The ct method uses data from multiple csl logs at different sourcereceiver height offsets. Many tomographic interpretations of crosshole seismic traveltimes have approximated the raypaths with straight lines connecting the source and receiver. Lowell 1 university avenue, lowell, massachusetts, 01854, usa les r. Seismospect is a simple and efficient platform used for the creation of a personalized library of ground motion records, allowing the user to save them all in a single file making it easy to handle an. Examination of a new crosshole sonic logging system for. Borehole seismic methods largely fall into two categories, namely, crosshole seismics and seismic tomography. This method provides little indication of concrete soundness outside the cage. The geotechnical engineering circular number 10 of the usa federal highway administration states that tomography provides enhanced evaluation of potential defects and is among techniques that, while requiring specialized expertise for data interpretation, may be warranted for large structures. Sy8 cross hole sonic logging analyzer software can display the threedimensional tubular slice diagram, that is, the variation of the speed value of the external profile of the pile tested is displayed by using the chromatogram, and then the chromatogram is crimped and connected to form the tubular slice diagram to show the variation trend of the speed value of the pile.
Crosshole seismic tomography geophysics geoscienceworld. Interwell seismic tomography for solving engineering geological problems. Cross hole sonic logging foundation test group consulting. Crosshole seismic tomography geophysics seg library. Crosshole seismic tomography which involves measuring travel times of seismic ray paths between two or more boreholes in order to derive an image of seismic velocities between the wells offers an. Seismic tomography, crosshole, downhole geotomographie gmbh. First, the crosshole seismic tomography method eliminates.
Crosshole sonic logging and velocity tomography imaging of. The most popular in engineering geophysics was crosshole seismotomography. Crosshole seismic tomography which involves measuring travel times. For boulder detection in civil engineering, crosshole tomography method can only provide 2d velocity structure model between the two wells, however. The use of crosshole tomography to evaluate drilled shaft repairs les r. View our crosshole downhole seismic testing equipment to learn more. Crosshole sonic logging csl is a method to verify the structural integrity of drilled shafts and other concrete piles the csl method is considered to be more accurate than sonic echo testing in the determination of structural soundness of concrete within the drilled shaft inside of the rebar cage. Pdf seismic crosshole tomography has been commonly used in oil and gas exploration and the mining. Application of crosshole tomography for assessment of. We use the windowsbased tomo1 software and slicerdicer software for users of an olson instruments crosshole sonic logging system. Laboratory study of the crosshole resistivity tomography. In chum cross hole ultrasonic monitor, the operator may choose fat based tomography, attenuation based tomography, or a combination. Home olson instruments ndt equipment ultrasonic testing.
As for in hole and boreholetosurface surveys, additional surveys can be performed along multiple orientations at the single borehole site to generate more survey insights. Figure 1a is a sample shot gather on which the first arrivals of the far offset traces cannot be clearly identified and thus the picked times are not reliable at all. Crosshole sonic logging csl is the most accurate and reliable technique for assessing the integrity of deep foundation elements constructed onsite from concrete or grout. Application of crosshole tomography for assessment of soil. The geophysical tomography team crosshole resistivity.
Ultrasonic cross hole testing of deep foundations 3d imaging. New tomography software for cross hole sonic logging pditomo create a free account and view content that fits your specific interests in geotechnical engineering learn more register. The program replaces an older tomography program, with significant advantages. Digisens 3d tomography software solutions for industry and. Pdf the potential of seismic crosshole tomography for. Tomography software analyses provide 2d and 3d display of internal concrete conditions, including animation of defects. Application engineer technician computed tomography gom is a leading innovator in the development of optical 3d metrology systems and measurement software, with a workforce currently numbering around 500. X86 version of diinso is totally free and can be use in scientific purposes, but it also has not any guarantees, so use diinso at your own risk.
It is shown that while the geological sections do not contain velocity information they have provided. Electrical resistivity tomography ert is a popular geophysical subsurfaceimaging technique and widely applied to mineral prospecting, hydrological exploration, environmental investigation and civil engineering, as well as archaeological mapping. However, crosshole geophysical testing may show that the ground has been suitably improved in some cases where cone penetration tests are unable to demonstrate an equivalent level of improvement. Cross borehole tomography is a common method for exploring complex or deep terrain. The fourth chapter is an attempt to apply staggered grid inversion in a seismic crosshole tomography to increase its resolution. Crosshole sonic logging evaluates the integrity of the concrete of drilled shafts and other bored or castinplace deep foundations. Execution and basic principles the cross hole test on piles is intended to verify the quality of the concrete along the shaft e. Cross hole seismic tomography which involves measuring travel times of seismic ray paths between two or more boreholes in order to derive an image of seismic velocities between the wells offers an. Pr actical implications of gpr investigation using 3d data. Tomographic velocity images are powerful analysis tools used to characterize the size, shape, extent, and severity of potential defects and anomalies. For our customers, we conduct seismic field surveys and the. A powerful pattern filtering software has been developed by delphi tool, and batch signals can be more efficiently processed. Using ct software, once the component is scanned, the collected data is. Grl operates the largest dynamic pile testing firm in the world, as well as an industry leading provider of integrity test methods for deep foundations including thermal integrity profiling, crosshole sonic logging, and low strain integrity testing.
We accompany manufacturers in designing and dimensioning 3d systems and software solutions. Learn more about olsons ultrasonic testing and ndt equipment. Many more articles using imaging and tomography are being published currently compared to 20 years ago. Computed tomography used in reverse engineering saves time and enables easy manipulation of data for analyzing and testing a wide range of components. Geotomographie, founded in 1999 in germany, provides complete solutions for borehole and nearsurface seismic surveys to geophysical, engineering and mining companies. The results of crosshole seismic tomography at sites where there is good geological control are presented. Reflexw software, according to selected module, covers complete range of wave data seismic, gpr,ultrasound and their processing throgh different geometry assemblings such as refraction seismic, reflection seismic, surface investigations and borehole crosshole, tomography and combination of borehole and surface measurements. Our software reflexw is one of the worlds most popular geophysical near surface. We design seismic borehole sources and receivers and develop specifically tailored software. Qualitative and quantitative analysis of certain electrode arrays. Multihole seismic modeling in 3d space and crosshole seismic tomography analysis for boulder detection. Borehole logging and crosshole seismic tomography investigation of unconsolidated soil materials in sikeston, mo, helped in defining the engineering properties of the investigated earth material interposed between two boreholes for a depth of 39 m below the surface. Terracon foundation and structural consulting professionals offer ndt testing of deep foundations using cross hole sonic logging csl, cross hole tomography ct and sonic echoimpulse response seir methods.
Model stacking technique to improve the quality of resistivity models. Rsmsy8 ultra sonic pile integrity ct imaging tester. Seismic methods can provide detailed information about rock properties and geological structure between boreholes. Advances in tomography and imaging is a unique assemblage of contributions exploring applications of imaging and tomography. When combined with an swave survey, the data can additionally be used to provide information on material stiffness properties see crosshole seismic surveys. Bureau of mines recently completed a cooperative study with the u. Crosshole seismic tomography and borehole logging for engineering site characterization in sikeston, mo, usa angioni, tiziana. Home our research engineering geology geophysical tomography crosshole resistivity tomography crt crosshole resistivity tomography crt figure 1. Examination of a new crosshole sonic logging system for integrity testing of drilled shafts samuel g. Comparisons have been made between the tomograms and the geological cross sections in order to assess the technique under in situ conditions.
Sound skills in dealing with application software in an industrial environment e. Crosshole seismic tomography crosshole seismic tomography cst method allows to obtain a detailed distribution of pressure p and shear s wave velocities in the crosswell space over the entire depth of study. This website beta version contains information on geophysical methods, references to geophysical citations, and a glossary of geophysical terms related to environmental applications. Terracon foundation and structural consulting professionals offer ndt testing of deep foundations using crosshole sonic logging csl, crosshole tomography ct and sonic echoimpulse response seir methods. Tomography analysis can be performed during reprocessing when complex situations are encountered.
Ahsin farid geophysicist fugro middle east linkedin. This section contains examples for setting up and running an cross hole tomographic inversion using sippi using the reference data from arren. The primary application of borehole seismic tomography is in engineering studies for the identification of features such as fault zones and voids. In geotechnical applications, crosshole tomography is commonly used to determine the position of cracks in rocky ground and to assess the condition of deep foundation piles.
In crosshole seismic tomography, however, these datapicking errors may not be treated as random variables with a gaussian distribution and the solution may often be biased. Using this data, one can proceed to the spatial distribution of such parameters as the. The source and geophone are always at the same elevation, and the energy from each shot is measured at a single depth in each receiver hole. Already in 1917 reginald fessenden proposed a method to. Soil dynamics, geotechnical earthquake engineering. As part of continuing research aimed at the detection of subsurface tunnels and voids, the u. Application of crosshole tomography for assessment of soil stabilization by grout injection. Owing to the high cost of this test, the cone penetration test method is generally used. Mar 24, 2019 demonstration of joint inversion velocity and anisotropy parameter for 3 boreholes and surface data in zondst2d. Directinverse solver diinso is an electrical resistivity tomography ert software which orient to solve 3d direct and 2d3d inverse problems on direct current dc. Rapid advances in tomography and imaging techniques and their successful application in soil and plant science are changing our sciences today. Rayfractr geophysical software for geotechnical engineering and exploration generates subsurface velocity models from seismic first break data.
A new approach to the problem has recently been introduced by applying the principles of cross hole tomography, such that a series of sonic. A crosshole sonic logging csl and crosshole tomography ct investigation was performed at the university of massachusetts, amherst, in april of 2000, as part of a competitive program to nondestructively image known foundation defects for 6 drilled shafts. Geophysical tomography engineering geology our research. Such an approach is now used in a lot of software implementing methods of seismic tomography. Pditomo tomographic software is available for superior tomographic results providing intuitive 3d identification of questionable areas, as well as allowing for a quick and easy quantitative, comprehensive, engineering analysis. If the csl records are inconclusive or show an anomaly, the engineer may require coring or the performance of crosshole tomography to verify the shaft condition. Crosshole sonic logging and frequency tomography analysis of drilled shaft foundations to better evaluate anomalies locations. Computed tomography used in reverse engineering north star imaging blog. Ultrasonic cross hole testing of deep foundations 3d imaging yury volkovoy and richard stain sonic coring or more properly ultra sonic cross hole logging is a common test for concrete foundations and has been since the late 1960s. This direction is used for detailed studies of rocks velocity structure in the. Pdf crosshole sonic logging and frequency tomography.
Tomography is a mathematical procedure that is applied to crosshole sonic logging csl data, providing the user with a visual image of a shafts internal defects. Development of a multiscale model of electrical signature of root architectures. The grl engineer prepares a final report summarizing the csl test details, csl test results, tomography analysis if performed and recommendations. The technique involves generating electric pulses in a control and data acquisition unit. The crosshole sonic logging method is normally applied as a quality assurance qa technique for newly placed drilled shafts and auger cast piles, but can also be applied. Crossholedownhole seismic csds investigations provide information on dynamic soil and rock properties.
Crosshole seismic tomography and borehole logging for. Crosshole tomography analyses can be done to better characterize the shape of an anomaly identified in crosshol e sonic logging between a tested tube pair. Pditomo is software developed to supplement champ output from csl tests. Pdf seismic crosshole tomography has been commonly used in oil and gas exploration and the mining industry for the. More than two years experience of onshore geological environments and engineering relates geophysical projects at sites throughout the uae and qatar. New tomography software for cross hole sonic logging. Olson instruments provides the best tomographic imaging software tomo for your ndt testing needs. Supports pwave, swave and crosshole survey interpretation. Pdf application of crosshole seismic tomography in. The conventional approach involves lowering a 3component borehole geophone down one hole while lowering a source down an adjacent hole s, firing the source at some prescribed depth interval. In the case of structural civil engineering, radar tomography is quite a recent technique. Many tomographic interpretations of crosshole seismic traveltimes have approximated the raypaths with straight lines connecting the source. The seismic crosshole technique offers a means to investigate the rock mass between two or more boreholes.
Crosshole tomography ct testing and analysis is normally used in conjunction with crosshole sonic logging csl testing to provide additional information as to the size, shape, and location of a defect which has been located with standard csl testing. Fewer boreholes are needed to achieve a continuous picture of the subsurface thereby reducing overall costs and the risk of missing target features. The software analyzes wave speeds derived from arrival time data from the scans of all pairs of tubes to yield a wave speed map of the entire shaft volume. It is showed that pfm is a very effective tool in crosshole tomography signal processing, and is prospective for utilization in other realms of engineering. Investigation of a bridge foundation site in karst terrane via seismic crosshole tomography. From these measurements, parameters, such as poissons ratios and moduli, can be easily determined. Sy8 cross hole sonic logging analyzer software can display the threedimensional tubular slice diagram, that is, the variation of the speed value of the external profile of the pile tested is displayed by using the chromatogram, and then the chromatogram is crimped and connected to form the tubular slice diagram to show. Tomography software for crosshole sonic logging csl data quality assurance for deep foundations what is tomography. High resolution crosshole 2d seismic tomography youtube. Geological survey at a surface gold mine in the black hills mining district of south dakota. We set new standards in industrial metrology with our holistic solutions and are successful with them all over the globe. Experienced user of geophysical and general business software including microsoft office, adobe acrobat, autocad 2007, surf seis, geosoft oasis montaj. A variation on csl testing is crosshole tomography ct.
Works in conjunction with our freedom data pc, full training on our tomography software is provided by olson instruments. The geophysical tomography gtom team provides leadingedge technology for noninvasive geoelectrical imaging of the shallow subsurface. Application of pattern filtering method in crosshole. Deep tunnel detection using crosshole radar tomography. Seismic tomography applied to site characterization use. This software package includes crosshole survey design, model building and modeling, data preprocessing, cdp transformation, tomography, waveequation. Seismic tomography applied to site characterization. Sensitivity analysis of cross hole electrode arrays. Ct testing is often performed after the csl testing has been performed to obtain more information about the size, shape, location, and severity of a suspected defect in a shaft.
Our technology tests structures, pavements, and foundations through our concrete, asphalt, masonry, wood, soil, and rock. Computed tomography used in reverse engineering north. The crosshole seismic cs system and method determine shear and compressional wave velocity versus depth profiles. Highlights laboratory study of cross hole ert in wellknown and controlled conditions.
Crosshole sonic logging evaluates the integrity of the concrete of drilled shafts and other bored or. The software is used to image a defect in a foundation using ultrasonic velocity crosshole tomography. Pditomo pile dynamics has released the new pditomo software for analysis of crosshole sonic logging csl data. Crosshole seismic tomography cst works carried out between specified boreholes. Multihole seismic modeling in 3d space and crosshole. Crosshole downhole seismic investigations provide information on dynamic soil and rock properties. More advanced tomography techniques use bentray and wave front analysis in an iterative approach.5 1048 240 1339 546 1358 836 736 529 1534 1018 385 1465 1298 1304 1041 905 1483 172 347 1401 774 203 504 1576 443 528 570 1183 21 589 420 178 1255 911 998 1373 691 923 1201 445 811 1421