The MASW method is used to record and analyze the Rayleigh wave propagation. Similar to the seismic refraction study, the source wave is emitted from the artificially generated source and earth response is recorded with the geophones arranged 1-2 m apart. As a result of the analysis, average S-wave velocity down to 30m (Vs30 ) is investigated.
In the field study; According to the situation of the field, different geophone intervals and offset should be tested to determine whether dispersion is obtained from the measured data. Source can be generated by sledgehammer or by weight reduction.
In practice, One line is surveyed at each field. At the stage of interpretation of the data, the Vs-depth model obtained from a single line may not be reliable.
A minimum of three measurements are recommended for each work. Measurements along the line always control each other and a pseudo 2D section can be obtained with the help of layered (1D) models.
Research depth (d) can be estimated from the dispersion (VD) curve by frequency-depth conversion,
d = VD / (2 f)
If the VD-frequency (f) curve is long enough, the investigated depth increases proportionally.
1D Inverse Solution
While investigating the presence of layers in 1D modeling studies, due to the characteristics of the method, a very different model can be obtained.