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1

A parallel improved PSO algorithm with genetic operators for 2D inversion of resistivity data

Abril Jorge L., Vasconcelos Marcos A., Barboza Francisco M., Mojica Oscar F.

Acta Geophysica

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2022

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Vol. 70, no 3

1137--1154

EN

In this paper, an improved particle swarm optimization technique known as elitist-mutated particle swarm optimization (EMPSO) was applied in the 2D electrical resistivity imaging, a complex and highly nonlinear optimization problem. The EMPSO enables better exploration of the search space, by replacing particles with a worse performance by the best particle of the swarm mutated in random positions. Nevertheless, this technique, as any other based on a population of models, costs much computation time in solving optimization problems with a large number of unknown parameters. We addressed this problem by developing a parallel version of the EMPSO that supports pure MPI and hybrid MPI-OpenMP modes, and we named as parallel elitist-mutated PSO (PEMPSO). The solution to the inverse problem is based on minimizing an objective function with a regularization term to create a mathematically stable solution. Total variation and global smoothness regularizations were used in the inversion of synthetic data obtained from simple models and a set of real data of a highly complex geological/geotechnical nature. By virtue of the features of the synthetic models and the geology of the local where the data were acquired, the inversions with total variation regularization provided the best outcomes. Additionally, we have improved the execution time significantly with our parallel solution (the pure MPI model turned out to be better than the hybrid model) in comparison with the sequential version. Cumulative frequency distribution of errors between modeled and observed apparent resistivity data for all experiments was used to validate the PEMPSO technique for estimating resistivity.

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Geofizyczne rozpoznanie zasięgu kry jurajskiej w Gołaszynie k. Łukowa

Mendecki M., Świder M., Nowaczyńska I., Mamak A., Odrobińska J., Piotrowska P., Rewers J., Tymińska A.

Przegląd Geologiczny

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2018

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Vol. 66, nr 1

48--54

EN

The paper deals with the study of the Middle Jurassic clays near the town of Łuków, to identify its position, depth and thickness defined using geoelectrical techniques. The electrical properties of the ground were determined by a non-invasive 2D Resistivity Imaging Method which involves the investigation of the distribution of resistivity in the ground in X and Z direction. The measurements were carried out on four survey profiles that allowed to distinguish the horizontal and vertical extent of the Jurassic raft. It is not regular, but represents a more complicated structure. The values of resistivity, identified with the Jurassic clays, were very low and reached about 1-20 Q,m, which allowed interpreting, on each resistivity cross-section, its thickness changing from a few metres up to tens of metres.

3

Zastosowanie metody obrazowania elektrooporowego do rozpoznania podłoża Południowej Obwodnicy Warszawy

Kowalczyk S., Cabalski K., Radzikowski M., Jędrzejewski J.

Przegląd Geologiczny

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2017

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Vol. 65, nr 10/2

772--778

EN

The article presents the usage of electrical resistivity imaging (ERI) in ground recognition for linear constructions such as the Warsaw Southern Ring-Road. Measurements were performed in a gradient array, on five segments of the route, with previously researched geological conditions. Measurement method intended to probe the soil matrix on different depths. Therefore, the electrode array was set to 2 to 5 meters. The resulting image of resistivity differed in resolution. Resistivity images were correlated with geological data from boreholes in geology-engineering documentation and other widely available geological information from databases and literature. This allowed to limit ambiguity of interpretation of two-dimensional model of near surface soil matrix resistivity. Thereby, individual ranges of resistivity were assigned to geological content. The measurements allowed to identify geological horizontal variability. Electrical resistivity imaging research confirmed its utility in the recognition of spatial distribution of geological media in foundation soil. The analysis of completed surveys allowed to designate the following areas: locations where anthropogenic and organic soils occur, probable location of the edge of the upland on the eastern side of Vistula River and upper relief of local Neogene clays.

4

Zastosowanie metody elektrooporowej do rozpoznania złóż surowców skalnych

Frycz M., Jeleń M.

Kruszywa : produkcja - transport - zastosowanie

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2017

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Nr 2

86--93

PL

Metody geofizyczne, ze szczególnym uwzględnieniem tomografii elektrooporowej, w ostatnich latach zyskują coraz większe znaczenie. Jest to efektem ciągłego postępu technologicznego, jaki dokonuje się w dziedzinie aparatur pomiarowych. Artykuł został poświęcony wykorzystaniu metody elektrooporowej w badaniu złóż – zarówno w fazie ich eksploatacji, jak i poszukiwań.

EN

Geophysical methods, with special regard to electrical resistivity imaging, have gained increasing significance in recent years. It is the result of continuous improvement in the field of measuring equipment. The article addresses electrical resistivity method application in deposit exploration, both at the stage of their location and mining. The employment of modern and advanced equipment enables to effectively determine deposit borders and depth. It also gives information about the physical properties of rock. The results may be used as drilling complementary information or autonomous source of geological data. The examples of electrical resistivity imaging application presented in the paper relate to data collected in order to determine the profitability of plot purchase before the exploitation process or deposit ceiling depth and weathering zones in existing mines. The aim of the measurements was to gain geological information on various rock types – basalts, limestones, dolomites and sand-gravel sediments.

5

Application of electrical resistivity imaging and land surveying in the analysis of underground construction impact on the Warsaw Scarp

Kaczmarek Ł., Mieszkowski R., Woźniak M., Dybciak T.

Studia Quaternaria

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2016

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Vol. 33, Nr 2

83--90

EN

The paper presents the analysis of the II Underground Line construction’s impact on the Warsaw Scarp with the use of the electrical resistivity imaging (ERI, also known as the electrical resistivity tomography) and further total station position measurements. The underground passes under the scarp perpendicular in the area of Dynasy Street 6, in Downtown district. The electrical resistivity imaging was performed for recognition of the geological structure and a potential landslide surface or zone. The gradient system was used during the prospection. In these analyses, the longitudinal section was 40 m long, and the depth of survey amounted to 6 m. In the case of the 200 m long transverse section, the resulted depth of survey was 30 m. The geophysical image of the longitudinal section, does not contain loosening soil zones, which could indicate slip surface. Next, total station measurements, which were tied to the archival geodetic observations’ results, were carried out. The aim of the measurements was to verify the activity of the horizontal and vertical displacements. The TBM excavation process led to summary vertical displacements up to approx. 24 mm and horizontal displacements amounting to approx. 13 mm. To sum up, the current land surveys reveals minor underground line’s construction impact on the scarp displacement. Nevertheless, the sensitive urban environment requires further monitoring, especially that the operation loads can result in displacement rate change.

6

Application of Electrical Resistivity Imaging for Engineering Site Investigation. A Case Study on Prospective Hospital Site, Varamin, Iran

Amini A., Ramazi H.

Acta Geophysica

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2016

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Vol. 64, no. 6

2200--2213

EN

The article addresses the application of electrical resistivity imaging for engineering site investigation in Pishva Hospital, Varamin, Iran. Some aqueduct shafts exist in the study area backfilled by loose materials. The goals of this study are to detect probable aqueduct tunnels and their depth, investigate filling quality in the shafts as well as connection(s) between them. Therefore, three profiles were surveyed by dipoledipole electrode array. Also, to investigate the potentially anomalous areas more accurately, five additional resistivity profiles were measured by a Combined Resistivity Sounding-Profiling array (CRSP). According to the results of 2-D inversion modelling, a main aqueduct tunnel was detected beneath the central part of the site. Finally, the resistivity pattern of the detected aqueduct system passing the investigated area was provided using the obtained results.