A Tool for Processing and Inversion of MASW Data and a Study of Inter-session Variability of MASW

Abstract

Multichannel analysis of surface waves (MASW) is a noninvasive active-source technique for determination of near-surface shear wave velocity (VS) profiles. Here we introduce and describe MASWavesPy, an open-source Python package for processing and inverting MASW data, whose design follows an object-oriented paradigm. To assess the performance of the new tool, measurements were conducted at four benchmark sites in Norway, characterized as silt, soft clay, silty sand, and quick clay. The results show that the VS profiles obtained with MASWavesPy compare well with those obtained previously at the respective sites using invasive, noninvasive and laboratory techniques. Furthermore, the efficiency and usability of the new package is superior to previous versions developed by same authors. The software can be accessed through the Python Package Index (PyPI) at https://pypi.org/project/maswavespy/ along with sample data. This work further explores the inter-session variability of MASW measurements for civil engineering applications at soft soil sites. For this purpose, repeated measurements were conducted over a 7-year period at a silty sand site in South Iceland and the recorded time series analyzed using the newly developed tool. The inter-session variability of the analysis results is reported in terms of Rayleigh wave phase velocity, interval VS profiles, and time-averaged VS for reference depths commonly used in practice.