Soil Void Ratio Correlation with Shear Wave Velocities and SPT-N Values for Indo-Gangetic Basin Anbazhagan, P., Anjali Uday, Sayed S.R. Moustafa, Nassir S.N. Al-Arifi, 2017, Journal of Geological Society of India.
Presenter : Chun-Liang Kuo Advisor : Prof. Jia-Jyun Dong Date : 2020.05.29 Outline
• Introduction • Methodology • Result and Discussion • Conclusion
2 Introduction
3 Indo-Gangetic Basin
Home for more than 200 million people
Alluvium sediments deposited due to river
Holocene and Pleistocene Liquefaction is a major geotechnical hazard in the IGB
Active Himalayan Belt and young river deposits
4 Importance of Void Ratio ( e ) Permeability
푉 Void Ratio (e) 푒 = 푣표푖푑 푉푠표푙푖푑 Strength of soil
Air 푉 Water 푣표푖푑 Deformation characteristics Solid 푉푠표푙푖푑
Liquefaction evaluation
5 How to get void ratio value ?
1 Large study area Drill borehole Limited data
Need more data for Sampling higher accuracy
But you can’t drilling Conduct experiment 2 Calculation Estimate form other parameters Void Ratio
6 Previous correlation with void ratio
Correlation with Soil Sample Reference Shear wave velocity Cunning et al. 1995 Reconstitute Ottawa sand form Hardin and Richart 1963 Shear wave velocity and effective laboratory mean normal stress Hardin and Drnevich 1972 Normalized shear wave velocity In-situ soil Chang and Heymann 2005 against effective normal stress
Limited studies correlate with in-situ void ratio
7 Objective
1. Develop correlation between in-situ void ratio and shear wave velocity, SPT-N value.
8 Methodology
9 Field Testing - Vs measurement
Multichannel Analysis of Surface Wave Lucknow 21 Vs profile ( MASW)
10 Field Testing – SPT N, e measurement
Lucknow 23 borehole data
Bhagalpur How many hit 23 borehole data 15cm N1 Gurgoan 6 borehole data N2 N3
Barauni SPT N values : N2+N3 32 borehole data
Sampling tube 11 Regression analysis
Correlation with e and Vs Correlation with e and N
202 Data sets 293 Data sets
Fine Coarse Fine Coarse All Soil All Soil Grained Grained Grained Grained
푏 푏 Regression form : 푒 = 푎 (푉푠 ) Regression form : 푒 = 푎 ( 푁 )
푎, 푏 푎푟푒 푟푒푔푟푒푠푠푖표푛 푐표푒푓푓푖푐푖푒푛푡푠
12 Result and Discussion
13 Void Ratio Correlate With Shear Wave Velocity
For all soil types For fine grained soil For coarse grained soil
202 Data sets 128 Data sets 74 Data sets −0.41 −0.261 −0.398 푒 = 6.74푉푠 푒 = 2.73푉푠 푒 = 6.887푉푠 푅2 = 0.713 푅2 = 0.695 푅2 = 0.66
14 Void Ratio Correlate With SPT-N
For all soil types For fine grained soil For coarse grained soil
293 Data sets 190 Data sets 103 Data sets 푒 = 1.202푁−0.217 푒 = 0.89푁−0.12 푒 = 1.01푁−0.105 푅2 = 0.736 푅2 = 0.71 푅2 = 0.729
15
Prediction Performance
Void ratio predicted Vs by predicted ratio Void Void ratio predicted N by predicted ratio Void
Measured void ratio Measured void ratio
16 Preliminary estimate for Liquefaction susceptibility
Zone of liquefaction Zone of liquefaction
e = 0.7 e = 0.6
N = 25 Vs = 250 m/s Value taken from ( Idress and Boulanger 2008 )
17 Conclusion
18 Conclusion 1. Data obtained from MASW and SPT were used in developing new correlations between in-situ void ratio, SPT-N, Vs.
2. Different correlations were developed for all soil types, fine grained and coarse grained. For all soil types For fine grained soil For coarse grained soil
−0.41 −0.261 −0.398 푒 = 6.74푉푠 푒 = 2.73푉푠 푒 = 6.887푉푠 푅2 = 0.713 푅2 = 0.695 푅2 = 0.66
19 Conclusion
3. Statistical validation and graphical comparison indicate good
prediction capability.
Void ratio predicted Vs by predicted ratio Void Void ratio predicted N by predicted ratio Void
Measured void ratio Measured void ratio 20 Conclusion
4. This study shows that sites in IGB may be susceptible to liquefaction if in-situ void ratio is more than 0.6.
Zone of liquefaction Zone of liquefaction
e = 0.7 e = 0.6
N = 25 Vs = 250 m/s Value taken from ( Idress and Boulanger 2008 ) 21 Thank you for your attention
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