Location
San Diego, California
Presentation Date
26 May 2010, 4:45 pm - 6:45 pm
Abstract
After the Bhuj earthquake the national capital region of Delhi attracted major attention of several scientific studies in the recent times. Since Delhi falls in zone IV (IS 1893: 2002) with high seismic activity, there is a great need for site characterization and seismic hazard mapping of the area. Multi Channel Analysis of Surface Wave (MASW) tests were done in Delhi at 118 sites in predefined grids of 2kmX3km each. Shear-wave velocity, VS, is an important parameter for evaluating dynamic behavior of soil. This test carried outdone using 48 channel digital seismograph with 4.5 Hz geophones. Data was analyzed using SeisImager/SW software and two dimensional shear wave velocity models at every 5m depth from ground surface was developed. It is observed that the value of Vs is ranging from 400 to 480 m/s in the rocky sites, it is 120 to 250m/s in trans Yamuna region and 250 to 370m/s in western side of the area. The shear wave velocity values are exactly matching with the geological and geotechnical characteristics of the subsoil strata. Also, the field shear wave velocity from MASW test is compared with the estimated values using the empirical formulae developed. It is observed that the experimental shear wave velocity and the empirically estimated values are almost equal up to 20m depth. But at depths greater 20m, Vs from MASW test are slightly higher than the calculated value using empirical formulae developed. Average shear wave velocity at 30m depth i.e., VS30 is also calculated and is ranging from 185 to 495 m/s for Delhi region. Also, correlations among Vs, SPT ‘N’, depth ‘D’ are developed using the available borehole data. These correlations are useful to estimate the shear wave velocity at any depth with out performing the actual test in Delhi region.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
5th International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Publisher
Missouri University of Science and Technology
Document Version
Final Version
Rights
© 2010 Missouri University of Science and Technology, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Document Type
Article - Conference proceedings
File Type
text
Language
English
Recommended Citation
Satyam, D. Neelima and Rao, K. S., "Multi Channel Analysis of Surface Wave (MASW) Testing for Dynamic Site Characterization of Delhi Region" (2010). International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. 1.
https://scholarsmine.mst.edu/icrageesd/05icrageesd/session01b/1
Included in
Multi Channel Analysis of Surface Wave (MASW) Testing for Dynamic Site Characterization of Delhi Region
San Diego, California
After the Bhuj earthquake the national capital region of Delhi attracted major attention of several scientific studies in the recent times. Since Delhi falls in zone IV (IS 1893: 2002) with high seismic activity, there is a great need for site characterization and seismic hazard mapping of the area. Multi Channel Analysis of Surface Wave (MASW) tests were done in Delhi at 118 sites in predefined grids of 2kmX3km each. Shear-wave velocity, VS, is an important parameter for evaluating dynamic behavior of soil. This test carried outdone using 48 channel digital seismograph with 4.5 Hz geophones. Data was analyzed using SeisImager/SW software and two dimensional shear wave velocity models at every 5m depth from ground surface was developed. It is observed that the value of Vs is ranging from 400 to 480 m/s in the rocky sites, it is 120 to 250m/s in trans Yamuna region and 250 to 370m/s in western side of the area. The shear wave velocity values are exactly matching with the geological and geotechnical characteristics of the subsoil strata. Also, the field shear wave velocity from MASW test is compared with the estimated values using the empirical formulae developed. It is observed that the experimental shear wave velocity and the empirically estimated values are almost equal up to 20m depth. But at depths greater 20m, Vs from MASW test are slightly higher than the calculated value using empirical formulae developed. Average shear wave velocity at 30m depth i.e., VS30 is also calculated and is ranging from 185 to 495 m/s for Delhi region. Also, correlations among Vs, SPT ‘N’, depth ‘D’ are developed using the available borehole data. These correlations are useful to estimate the shear wave velocity at any depth with out performing the actual test in Delhi region.
