  
Ground Stability

There has been significant structural damage of newly built residential buildings in Quarter-27 District in the SE of Cairo, Egypt. A nearby active limestone quarry may also be affecting ground stability. This paper shows how a near-surface geophysical survey could characterize the site, unusually after the initial housing construction had already been undertaken. Geophysical surveys included seismic refraction (acquired between phases of quarry blasting), electrical resistivity and ground penetrating radar (GPR) 1D and 2D datasets. Geophysical results produced maps of a 3D ground model that also included water table depth, known major faults and a saturated layer that may have caused the building damage. Of the geophysical techniques trialled electrical resistivity tomography and GPR data were deemed optimal. This study shows that it is possible to undertake geophysical surveys to characterize a restricted urban site development.

scholarly journals Beyond Never-Never Land: Integrating LiDAR and Geophysical Surveys at the Johnston Site, Pinson Mounds State Archaeological Park, Tennessee, USA

2020 ◽  
Vol 12 (15) ◽  
pp. 2364 ◽  
Author(s):  
Edward R. Henry ◽  
Alice P. Wright ◽  
Sarah C. Sherwood ◽  
Stephen B. Carmody ◽  
Casey R. Barrier ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Middle Woodland ◽  
Near Surface ◽  
Geophysical Surveys ◽  
Social Landscape ◽  
History Of ◽  
Near Surface Geophysics ◽  
Social Landscapes ◽  
Human Landscape ◽  
Made In

Archaeologists often use near-surface geophysics or LiDAR-derived topographic imagery in their research. However, rarely are the two integrated in a way that offers a robust understanding of the complex historical palimpsests embedded within a social landscape. In this paper we present an integrated aerial and terrestrial remote sensing program at the Johnston Site, part of the larger Pinson Mounds landscape in the American MidSouth. Our work at Johnston was focused on better understanding the history of human landscape use and change so that we can begin to compare the Johnston Site with other large Middle Woodland (200 BC–AD 500) ceremonial centers in the region. Our research allowed us to examine the accuracy of an early map of the Johnston Site made in the early 20th century. However, our integrated remote sensing approach allows us to go well beyond testing the usefulness of the map; it helps identify different uses of the site through time and across space. Our research emphasizes the importance of an integrated remote sensing methodology when examining complex social landscapes of the past and present.

scholarly journals Characterization of carbonate rocks using seismic wave for tunnel design stability

2021 ◽  
Vol 325 ◽  
pp. 03002
Author(s):  
Hairin Taha ◽  
Nurul Atiqah Dzulkifli ◽  
Rohayu Che Omar ◽  
Ratih Fitria Putri ◽  
Rasyikin Roslan ◽  
...  
Keyword(s):  
Wave Velocity ◽  
Carbonate Rocks ◽  
Dynamic Properties ◽  
Seismic Refraction ◽  
P Wave ◽  
Sound Waves ◽  
Geotechnical Investigations ◽  
Geophysical Surveys ◽  
Tunnel Design ◽  
Primary Velocity

The design and construction of a tunnel depends on the mechanical properties of the rock mass around the tunnel. Seismic method can be used to characterize the dynamic properties of rocks. The technique is mostly conducted in geophysical surveys and geotechnical investigations. The method utilizes reflected sound waves that can be used to describe the dynamic properties of rocks. Physical properties of carbonate rocks such as water content, density, hardness, permeability, porosity, wave velocity and abrasivity can be assessed and estimated using P-wave velocity. One of the important characteristics in rock is its ability to remain stable. In this research, seismic refraction survey was applied to measure the strength of carbonate rocks for tunnel stability design. The findings revealed that the regression between the primary velocity and the uniaxial compressive strength R2 was 0.8592, indicating that the rock was firm and solid. Observation by physical visual test showed that the rock samples with yellowish-grey and light grey colours were categorized in the weathering grade II and III, respectively. The results have concluded that the rocks in the proposed area met the full requirements for tunnelling construction.

scholarly journals Shallow geophysical techniques to investigate the groundwater table at the Great Pyramids of Giza, Egypt

2019 ◽  
Vol 8 (1) ◽  
pp. 29-43 ◽  
Author(s):  
Sharafeldin M. Sharafeldin ◽  
Khalid S. Essa ◽  
Mohamed A. S. Youssef ◽  
Hakan Karsli ◽  
Zein E. Diab ◽  
...  
Keyword(s):  
Water Table ◽  
Seismic Velocity ◽  
Seismic Refraction ◽  
Groundwater Table ◽  
Near Surface ◽  
Groundwater Aquifer ◽  
Geophysical Surveys ◽  
Subsurface Layers ◽  
Average Water ◽  
Ground Penetrating

Abstract. The near-surface groundwater aquifer that threatened the Great Pyramids of Giza, Egypt, was investigated using integrated geophysical surveys. A total of 10 electrical resistivity imaging, 26 shallow seismic refraction, and 19 ground-penetrating radar surveys were conducted in the Giza Plateau. Collected data for each method were evaluated by state-of-the art processing and modeling techniques. A three-layer model depicts the subsurface layers and better delineates the groundwater aquifer and water table elevation. The resistivity of the aquifer layer and seismic velocity vary between 40 and 80 Ωm and between 1500 and 2500 m s−1, respectively. The average water table elevation is about +15 m, which is safe for the Great Sphinx, but it is still subjected to potential hazards from the Nazlet El-Samman suburb where the water table elevation reaches 17 m. A shallower water table at the Valley Temple and the tomb of Queen Khentkawes, with a low topographic relief, represents severe hazards. It can be concluded that a perched groundwater table is detected in the elevated topography to the west and southwest that might be due to runoff and capillary seepage.

Joint inversion of seismic refraction and resistivity data using layered models — Applications to groundwater investigation

Geophysics ◽  
2015 ◽  
Vol 80 (1) ◽  
pp. EN43-EN55 ◽  
Author(s):  
Niklas Juhojuntti ◽  
Jochen Kamm
Keyword(s):  
Case Studies ◽  
Joint Inversion ◽  
Seismic Refraction ◽  
Sedimentary Basins ◽  
Groundwater Exploration ◽  
In Situ Tests ◽  
Seismic Reflection Data ◽  
Near Surface ◽  
Resistivity Data ◽  
Geotechnical Investigations

We developed a method for joint inversion of seismic refraction and resistivity data, using sharp-boundary models with few layers (typically three). We demonstrated the usefulness of the approach via examples from near-surface case studies involving shallow groundwater exploration and geotechnical investigations, although it should also be applicable to other types of layered environments, e.g., sedimentary basins. In our model parameterization, the layer boundaries were common for the resistivity and velocity distributions. Within the layers, only lateral variations in the material parameters (resistivity and velocity) were allowed, and we assumed no correlation between these. The inversion was performed using a nonlinear least-squares algorithm, using lateral smoothing to the layer boundaries and to the materialparameters. Depending on the subsurface conditions, the smoothing can be applied either to the depth of the layer boundaries or to the layer thicknesses. The forward responses and Jacobian for refraction seismics were calculated through ray tracing. The resistivity computations were performed with finite differences and a cell-to-layer transform for the Fréchet derivatives. Our method performed well in synthetic tests, and in the case studies, the layer boundaries were in good agreement with in situ tests and seismic reflection data, although minimum-structure inversion generally has a better data fit due to more freedom to introduce model heterogeneity. We further found that our joint inversion approach can provide more accurate thickness estimates for seismic hidden layers.

Integration of Multi-geophysical Approaches to Identify Potential Pathways of Heavy Metals Contamination - A Case Study in Zeida, Morocco

2020 ◽  
Vol 25 (3) ◽  
pp. 415-423
Author(s):  
Ahmed Lachhab ◽  
El Mehdi Benyassine ◽  
Mohamed Rouai ◽  
Abdelilah Dekayir ◽  
Jean C. Parisot ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Seismic Velocity ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Electrical Current ◽  
P Wave ◽  
Low Resistivity ◽  
Refraction Tomography ◽  
Geophysical Surveys

The tailings of Zeida's abandoned mine are found near the city of Midelt, in the middle of the high Moulouya watershed between the Middle and the High Atlas of Morocco. The tailings occupy an area of about 100 ha and are stored either in large mining pit lakes with clay-marl substratum or directly on a heavily fractured granite bedrock. The high contents of lead and arsenic in these tailings have transformed them into sources of pollution that disperse by wind, runoff, and seepage to the aquifer through faults and fractures. In this work, the main goal is to identify the pathways of contaminated water with heavy metals and arsenic to the local aquifers, water ponds, and Moulouya River. For this reason, geophysical surveys including electrical resistivity tomography (ERT), seismic refraction tomography (SRT) and very low-frequency electromagnetic (VLF-EM) methods were carried out over the tailings, and directly on the substratum outside the tailings. The result obtained from combining these methods has shown that pollutants were funneled through fractures, faults, and subsurface paleochannels and contaminated the hydrological system connecting groundwater, ponds, and the river. The ERT profiles have successfully shown the location of fractures, some of which extend throughout the upper formation to depths reaching the granite. The ERT was not successful in identifying fractures directly beneath the tailings due to their low resistivity which inhibits electrical current from propagating deeper. The seismic refraction surveys have provided valuable details on the local geology, and clearly identified the thickness of the tailings and explicitly marked the boundary between the Triassic formation and the granite. It also aided in the identification of paleochannels. The tailings materials were easily identified by both their low resistivity and low P-wave velocity values. Also, both resistivity and seismic velocity values rapidly increased beneath the tailings due to the compaction of the material and lack of moisture and have proven to be effective in identifying the upper limit of the granite. Faults were found to lie along the bottom of paleochannels, which suggest that the locations of these channels were caused by these same faults. The VLF-EM surveys have shown tilt angle anomalies over fractured areas which were also evinced by low resistivity area in ERT profiles. Finally, this study showed that the three geophysical methods were complementary and in good agreement in revealing the pathways of contamination from the tailings to the local aquifer, nearby ponds and Moulouya River.

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