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Using non-destructive test to validate and calibrate smart sensors for urban pavement monitoring
Published in Inge Hoff, Helge Mork, Rabbira Saba, Eleventh International Conference on the Bearing Capacity of Roads, Railways and Airfields, Volume 1, 2021
A. Di Graziano, S. Cafiso, A. Severino, F. Praticò, R. Fedele, G. Pellicano
The ground penetrating radar is a geophysical radar system with two antennas and receivers used to perform non-destructive investigations of underground characteristics with high resolution and in depth (up to 3.2 m from the surface).
Ground water monitoring and site remediation
Published in Neal Wilson, Soil Water and Ground Water Sampling, 2020
Geophysical methods may be employed either to evaluate natural hydrogeologic conditions such as depth to water table, aquifer extent, or depth to bedrock surface or to locate buried wastes, drums, or tanks.2 Geophysical methods include airborne, surface, or downhole geophysics. Soil gas surveys may provide information about the aerial extent of contamination at a site. Indirect methods of obtaining geologic information, such as geophysical methods and soil gas surveys, may be used to augment the evidence gathered from direct field methods but should not be used as a substitute for them.8 Data derived from monitoring points may provide information about the extent of contamination but generally not about the original mass of contaminants (Barcelona, M.J., personal communication).
Assessment of Permeability
Published in Pat M. Cashman, Martin Preene, Groundwater Lowering in Construction, 2020
Surface geophysics was introduced in Section 11.7.4.1. Surface geophysical methods include seismic refraction methods, gravity surveying, electromagnetic surveying and resistivity soundings (Barker, 1986). These methods measure the variation in specific physical properties of the sub-surface environment and apply theoretical and empirical correlations to infer the structure of the ground and groundwater regime. Typical applications include mapping the extent of gravel deposits within extensive clay strata or locating buried channel features within drift deposits overlying bedrock (Macdonald et al., 1999).
Tracking surface and subsurface deformation associated with groundwater dynamics following the 2019 Mirpur earthquake
Published in Geomatics, Natural Hazards and Risk, 2023
Muhammad Younis Khan, Ekrem Saralioglu, Syed Ali Turab, Sher Muhammad
Like other non-destructive near surface geophysical methods (e.g. ERT), the ground penetrating radar (GPR) method has been applied to shallow subsurface investigations due to its high-resolution, time and cost-effective nature (Lapenna et al. 2003; Khan et al. 2019, 2020, 2021c). Recently, GPR has gained popularity in studies related to the detection of faults and fracture networks (Schwarz and Krawczyk 2020), slope instabilities (Khan et al. 2021c), and landslides (Hu and Shan 2016). The geophysical methods, for instance, GPR is one of the reliably accurate mapping tools to study a single site and/or imaging of a localized subsurface deformation but difficult to perform such surveys over an extensive earthquake/Karst depressions/landslide affected area to detect the near-surface target features. Among the aforementioned geohazards, few studies focusing on coseismic liquefaction and related ground failure have been conducted using field GPR measurements (Liu and Li 2001; Baradello and Accaino 2016).
Gravity-magnetic cross-gradient joint inversion by the cyclic gradient method
Published in Optimization Methods and Software, 2020
Gravimetric and magnetic explorations are two important methods in geophysical prospecting [13,23,31]. Both methods are volume explorations and can be performed quickly and economically. The gravimetric prospecting is the measurement of gravimetric anomalies which are caused by geological bodies. These anomalies are completely different from those caused by the surrounding rocks, which are used to determine the spatial location, size and shape of these geological bodies. As long as the buried geological body has a certain residual mass, the burial depth is small and the topographic fluctuation has little influence, gravity anomalies can be measured by gravimetric survey [19]. Similarly, magnetic prospecting is a geophysical method to study the distribution of geological structure, mineral resources or other prospecting objects through observations and analysis of magnetic anomalies caused by magnetic differences among rocks, ores or other prospecting objects. Magnetic exploration studies magnetic anomalies, which are mainly caused by the magnetization of magnetic rocks (ores) in the magnetic field of the earth. The main task of magnetic exploration is to determine different parameters according to the measured magnetic anomaly [19]. The parameters include the geometric parameters (position, shape, size, occurrence) and magnetic parameters (magnitude and direction of magnetization) of the magnetic body which causes the magnetic anomaly [30].
Interpreting geology from geophysics in poly-deformed and mineralised terranes; the Otago Schist and the Hyde-Macraes Shear Zone
Published in New Zealand Journal of Geology and Geophysics, 2019
Casey C. Blundell, Robin Armit, Laurent Ailleres, Steven Micklethwaite, Adam Martin, Peter Betts
Because the geophysical signals are the cumulative response from a 3D volume of crust (Blaikie et al. 2017), the data can also provide 3D information about geological terranes including the dip and plunge of geological features (via assessment of gradients in the data). It is also possible to determine small- and large-scale geometric relationships, including overprinting relationships, structural juxtaposition and kinematics (Valenta et al. 1992; Betts et al. 2003). Available surface geology and petrophysical data (e.g. magnetic susceptibility, specific gravity etc.) are important for furnishing further constraints to geophysical interpretations (Valenta et al. 1992; Hoover et al. 1995; Betts et al. 2003). Advances in data collection and processing methods, as well as computing power, have greatly improved our ability to effectively interpret high resolution (<500 m line spacing) data. However, whilst geophysical data are increasingly useful tools for resolving geologic problems, unique interpretation of deformed and/or metamorphosed terranes is rarely possible. Lacking geological constraint, several non-unique solutions to responses observed in geophysical data are possible. Geophysical methods have limited use where surveys are poorly designed, or the chosen methods are unsuitable for the surveyed geological terrane.