3D treatment of MASW data for monitoring ground improvement at an uncontrolled fill site

Abstract

The Multichannel Analysis of Surface Waves, or MASW in short (Park, et al, 1999; Suto, 2007) analyses seismic data in the frequency-velocity domain and estimates the S-wave velocity structure under the seismic receiver array. Its application range varies, commonly from only a few metres to tens of metres, depending on the wavelengths of the surface waves used for analysis. The output from an MASW survey and analysis is essentially a series of 1-dimensional S-wave velocity profiles, generating spatially discrete data points similar to borehole data. As the data are collected along a line and sampled at closely spaced intervals, it is common to present the data in the form of a 2 dimensional section of S-wave velocities along the survey line, rather than a 1 dimensional profile with depth. If an MASW survey consists of closely spaced survey lines, it is possible to present the output of the surveyed area as a 3-dimensional data set. This paper presents an example of an application of the MASW survey method at a landfill site, with data presented in plan view with a number of depth slices.