I need help in a seismic refraction experiment

[abdelgowad]

Dear all,
Recently, I did a seismic refraction experiment to study the subsurface soil below a collapsed building. In this study, I put the receivers on one side of the building and shots on the other side. I need help in what software I should use to interpret the acquired data and I will be thankful if someone shares some papers concerning such experiment.
thanks in advance.

[99thpercentile]

It is unclear from your post whether you have sufficient shot locations to even perform a seismic refraction tomography (SRT) survey. What software do you normally use for your SRT surveys? I currently use Rayfract.

https://www.rayfract.com/

Be aware that SRT software will attempt to give you an answer no matter how poor your survey design was. You need to ensure a thorough understanding of the method and survey design so that your interpretation of the results from the software aligns with the physics of the problem. From your description, I would guess that you do not have enough shot locations, and that the shot geometry was poor.

[abdelgowad]

Thank you very much.
I am using the Rayfract but in the Demo version. The option to put the right geometry is inactive.
By the way, in your opinion, what is the minimum number of shots that could be enough to perform a rough SRT??
Thanks

[Pete]

Hi,
How many times you have to stack depends on your source, distance, max depth, receivers, noise etc. you just need to try.
I would suggest to run at least one parallel line just past the house and if possible a cross line. That is a full line where you place the receivers from zero offset densely towards the house to also record reflections. Then move the receivers further away on the line and repeat depending on numbers of geophones and sampling rate.

[hAJET2345]

How did the experiment go? best fence

[99thpercentile]

For SRT, the depth of investigation is approximately 1/5 of the spread length while spatial resolution is approximately 1/2 to 1x the geophone spacing. For short locations, you would typically do three off end shots for each end of the spread and shot locations every 2 to 3 geophone locations along the spread.

[resour]

Our free trial version has clearly described limitations. See our manual

https://rayfract.com/help/rayfract.pdf

on page 72 / chapter System limitations :

- will expire after 30 days or after 50 runs, whichever happens first
- supports up to 30 shots per profile only. You will need to renumber your shots as shot
number 0 to shot number 29.
- does not support topography specification
- does not allow selecting Line type Borehole spread/line in Header menu, Profile dialog
- does not support Crosshole/Downhole/Uphole/Walkaway VSP survey Smooth inversion, with WET tomography
- does not support interactive Wavepath Eikonal Traveltime WET tomography
processing
- does not support interactive pseudo-2D DeltatV and XTV inversion
- does not offer time-to-depth inversion methods Wavefront and CMP intercept-time
refraction
- does not offer Midpoint breaks display
- Trace|Midpoint gather is disabled
- does not support importing or specifying receiver station coordinates. Assumes
a straight line recorded on a flat topography.
- you need to specify shot and receiver position for horizontal refraction spread/line by station number during import of shots.
- you can select pre-defined receiver spread types or define your own receiver spread type in File menu, item New Spread type.
- does not support importing or specifying lateral shot position offsets and shot hole depths.

For our latest release notes see

https://rayfract.com/help/release_notes.pdf

[Marie143]

There are several software packages available for interpreting seismic refraction data, including SeisImager, ReflexW, and Oasis Montaj. Each of these packages has its strengths and weaknesses, and the choice of software may depend on the specific needs of your project.

fort worth texas drywall contractor If you are looking for papers related to seismic refraction experiments, there are many resources available. Some popular journals that publish research related to seismic refraction include Geophysics, Journal of Applied Geophysics, and Near Surface Geophysics. You can search for articles on these topics using academic search engines such as Google Scholar or through academic databases like JSTOR and ScienceDirect.

[resour]

For an objective comparison of Seismic Refraction Tomography (SRT) options see

Zelt, C.A., Haines, S., Powers, M.H. et al. 2013. Blind Test of Methods for Obtaining 2-D Near-Surface Seismic Velocity Models from First-Arrival Traveltimes, JEEG, Volume 18(3), 183-194. https://scholarship.rice.edu/handle/191 ... ?show=full .

Sheehan J.R., Doll W.E. and Mandell W.A. 2005a. An Evaluation of Methods and Available Software for Seismic Refraction Tomography. Journal of Environmental and Engineering Geophysics, volume 10, pp. 21-34. ISSN 1083-1363, Environmental and Engineering Geophysical Society. JEEG March 2005 issue. https://dx.doi.org/10.2113/JEEG10.1.21 . https://rayfract.com/srt_evaluation.pdf .



For an overview of our WDVS (Wavelength-Dependent Velocity Smoothing; Zelt and Chen 2016) see these publications :

Zelt, C. A. and J. Chen 2016. Frequency-dependent traveltime tomography for near-surface seismic refraction data, Geophys. J. Int., 207, 72-88, 2016. See https://dx.doi.org/10.1093/gji/ggw269 and https://www.researchgate.net/publicatio ... ction_data .

Rohdewald S.R.C. 2021a. Improving the resolution of Fresnel volume tomography with wavelength-dependent velocity smoothing, Symposium on the Application of Geophysics to Engineering and Environmental Problems Proceedings : 305-308. https://doi.org/10.4133/sageep.33-169 . Slides at https://rayfract.com/pub/SAGEEP%202021%20slides.pdf

Rohdewald S.R.C. 2021b. Improved interpretation of SAGEEP 2011 blind refraction data using Frequency-Dependent Traveltime Tomography, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4214, https://doi.org/10.5194/egusphere-egu21-4214



For recent Rayfract(R) tutorials see

https://rayfract.com/tutorials/Line3.pdf
https://rayfract.com/tutorials/NGU_G1.pdf
https://rayfract.com/tutorials/NGU_G4.pdf
https://rayfract.com/tutorials/poisson_Surfer23.pdf
https://rayfract.com/tutorials/3016.pdf
https://rayfract.com/tutorials/TRA9002_ ... n_test.pdf
https://rayfract.com/tutorials/SR6.pdf
https://rayfract.com/tutorials/11REFR.pdf
https://rayfract.com/tutorials/mdw2011.pdf


For our latest release notes see

https://rayfract.com/help/release_notes.pdf