Applying the Seismic Refraction Tomography for Site Characterization

Azwin, I. N.; Saad, Rosli; Nordiana, M. M.

doi:10.1016/j.apcbee.2013.05.039

Cited by 41 publications

(20 citation statements)

References 4 publications

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“…The shallow seismic refraction method is ideal for estimating, with reasonable accuracy, the depth of different geological interfaces for different purposes such as geotechnical [49] and engineering geological investigations [50], site characterization of landslide areas [51] hydrogeological analysis [52] (Prekopová et al, 2016) archaeological exploration [53,54] and site characterizations of karst areas for large penetration and at high spatial resolution [3,20,55]. Further details about the application of the method can be found in [56].…”

Section: Seismic Refraction Survey (Srs)mentioning

confidence: 99%

Detection of Cover Collapse Doline and Other Epikarst Features by Multiple Geophysical Techniques, Case Study of Tarimba Cave, Brazil

Hussain

Uagoda

Borges

et al. 2020

Water

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Reliable characterization of the karst system is essential for risk assessment where many associated hazards (e.g., cover-collapse dolines and groundwater pollution) can affect natural and built environments, threatening public safety. The use of multiple geophysical approaches may offer an improved way to investigate such cover-collapse sinkholes and aid in geohazard risk assessments. In this paper, covered karst, which has two types of shallow caves (vadose and fluvial) located in Tarimba (Goias, Brazil), was investigated using various geophysical methods to evaluate their efficiency in the delineation of the geometry of sediments filled sinkhole. The methods used for the investigation were Electrical Resistivity Tomography (ERT), Seismic Refraction Survey (SRS), Seismic Refraction Tomography (SRT) and the Very Low Frequency Electromagnetic (VLF-EM) method. The study developed several (2D) sections of the measured physical properties, including P-wave velocity and electrical resistivity, as well as the induced current (because of local bodies). For the analysis and processing of the data obtained from these methods, the following approaches were adopted: ERT inversion using a least-square scheme, Karous-Hjelt filter for VLF-EM data and time-distance curves and Vp cross-sections for the SRS. The refraction data analysis showed three-layered stratigraphy topsoil, claystone and carbonate bedrock, respectively. The findings obtained from ERT (three-layered stratigraphy and sediment-filled doline), as well as VLF-EM (fractured or filled caves as a positive anomaly), were found to be consistent with the actual field conditions. However, the SRS and SRT methods did not show the collapsed material and reached the limited the depth because of shorter profile lengths. The study provides a reasonable basis for the development of an integrated geophysical approach for site characterization of karst systems, particularly the perched tank and collapse doline.

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Section: Seismic Refraction Survey (Srs)mentioning

confidence: 99%

Detection of Cover Collapse Doline and Other Epikarst Features by Multiple Geophysical Techniques, Case Study of Tarimba Cave, Brazil

Hussain

Uagoda

Borges

et al. 2020

Water

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“…It can also be applied on a variety of spatial scales, from ranges of hundreds of metres, down to engineering or archaeological investigations of single columns in ancient buildings, as well as resolving velocity gradients, lateral velocity changes within the subsurface with greater ability and for modelling localised velocity anomalies (Cardarelli and de Nardis, 2001). In addition, SRT may be applied in geologic settings where conventional refraction method fails, such as areas of compaction, karst, and zone faults, as well as in areas with extreme topography or complex near-surface structures where the user has little or no prior knowledge of subsurface structures (Dutta, 1984;Zhang and Toksoz, 1998;Azwin et al, 2013), and in areas with serious limitations in spread length.…”

Section: Seismic Refraction Tomographymentioning

confidence: 99%

“…The Mining-Geology-Petroleum Engineering Bulletin and the authors ©, 2019, pp. 93-111, DOI: 10.17794/rgn.2019.1.9 shotpoints and complex mathematic algorithms to fi t a more fl exible model to produce a high resolution subsurface profi le (Azwin et al, 2013;Bery, 2013).…”

Section: Introductionmentioning

confidence: 99%

Insight Into Seismic Refraction and Electrical Resistivity Tomography Techniques in Subsurface Investigations

Akingboye

Ogunyele

2019

MGPB

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Geophysical subsurface investigations use the principles of physics to unravel intrinsic Earth's subsurface features and nature of the underlying geology. Over the past two decades, the use of Seismic Refraction Tomography (SRT) and Electrical Resistivity Tomography (ERT) for subsurface investigations has greatly improved the quality of acquired data for two-and three-dimensional (2D and 3D) surveys. SRT employs more shotpoints and receivers than the conventional seismic refraction for its imaging technique. ERT uses automated multi-electrode array systems to improve the confidence of large and dense data collection. SRT and ERT techniques use powerful inversion algorithms to achieve high resolution subsurface inversion models for resolving subsurface characteristics and geological conditions over a complex and larger area that may be diffi cult with the use of their conventional methods. The 2D and 3D inversion models (tomograms) generated from the fi eld data sets of these techniques effi ciently ameliorate inaccurate subsurface boundaries and structural delineation with higher depth resolution, especially the 3D inversion models for areas of complex geology. These state-of-the-art techniques have extensively been used for groundwater, environmental, engineering and mining investigations among others. This study provides insight from theories to data inversion techniques for the known tomography techniques (SRT and ERT) in use for subsurface investigations.

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“…In practice, many shots are taken before the first receiver group, at each receiver location and beyond the far receiver group. Through gridded inversion of the first arrival travel times of refracted seismic energy recorded at the stations, the method is able to interpret velocity changes in the subsurface as gradient with respect to depth of the subsurface along the profile but not necessarily in relation to the medium or refractor with high velocity contrast [7,8,9]. The method is therefore suitable for delineating both vertical and lateral variations in near surface characteristics.…”

Section: Introductionmentioning

confidence: 99%

Near Surface Characterization of Ebem Community, Ohafia Abia State, Using Seismic Refraction Tomography

Nwankwo¹,

Ogagarue²

2019

JGG

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Seismic refraction tomography was carried out in Ebem community, Ohafia, eastern Nigeria, which recently experienced erosional landslide. The aim was to determine the near surface characteristics in the area, offer possible geologic explanation to the frequent landslides which occur in the area and provide information on potential slide zones to mitigate future disasters. A total of three seismic refraction profiles were carried out using a 12-channel ABEM Terrace MK III digital seismograph with inter-channel spacing of 10 m. Shots were generated by means of a 6 kg sledge hammer and metal plates at 23.5 m before the first and after the last geophone group respectively, and at every geophone station, giving a total length of 157 m for each profile. Velocity structure from the study shows that the area is made up of three different layers on account of velocity distribution, which includes a top layer of unconsolidated, low velocity dry sands assumed to be weathering layer with velocity ranging from about 412 m/s to 1,300 m/s. This layer varies in thickness from about 9 m at the flanks to about 35 m at the center, creating a thick zone of low velocity at the center. This is underlain by a very thin, apparently more compacted sub-weathering layer containing a mixture of sands and clay in which velocity and thickness vary from about 1,300 m/s to 3,000 m/s, and 2,31 m to 3.01 m respectively. Compressional velocity in the area varies from about 412 m/s to about 4.090 m/s, and velocities in the bedrock generally exceed 3,000 m/s; the velocity generally increasing with depth from the surface. The results suggest that the frequent landslides in the area are likely the result of the thick, unconsolidated and permeable dry sands underneath the surface which presumably acts as a sinkhole for surface water runoffs orchestrated by the frequent rainfall which is common in the area. Areas with the highest thickness of weathering are the most vulnerable to sliding in the area.

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Applying the Seismic Refraction Tomography for Site Characterization

Cited by 41 publications

References 4 publications

Detection of Cover Collapse Doline and Other Epikarst Features by Multiple Geophysical Techniques, Case Study of Tarimba Cave, Brazil

Detection of Cover Collapse Doline and Other Epikarst Features by Multiple Geophysical Techniques, Case Study of Tarimba Cave, Brazil

Insight Into Seismic Refraction and Electrical Resistivity Tomography Techniques in Subsurface Investigations

Near Surface Characterization of Ebem Community, Ohafia Abia State, Using Seismic Refraction Tomography

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