Seismic Pore Water Pressure Relief Wells for Gravel Column–Bed System
DOI:
https://doi.org/10.5614/j.eng.technol.sci.2017.49.1.4Keywords:
gravel bed, gravel columns, liquefaction, pore pressure dissipation, pore pressure generation, relief wells, residual pore pressure, stone column.Abstract
Liquefaction mitigation can be achieved by dissipating seismic pore pressures. The research reported in this paper elaborates the effectiveness in dissipating seismic pore pressures of a gravel bed and relief well system using gravel columns in a case study in Cilacap, Indonesia. Seismic pore pressure generation was analyzed using commonly available methods in liquefaction analysis. The evaluated pore pressures in the sand layer and gravel columns were used in a 2D dissipation analysis using finite-difference consolidation equation solutions. The results of this study showed that a simple and cost-effective relief well and gravel bed or strip system can effectively dissipate excess pore pressures in the sand layer and gravel columns to a maximum residual pore pressure below 40%, thus reducing liquefaction potential as well as protecting the foundations in the sand.Downloads
References
Mitchell, J.K. & Huber, T.R., Performance of a Stone Column Foundation, Journal of Geotechnical Engineering, ASCE, 111(2), pp. 205-223, 1985.
Dobson, T., Case Histories of the Vibro Systems to Minimize the Risk of Liquefaction, Soil Improvement - a Ten Year Update, Welsh, J.P. (ed.), ASCE Geotechnical Special Publication, 12, pp.167-183, 1987.
Mitchell, J.K. & Wentz, F.J., Performance of Improved Ground during the Loma Prieta Earthquake, University of California, Berkeley UCB/EERC Report 91/12, 1991.
Hayden, R.F. & Baez, J.I., State of Practice for Liquefaction Mitigation in North America, International Workshop on Remedial Treatment of Liquefiable Soils, Tsukuba Science City, Japan, July 4-6, 1994.
Hausler, E.A. & Koelling, M., Performance of Improved Ground during the 2001 Niscqualli Earthquake, 5th International Conference on Case Histories in Geotechnical Engineering, NY, USA, April 13-17, Paper No. 327, 2004.
Young, R., Gibson, M. & Newby, G., Seismic Performance of Ground Improvements on Christchurch Southern Motorway, Australian Geomechanics, Australian Geomechanics Society, 47(4), December 2012.
Mahoney, D.P. & Kupec, J., Stone Column Ground Improvement Field Trial: A Christchurch Case Study, Proc. New Zealand Society for Earthquake Engineering Conference, Paper No. O79, March 2014.
Toha, F.X., Increase of In-Situ Measured Shear Wave Velocity in Sand with Displacement Pile and Stone Column Inclusions, Jurnal Teknik Sipil FTSL ITB, 24(1), 2017.
Baez, J.I. & Martin, G.R., Advances in the Design of Vibro-Systems for Improvement of Liquefaction Resistance, Proc. Symposium on Ground Improvement, Canadian Geotechnical Society, Vancouver, 1993.
Goughnour, R.R., & Pestana, J.M., Mechanical Behavior of Stone Columns under Seismic Loading, Proc., 2nd International Conference on Ground Improvement Techniques, CI-Primer, Singapore, pp. 157-162, 1998.
Rayamajhi, D., Ashford, S.A., Boulanger, R.W. & Elgamal, A., Dense Granular Columns in Liquefiable Ground: I: Shear Reinforcement and Cyclic Stress Ratio Reduction, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 142(7), Paper No. 04016023, 2016
De Alba, P., Seed, H.B. & Chan, C.K., Sand Liquefaction in Large Scale Simple Shear Tests, Journal of the Geotechnical Engineering Divison, ASCE , 102(9), pp. 909-927, 1976.
De Alba, P., Chan, C.K. & Seed, H.B., Determination of Soil Liquefaction Characteristics by Large-Scale Laboratory Tests, Report No. EERC 75-14, Earthquake Engineering Research Center, University of California, Berkeley, 1975.
Seed, H.B, Martin, P.P. & Lysmer, J., The Generation and Dissipation of Pore Water Pressures during Soil Liquefaction, Report No. EERC 75-26, Earthquake Engineering Research Center, University of California, Berkeley, 1975.
Seed, H.B. & Booker, J.R., Stabilization of Potentially Liquefiable Sand Deposits Using Gravel Drains, Journal of the Geotechnical Engineering Division, ASCE, 103(7), pp. 757-768, 1977.
Sengara, I.W., Site Specific Seismic Study, RFCC Cilacap Engineering Project, Cilacap, 2012. Unpublished.
Abrahamson, N.A. & Silva, W.J., Empirical Ground Motion Models, report prepared for Brookhaven National Laboratory, New York, NY, 1996.
Seed, H.B. & Idriss, I.M., Simplified Procedure for Evaluating Soil Liquefaction Potential, Journal of the Soil Mechanics and Foundations Division, ASCE, 107(SM9), pp. 1249-1274, 1971.
PT Pertamina, CAP Design Report Area 8 RX-RG Tower, RFCC Project, Pertamina RU-IV, Cilacap, Report No. RFCC-A-CV-RP-018, 2012. Unpublished.
Team for Indonesian Seismic Map 2010 Revision, and Team for Ground Response Development and Risk Coefficient, Indonesian Seismic Zoning Map, Indonesian Design Spectra, Ministry of Public Works, http://puskim.pu.go.id/Aplikasi/desain_spektra indonesia 2011/, July 2010. (Text in Indonesian).
Ashford, S., Rollins, K., Bradford, S., Weaver, T. & Baez, J., Liquefaction Mitigation Using Stone Columns Around Deep Foundations: Full-Scale Test Results, Journal of the Transportation Research Board, 1736, Paper No. 00-1408, pp. 110-118, 2000.
