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International Journal of Civil Engineering and Technology (IJCIET) Volume 10, Issue 03, March 2019, pp. 852-858, Article ID: IJCIET_10_03_082 Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=10&IType=03 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed ESTIMATION OF THE SHEAR WAVE VELOCITY FOR INDORE CITY USING VARIOUS CORRELATIONS Deepshikha Shukla PhD Scholar, Applied Mechanics Department, SVNIT, Surat - 395007 Chandresh H. Solanki Professor, Applied Mechanics Department, SVNIT, Surat - 395007 ABSTRACT Shear modulus of the different types of soils can be estimated using the shear wave velocity (Vs) measured by the correlations between the Shear Wave Velocity (Vs) and the Standard Penetration Tests (SPT-N values). The correlations between the two parameters have been proposed by various researchers in the past. The shear wave velocity is a measure of shear modulus of soil and is used for the measurement of parameters for geotechnical earthquake engineering. The method of applying an appropriate method of correlation between SPT-N values and shear wave velocity is an approximate method applied when the precise measurement of Vs seems to be difficult and therefore the value can be estimated using the correlation of the SPT-N value of the soil. Many correlations have been developed and suggested by the researchers in the past based on the soil profile, characteristics of the soil and geology of the site. In the current study, shear wave velocity at nine locations in and around Indore City have been estimated using 21 correlations including the one recommended for the Indian soil sites. Keywords: Borelog Data, SPT-N Values, Shear Wave Velocity Cite this Article: Deepshikha Shukla and Chandresh H. Solanki, Estimation of the Shear Wave Velocity for Indore City Using Various Correlations, International Journal of Civil Engineering and Technology, 10(03), 2019, pp. 852–858 http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=10&IType=03 1. INTRODUCTION Past many years Peninsular India (PI) was assumed to be a silent and non-hazardous but over a decade, this scenario has changed and due to the occurrence of many earthquake events and other natural hazardous events, PI is now catching attention of all the researchers in and around India specially after the Killari 1933 (Mw = 6.1) and Koyna 1967 (Mw = 6.3) earthquakes in http://www.iaeme.com/IJCIET/index.asp 852 [email protected] Estimation of the Shear Wave Velocity for Indore City Using Various Correlations India. Various mathematical and computational approaches have been suggested by researchers globally and have been applied over various regions for the hazard assessment and its computation. As soil profile and its characteristics play a major role in the hazards it is indeed important to carry out detailed studies of the soil samples from various locations. Assessment of dynamics properties of soil needs to be carried out for detailed soil investigation and for this various methods are available. Estimation of Shear Wave velocity by conducting tests such as Multichannel Shear Wave Velocity (MASW) is yet another widely used noninvasive method for the computation of the dynamic properties of soil for that location. In case MASW test cannot be performed approximate or empirical method for the computation of the shear wave velocity by using the correlations between the Standard Penetration Tests (SPT) N Values and Shear Wave Velocity (Vs) suggested by various authors can be used or a new correlation for the area can be developed. Hence, in this study an attempt has been made to estimate the Shear Wave Velocity by using the SPT-N values for two borehole locations and the average value of the shear wave velocity thus obtained is matched with the existing correlations suggested by the authors. The coordinates of the borehole locations were marked and represented over the Geographical Information System (GIS) platform which is a computer based information system that captures the data over the coordinate system and the captured data can be later used for georeferencing, representation, and manipulation of the data. The GIS tool is rapidly gaining pace in the digitization of the facts and figures and for the preparation of the digitized maps. 2. STUDY AREA Indore city is situated in the Central part of India in the state of Madhya Pradesh with (22.71960N and 75.85770E) as the geographical coordinates. This region lies in Seismic Zone III as per Zonation Map of India and also lies in the Malwa Region having a lot of Flora and Fauna in and around the Indore City. This city is coming up as a Smart City with a lot of infrastructural development is taking place. It is also the commercial head of the State with a lot manufacturing units operating in the area. Considering the importance of this city in all respects it becomes imperative to carry out the studies pertaining to the hazard analysis and soil properties. 3. METHODOLOGY ADOPTED Soil Borehole data were collected from about 172 different locations in and around the Indore City. The data collected from these locations was then compiled along with the engineering properties of soil such as SPT-N value, specific gravity, density, depth of water table, plasticity index and moisture content. The borehole locations are plotted using the GIS technology and GIS software is used for the creation of the digitized maps of the study area. The shear wave velocities are estimated from the SPT-N values using the correlations suggested by various authors. The average shear wave velocity as computed for various depths is then compared with the existing relationships to check the suitability of the equation. The digitized map of Indore city with nine major borehole locations is plotted with the average shear wave velocity over the entire borehole depth as shown in fig 1. http://www.iaeme.com/IJCIET/index.asp 853 [email protected] Deepshikha Shukla and Chandresh H. Solanki Figure 1 Digitized map showing the Average Shear Wave velocity of nine major locations near Indore In the present study, the different correlations as suggested by the researchers are tabulated below in table 1. These correlations are used for the estimation of the shear wave velocity for the SPT N value for each borehole data. Few correlations as proposed by Indian authors for all Indian soil types are: (i) Vs = 72*N0.4 - Mhaske and Deepankar (2011) for Mumbai Region (ii) Vs = 82.6*N0.43 – Hanumanthrao and Ramana (2008) for Delhi Region (iii)Vs = 78(N60cs)0.4 – Sitharam and Anbazhagan (2008) for Bengaluru Region Where Vs – Shear wave Velocity (m/s) and N – measure SPT N value from borehole data and N60cs is the corrections applied for the type of hammer, sampler, rod length, borehole diameter etc. The corrected value of N is obtained after applying these corrections and finally can be computed for the estimation of Vs value using the correlation suggested by Sitharam and Anbazhagan (2008) for Bengaluru Region. The SPT N value obtained from borehole data for Indore region is then finally compared to match with the existing correlations. However, in this process the correlation suggested by Sitharam and Anbazhagan (2008) for Bengaluru Region is not used for the estimation of the Shear Wave Velocity. http://www.iaeme.com/IJCIET/index.asp 854 [email protected] Estimation of the Shear Wave Velocity for Indore City Using Various Correlations Table 1 Proposed Correlations between SPT-‘N’ Values and Shear Wave Velocity ‘Vs’ S.No. Correlations between SPT-N Values and Shear Wave Velocity (m/s) 1. Vs = 72*N0.4 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. Vs = 82.6*N0.43 Vs = 68.3*N0.292 Vs = 51.5*N0.516 Vs = 57.4*N0.49 Vs = 114.43*N0.31 for clay Vs = 116.1*(N + 0.3185)0.202 Vs = ((5.3*N)+134) for clay and silty clay Vs = ((5.1*N)+152) for sand and gravelly sand Vs = 100.5*N0.29 Vs = 97*N0.314 Vs = 61*N0.5 Vs = 80*N1/3 for sand Vs = 100*N1/3 for clay Vs = 85.35*N0.348 Vs = 91*N0.337 Vs = 80.2*N0.292 for clay Vs = 82*N0.39 Vs = 92.1*N0.337 Vs = 84*N0.31 Vs = 76*N0.33 Proposed By Mhaske & Deepankar Choudhary (2011) Hanumanthrao and Ramana (2008) Kiku et. Al. (2001) Iyisan (1996) Lee (1990) Lee (1990) Jinan (1987) Fumal & Tinsley (1985) Fumal & Tinsley (1985) Sykora & Stoke (1983) Imai & Tonouchi (1982) Seed and Idriss (1981) JRA (1980) JRA (1980) Ohta & Goto (1978) Imai (1977) Imai (1977) Ohsaki & Iwasaki (1973) Fujiwara (1972) Ohba & Toriumi(1970) Imai & Yoshimura (1970) 4. RESULTS The estimated shear wave velocities for all soil types in Indore Region is calculated using all 21 correlations based on the SPT-N values. These values thus obtained are then plotted. In the subsequent graphs, shear wave velocity is plotted for two different site locations namely the residential building located at Chhatrapati Nagar near Indore and Pharmaceutical Industry at Village Asrawad near Indore with 2 and 4 boreholes data. The range of borehole depth, SPT N values and Shear Wave Velocity is compiled below in the tabulated form. The graphs thus plotted are shown in fig 2 – 5. S.No. Name of the Site BH No 1. Residential Building located at Chhatrapati Nagar near Indore 2. Pharmaceutical Industry at Village Asrawad near Indore 1 2 1 2 http://www.iaeme.com/IJCIET/index.asp 855 Depth (m) 5 – 10 6 - 10 6–8 5 - 10 SPT N 8 – 55 5 - 53 32 – 50 35 - 60 Shear Wave Velocity (m/s) 120 – 218 120 220 185 – 212 190 - 220 [email protected] Deepshikha Shukla and Chandresh H. Solanki Shear Wave Velocity (Vs) Figure 2 Comparison of Shear Wave Velocities with other correlations for BH 1 for the location Residential Building site located at Chhatrapati Nagar near Indore 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Avg Vs 460 440 420 400 380 360 340 320 300 280 260 240 220 200 180 160 140 120 0 10 20 30 40 50 60 SPT-N Value Figure 3 Comparison of Shear Wave Velocities with other correlations for BH 2 for the location Residential Building at their site located at Chhatrapati Nagar near Indore http://www.iaeme.com/IJCIET/index.asp 856 [email protected] Estimation of the Shear Wave Velocity for Indore City Using Various Correlations 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Avg Vs 420 400 Shear Wave Velocity (Vs) 380 360 340 320 300 280 260 240 220 200 180 30 32 34 36 38 40 42 44 46 48 50 SPT-N Value Figure 4 Comparison of Shear Wave Velocities with other correlations for BH 1 for the location Construction of Pharmaceutical Industry at Village Asrawad near Indore 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Avg vs Shear Wave Velocity (Vs) 450 400 350 300 250 200 35 40 45 50 55 60 SPT-N value Figure 5 Comparison of Shear Wave Velocities with other correlations for BH 1 for the location Construction of Pharmaceutical Industry at Village Asrawad near Indore 5. CONCLUSION http://www.iaeme.com/IJCIET/index.asp 857 [email protected] Deepshikha Shukla and Chandresh H. Solanki Determining the shear wave velocity of soil is an important parameter for the study of dynamic properties of soil in geotechnical engineering. Various methods are available for determining the shear wave velocity but in the case of non-availability of the test or if the data is not large an empirical method can be used. As seen from the graphs, the plot between the average shear wave velocity and SPT N value for the boreholes the curves matches with that of the equation suggested by Fumal & Tinsley (1985) (9) for sand and gravely sand. Hence this empirical method or approximate method can be used for the estimation of the Vs using the SPT N values and the correlation. Hope these results thus obtained may be useful to the practitioners. REFERENCES [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] Park, C. B., Miller, R. D. and Xia, J. Multi-channel analysis of surface wave (MASW). Geophysics, Vol. 64(3), pp. 800-808, (1999). Angadi, S., Desai, M. K. and Dodagoudar, G. R., Development of Subsurface Profile Using Geophysical Test Data International Journal of Earth Sciences and Engineering, ISSN 0974-5904, Vol. 09, No. 03, June, 2016, pp. 161-164. (2016). Sumedh Mhaske, Deepankar Choudhary Geospatial contour mapping of shear wave velocity for Mumbai City, Nat Hazards, 59:317-327, DOI 10.1007/s11069-011-9758-z (2011) Choudhary D, Savoikar P, Equivalent-Linear Seismic Analyses of MSW landfills using DEEPSOIL, Engg Geol 107(3-4):98-108 (2009b) Boominathan A, Dodagoudar GR, Suganthi A, Maheshwari R, Uma, Seismic Hazard Assessment considering local site effects for microzonation studies of Chennai City, A workshop on microzonation Interline Publishing, Bangalore, Inda pp 94-109 (2006) Miller R.D., Xia J., Park C.B., Multichannel analysis of surface waves to map bedrock, The leading Edge, Vol 18(12), pp. 1392-1396, (1999) Hanumanthrao C, Ramana GV, Dynamic Soil properties for microzonation of Delhi, India, Journal of Earth Syst Sci 117(S2):719-730 Mhaske SY, Choudhary D, GIS based soil liquefaction susceptibility map of Mumbai city for earthquake events, Journal of applied Geophysics 70(3):216-225 Iyisan R, Correlations between shear wave velocity and in situ penetration test results (In Turkish), Chamber of Civil Engineers of Turkey, Teknik Dergi 7(2):1187-1199 (1996) Sitharam TG, Anbazhagan P, Site characterization using geotechnical and geophysical techniques for seismic microzonation of urban areas, In Proceedings of international geotechnical conference on development of urban areas and geotechnical engineering, Saint Petersburg, Russia I:131-147 (2008) Sitharam TG, Anbazhagan P, Seismic hazard analysis for the Bangalore region, Natural Hazards 40:261-278 (2007) Ohta Y, Goto N, Empirical shear wave velocity equations In terms of characteristics soil indexes, Earthquake Engineering and Structure Dynamics 6:167-187 Jinan Z, Correlation between seismic shear wave velocity ad the number of blows of SPT and depth, selected papers from the Chinese Journal of Geotechnical Engineering, ASCE, 92-100 (1987) http://www.iaeme.com/IJCIET/index.asp 858 [email protected]