MASW applications for road construction and maintenance

Abstract

Road construction and maintenance are major parts of geotechnical engineering that deal with the stiffness of natural or manmade ground materials. At the earliest stage of new road construction, the ground along the planned route often needs to be characterized in terms of the overall stiffness of the overburden-bedrock system. During construction, multiple stages of compaction and grading of geotechnical materials occur, with each requiring stringent quality control processes to ensure necessary stiffness levels are achieved. After construction, it is often necessary to periodically monitor stiffness conditions underneath an existing road for development of underground subsidence, especially if the road was built over subsidence-prone areas. Traditional approaches to stiffness evaluation — for example, cone penetration tests and standard penetration tests — provide local results that are highly dependent on test location. A seismic method, on the other hand, can provide a macroscale evaluation of a given material's elastic properties. The multichannel analysis of surface waves (MASW) method provides information on shear-wave velocity, which is the most scientifically accurate indicator of material stiffness from an elasticity perspective. Because of the strong nature of surface waves, the MASW field survey becomes a highly tolerant operation and is almost always guaranteed to be effective, rendering the approach highly convenient and reliable. Subsequent data analysis procedures are straightforward and do not require the application of signal-enhancing techniques. Because subsurface velocity models can differ by type of application, corresponding dispersion patterns must be noted during the analysis. Case studies executed during the beginning and ending stages of road construction and during the maintenance stage of a built highway are presented.

Using Geometry Data from Ground Penetrating Radar to Improve Pavement Layers Auscultation Using Seismic Surface Waves Inversion Method

“…This reversal is explained by the decrease of velocities with the depth on the pavements. This interval [70 -200] was confirmed by the work of Park (2018) which showed that it is dependent on the length of the profile and the spread of the geophones. These results are also confirmed at various sites studied by Diene and Ndiaye (2022) with the same acquisition device.…”

“…However, the use of the MASW method as a pavement investigation method remains tedious due to several implementation factors; This led to the use of peakless geophones with the Land Streamer acquisition technique [11] [12].…”