Liquefaction Potential Analysis Along Coastal Area of Bengkulu Province due to the 2007 Mw 8.6 Bengkulu Earthquake
Keywords:Bengkulu, coastal area, liquefaction, sandy soil, strong earthquake.
AbstractThis paper presents a seismic response analysis study of liquefiable sites along the northern parts of the coastal area of Bengkulu Province that underwent liquefaction phenomena during the strong earthquake (8.6 Mw) on 12 September 2007. Several investigation tests, including the standard penetration test (SPT) and the soil shear wave velocity test, were conducted at 8 locations. The data were used to simulate the seismic response in order to investigate soil behaviors during the earthquake. In addition, the excess pore water pressure ratio obtained from the analysis was compared with the prediction value calculated from empirical data. The results show that liquefaction can occur at shallow depth layers dominated by loose sand. The results also confirm field evidence collected during the earthquake that was reported in several previous studies. The excess pore water pressure ratio was in good agreement with the predicted value from the empirical approach.
Konca, A.O., Avouac, J.P., Sladen, A., Meltzner, A.J., Sieh, K., Fang, P., Li, Z., Galetzka, J., Genrich, J., Chlieh, M. & Natawidjaja, D.H., Partial Rupture of a Locked Patch of the Sumatra Megathrust during the 2007 Earthquake Sequence, Nature, 456(7222), pp. 631-635, December. 2008.
Alif, S.M., Meilano, I., Gunawan, E. & Efendi, J., Evidence of
Postseismic Deformation Signal of the 2007 M8.5 Bengkulu
Earthquake and the 2012 M8. 6 Indian Ocean Earthquake in
Southern Sumatra, Indonesia, based on GPS Data, Applied
Geodesy, 10(2), pp. 103-108, 2016.
Misiniyati, R., Mawardi, Besperi, Razali, M.R. & Muktadir, R., Mapping of Liquefaction Potential of Coastal Area Using Cone Penetration Test in Lempuing, Bengkulu City, Inersia, 5(2), pp. 1-8, 2013. (Text in Indonesian and abstract in English).
Monalisa, A., Liquefaction Probability Analysis of Lempuing Bengkulu, Final project, Civil Engineering, University of Bengkulu, 2014. (Text in Indonesian and abstract in English).
Mase, L.Z, & Sari, A.N., A Preliminary Evaluation of Liquefaction Potential of Sandy Soil in Lempuing Sub-district (A Coastal Area in Bengkulu City), Inersia, 7(2), pp. 21-25, 2015. Text in Indonesian and abstract in English).
Mase, L.Z. & Somantri, A.K., Analysis of Liquefaction Potential in Lempuing Sub-district, Bengkulu City Using Critical Maximum Acceleration, Potensi, 25(1), pp. 1-11, 2016. (Text in Indonesian and abstract in English).
Mase, L.Z. & Somantri, A.K., Liquefaction Study Using Shear Wave Velocity (Vs) Data in Coastal Area of Bengkulu City, Proceeding of Geotechnics National Seminar, Yogyakarta, pp. 81-86, 2016.
Seed, H.B. & Idriss, I.M., Simplified Procedure for Evaluating Soil Liquefaction Potential,Soil Mechanics and Foundations Division ASCE, 97(SM9), pp. 1249-273, 1971.
Idriss, I.M. & Boulanger, R.W., Semi-empirical Procedures for Evaluating Liquefaction Potential during Earthquakes, Soil Dynamics and Earthquake Engineering. 26(1), pp. 115-30, 2006.
Earthquake Engineering Research Institute (EERI), Learning from Earthquakes Observation on the Southern Sumatra Earthquakes of September 12-13, 2007, EERI Special Report, Earthquake Engineering Research Institute, California, September 2007.
Ishihara K., Tatsuoka, F., & Yasuda, S., Undrained Deformation and Liquefaction of and under Cyclic Stresses, Soils and Foundation, 15(1), pp. 29-44, 1975.
Elgamal, A., Yang, Z., & Lu, J., Cyclic1D: a Computer Program for Seismic Ground Response, Technical Report, TR-No. SSRP-06/05, University of California at San Diego, California, 2015.
Iai, S., Matsunaga, Y, & Kameoka, T., Strain Space Plasticity Model for Cyclic Mobility, Soils and Foundations, 32(2), pp. 1-15, 1992.
Sawada, S., Ozatsumi, O., & Iai, S., Analysis of Liquefaction Induced Residual Deformation for Two Types of Quay Walls: Analysis by "FLIP" , 12th World Conference in Earthquake Engineering, January-February 2000.
Iai, S., Matsunaga, Y. & Kameoka, T., Analysis of Undrained Cyclic Behaviour of Sand under Anisotropic Consolidation, Soils and Foundations, 32(2), pp.16-20, 1992.
Liao, S.C., Veneziano, D., & Whitman, R.V., Regression Models for Evaluating Liquefaction Probability, Geotechnical Engineering ASCE, 114(4), pp. 389-410, April. 1988.
Chen, C.J., & Juang, C.H, Calibration of SPT-CPT based liquefaction Evaluation Methods, Innovations Applications in geotechnical site characterization, ASCE, 97(Special Edition), pp. 49-64, 2000.
Yegian, M.K., & Vitteli, B.M., Analysis of liquefaction: empirical Approach, Proceeding of the 1st International Conference on Recent Advance in Geotechnical Earthquake Engineering and Soil Dynamics, Missouri, April-May 1981.
National Earthquake Hazard Reduction Program (NEHRP), Recommended Provisions for Seismic Regulation for New Buildings and other Structures 1997 edition, Technical Report, FEMA 302, Federation Emergency Management Agency, Washington 1998.
Centre of Earthquake Strong Motion Data (CESMD), Earthquake Data of the 2007 Sumatra Earthquake for Sikulai Island Data, https://www.strongmotioncenter.org. (Accessed on 13 April 2017)
Youngs, R.R., Chiou, S-J., Silva, W.J, & Humprey, J.R., Strong Ground Motion Attenuation Relationships for Subduction Zone Earthquakes, Seismological Research Letter, 68(1), pp. 58-73, 1997.
Morita, T., Iai, S., Hanlong, L., Ichii, K., & Sato, Y., Simplified Parameter to Determine Parameter of FLIP, Technical Report, TR No. 869, Port and Harbour Research Institute, Yokohama, June 1997. (Text in Japanese)