Author : Nitesh Sambhaji Pawar 1
Date of Publication :16th May 2017
Abstract: Surface wave method was introduced as a tool to the geotechnical and infrastructure engineering fields in the early 1980’s. The non-invasive seismic method of multi-channel analysis of surface waves (MASW) is often used to map shear wave velocity variation of soil with depth. In an attempt to increase confidence in the interpreted shear wave velocity (Vs) profile as a result of the ambiguity in the analyzed dispersion characteristics, multichannel method is used in this research to characterize a test site on the ground of Veermata Jijabai Technological Institute (VJTI), Matunga, Mumbai. The multichannel analysis of surface waves (MASW) method originated from the traditional seismic exploration approach that employs multiple (twelve or more) receivers placed along a linear survey line. The present paper indicates results from MASW survey at a site along the VJTI college ground, for which the MASW data acquisition involved the use of a 12- channel PASI seismograph and a 12 nos. of 4.5-Hz Vertical geophones spaced at 5 m each and source offset 7m. The seismic source was a Sledge hammer (10 lbs). WinMasw 6.0 standard version software package was used to process and invert the Surface-wave seismic data in addition to generating the one-dimensional depth versus Shear Wave Velocity (Vs) profiles. The average shear wave velocity of the current study area is 228 m/s. The average shear wave velocity for Mumbai city is ranging from 110 to 350 m/s. The results determine, benefits of using non-invasive MASW method to construction engineering field in a cost effective and time effective manner as compared to conventional standard penetration test, drilling method.
Reference :
-
- Building seismic safety council national institute of building sciences, NEHRP recommended provisions for seismic regulations for new buildings and other structures FEMA 450 (2003), page 47
- Dr. K. R. Arora, Soil Mechanics and Foundation Engineering (2005), page no. 416.
- Dr. P. Anbazhagan, Introduction to engineering seismology, lecture 13
- http://www.masw.com/DataAcquisition.html
- Long M., and Donohue S. (2007). “In situ shear wave velocity from multi-channelanalysis of surface waves (MASW) tests at eight Norwegian research sites.” Canadian Geotechnical Journal, 44(5), 533-544.
- Mhaske SY, Choudhury D. (2011), ―Geospatial contour mapping of shear wave velocity for Mumbai city, Nat Hazards (2011) 59:317–327.
- Mumbai port trust- Schedule of rates (2011), page no. 1.
- Park, C. B., Miller, R. D., and Xia, J. (1999). Multi-channel analysis of surface waves.” Geophysics, 64(3), 800-808.
- Penumadu, D., and Park C. B. (2005). Multichannel analysis of surface wave method (MASW) for geotechnical site characterization.” American Society of Civil Engineers Geotechnical Special Publication, Issue 130, 956-967