CRSP, numerical results for an electrical resistivity array to detect underground cavities

Abstract

This paper is devoted to the application of the Combined Resistivity Sounding and Profiling electrode configuration (CRSP) to detect underground cavities. Electrical resistivity surveying is among the most favorite geophysical methods due to its nondestructive and economical properties in a wide range of geosciences. Several types of the electrode arrays are applied to detect different certain objectives. In one hand, the electrode array plays an important role in determination of output resolution and depth of investigations in all resistivity surveys. On the other hand, they have their own merits and demerits in terms of depth of investigations, signal strength, and sensitivity to resistivity variations. In this article several synthetic models, simulating different conditions of cavity occurrence, were used to examine the responses of some conventional electrode arrays and also CRSP array. The results showed that CRSP electrode configuration can detect the desired objectives with a higher resolution rather than some other types of arrays. Also a field case study was discussed in which electrical resistivity approach was conducted in Abshenasan expressway (Tehran, Iran) U-turn bridge site for detecting potential cavities and/or filling loose materials. The results led to detect an aqueduct tunnel passing beneath the study area.

Uncertainty of the 2D Resistivity Survey on the Subsurface Cavities

“…In line with our results, the field study and numerical modeling have shown that the DD array can accurately resolve the subsurface structures such as cavity [38,67], thin dike [25], buried wall [29,32], and sinkhole [21]. These structures were moderately recovered by the WS and PD arrays [24,26,69]. The pole-pole array is generally the poorest in terms of model accuracy and image quality [25,32], consistent with our study.…”

“…Compared to the numerical results, the experimental cavity anomaly in all the tested arrays showed considerable underestimation of anomaly depth. The depth underestimation in cavity studies can lead to inappropriate interpretation, similar to other field studies [26,68]. Since our study was conducted in shallow sandy clay, the patchily distributed high and low resistive features were inferred as the inversion artefacts.…”

“…However, the PD array provides asymmetrical resistivity data that adds bias to the inverted models [21,25], whereas the Wenner-Schlumberger (WS) configuration is moderately sensitive to both lateral and vertical variations. The WS array also has a higher signal-to-noise ratio, yet it recovers a relatively lower resistivity contrast compared to the DD arrays [26,27]. On the other hand, the pole-pole (PP) array can produce comprehensive horizontal data coverage and survey greater depths as compared to other types of arrays.…”

Detection of urban underground cavities using seismic scattered waves: a case study along the Xuzhou Metro Line 1 in China

“…Engineering geophysics provides solutions to a wide range of environmental and engineering problems associated with construction (Sharma, 1997; Lei et al ., 2006; Yalcinkaya et al ., 2016). A variety of engineering geophysical methods have been used to detect underground cavities, including resistivity (Kemna et al ., 2002; Fasani et al ., 2013; Zhang et al ., 2014; Amini and Ramazi, 2017), transient electromagnetic methods (Zhang et al ., 2011), ground‐penetrating radar (GPR) (Booth et al ., 2011; Anchuela et al ., 2014) and shallow seismic methods (Grandjean et al ., 2002). However, the volumetric effects of electrical prospecting methods, environmental limitations of GPR and the high cost of cross‐hole geophysics often make these approaches insufficient for meeting the high‐resolution and low‐cost exploration needs of urban underground cavities.…”

Detected of Gypsum Soil Layer by Using 2d and 3d Electrical Resistivity Imaging Techniques in University of Anbar, Iraq

“…Resistivity methods, especially 2D and 3D electrical resistivity imaging (ERI) techniques are very useful in this situation. Application of these techniques for geotechnical site characterization is very useful to determine the subsurface geology and the subsurface structures such as cavities, voids, soil stability (Auken et al, 2006: Sudha et al, 2009Wisén et al, 2012;Mohammad, 2012;Loke et al, 2013;Thabit and Abed, 2014;Abdelwahab, 2013;Hassan and Nsaif, 2016;Amini and Ramazi, 2017;Hassan et al, 2018 andAziz et al, 2019).…”