Analysis of surface waves from the light weight deflectometer
Författare
Summary, in English
The combination of high strain modulus from conventional light weight deflectometer (LWD) analysis and low strain modulus front LWD-induced seismic analysis would move the pavement community towards field characterization of non-linear soil stiffness for use in mechanistic-empirical pavement design. This paper explores the experimental and numerical analysis of surface seismic waves during conventional light weight deflectometer testing. Field experiments were conducted on clay, silt and gravel soils to characterize the nature of LWD-induced surface waves and to determine both low and high strain moduli. The usable high frequency limit was found to be 300 Hz for LWD-induced surface waves, enabling the low strain modulus Characterization of the top 0.3-0.5-m-thick soil layer. A numerical investigation revealed that modal interference is a significant contributor to near field effects, and that a distance of one wavelength between the LWD center and receiver array center is required to minimize these effects. The LWD-induced surface wave strain levels at a 1 m offset from the LWD were found to be on the order of 10(-2) to 10(-3)% compared to the 10(-3) to 10(-4)% strain levels associated with conventional small hammer-induced surface waves. The measured low and high strain modulus compares well with published modulus reduction functions. (C) 2009 Elsevier Ltd. All rights reserved.
Avdelning/ar
Publiceringsår
2009
Språk
Engelska
Sidor
1134-1142
Publikation/Tidskrift/Serie
Soil Dynamics and Earthquake Engineering
Volym
29
Issue
7
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Geotechnical Engineering
Nyckelord
- Quality control
- Soil dynamics
- Soil compaction
- Earthwork
- Light weight deflectometer
- Surface waves
- Seismic measurements
- Quality
- assurance
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0267-7261