PENGARUH KERAPATAN TANAH PASIR KALI OPAK PLERET YOGYAKARTA TERHADAP POTENSI LIKUIFAKSI BERDASARKAN UJI SHAKING TABLE

Bimawijaya  Laia

Bimawijaya Laia STKIP Nias Selatan

Abstract views: 0 ,

Fultext downloads: 0

Keywords: likuifaksi, uji shaking table, kerapatan relatif, rasio peningkatan tegangan air pori

Abstract

Likuifaksi adalah suatu peristiwa berubahnya sifat tanah dari keadaan padat menjadi keadaan cair, yang disebabkan oleh beban siklik pada saat gempa terjadi sehingga tekanan air pori meningkat melebihi tegangan efektif tanah. Likuifaksi umumnya terjadi di lapisan sedimen granular dengan tingkat kerapatan rendah. Pengaruh kerapatan relatif tanah terhadap mekanisme likuifaksi dapat diketahui dengan melakukan uji eksperimental menggunakan shaking table. Parameter yang digunakan untuk menentukan tanah yang mengalami likuifaksi adalah rasio peningkatan tegangan air pori (r_u). Jika r_u ≥ 1 maka likuifaksi dapat terjadi, sedangkan jika r_u < 1 maka likuifaksi tidak dapat terjadi. Tanah pasir Kali Opak Pleret yang digunakan sebagai objek dalam penelitian memiliki kerapatan sebesar 24,35%. Hasil evaluasi uji shaking table menunjukkan bahwa potensi likuifaksi terbesar terjadi pada kerapatan relatif tanah 25% untuk percepatan gempa 0,4g dan terendah tercatat pada kerapatan relatif tanah 55% untuk percepatan gempa 0,3g. Penurunan muka tanah terbesar terjadi pada kerapatan relatif 25% yakni 4 cm dan terendah pada kerapatan 55% sebesar 0,53 cm. Pengujian ini menunjukkan bahwa pada tanah pasir Kali Opak Pleret dengan kerapatan relatif tanah 25% dan 35% berpotensi likuifaksi, dan pada kerapatan relatif tanah 45% dan 55% tidak berpotensi likuifaksi.

References

Adi, A.D., 2013, Identifikasi Potensi Likuifaksi Tanah Untuk Penyiapan Pengembangan Lahan, Proceeding 17th Annual Scientific Meeting, Indonesian Society For Geotechnical Engineering, pp. 211-216.
American Society for Testing Materials (ASTM), 2000, Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table (D 4253-00), 100 Barr Harbor Drive, West Conshohocken, United States.
Barker, J.A., 1981, Dictionary of Soil Mechanics and Foundation Engineering, Longman Group, United Kingdom.
Bolt, B.A., 1993, Earthquakes, W.H. Freeman and Company, USA.
Borgomeo, E., Di Capua, G., and Peppoloni, S., 2010, An Overview of Earthquake Related Liquefaction Events in Italy, Miscellanea INGV, Istituto Nazionale di Geofisica e Vulcanologia, Roma.
Boulanger, R.W., Kamai, R., and Ziotopoulou, K., 2013, Liquefaction Induced Strength Loss and Deformation Simulation and Design, Bulletin Earthquake Eng.
Cornforth, D.H., 2005, Landslide in Practice: Investigation, Analysis and Remedial/Preventative Option in Soils, John Wiley & Sons, Inc., Hoboken, New Jersey.
Das, B.M., and Ramana, G.V., 2011, Principles of Soil Dynamics, Second Edition. Cengage Learning, Stamford, USA.
Day, R.W., 2002, Geotechnical Earthquake Engineering Handbook, McGraw-Hill, New York.
Elgamal, A. W., Dobry, R., and Adalier, K. (1989), Study of Effects of Clay Layers on Liquefaction of Sand Deposits Using Small-Scale Models, Proceedings 2nd US-Japan Workshop on Liquefaction, Large Ground Deformation and Their Effects on Lifelines, pp. 145-160.
Elnashai, A.S., and Di Sarno, L., 2008, Fundamental of Earthquake Engineering, A John Wiley and Sons, UK.
Fathani, T.F., Adi, A.D., Pramumijoyo, S., and Karnawati, D., 2008, The Determination of Peak Ground Acceleration at Bantul Regency, Yogyakarta Province, Indonesia, The Yogyakarta Earthquake 2006, hal. 12-1 - 12-15.
Ha, I.S, Olson, S.M., Seo, M.W., and Kim. M., 2011, Evaluation Of Reliquefaction Resistance Using Shaking Table Tests, Soil Dynamics and Earthquake Engineering No. 31 pp. 682–691.
Harazika, H., Yasuhara, K., Hyodo, M., Karmokar, A.K., and Mitara, Y., 2008, Mitigation Of Earthquake Induced Geotechnical Disasters Using A Smart And Novel Geomaterial, The 14th World Conference on Earthquake Engineering, Cina.
Ikhsan R., 2011, Analisis Potensi Likuifaksi dari Data CPT dan SPT dengan Studi Kasus PLTU Ende Nusa Tenggara Timur, Tugas Akhir, Fakultas Teknik, Program Studi Teknik, Universitas Indonesia.
Ishihara, M., Okamura, M., and Ohshita, T., 2003, Desaturating Sand Deposit by Air Injection for Reducing Liquefaction Potential, 2003 Pacific Conference on Earthquake Engineering.
Japan Society of Civil Engineers, 2007, Instructions For Geotechnical Investigation and The Practical Utilization of its Results For Recovery and Reconstruction of Nias Island and For Disaster Prevention of North Sumatra and West Sumatra Province.
Kramer, S.L., 1996, Geotechnical Earthquake Engineering, Prentice Hall, Englewood Cliffs.
Lopez, F.J., 2002, Does Liquefaction Protect Overlying Structure From Ground Shaking, Dissertation, Earthquake Engineering, Instituto Unversitario di Studi Superiori di Pavia.
Mase, L.Z. 2013, Analisis Potensi Likuifaksi Di Kali Opak Imogiri Daerah Istimewa Yogyakarta (Studi Eksperimental Dan Analisis Empiris), Tesis, Jurusan Teknik Sipil (Geoteknik) dan Lingkungan, Universitas Gadjah Mada.
Michigan Department of Transportation, 2009, Uniform Field Soil Classification System (Modified Unified Description).
New York Department of Transportation, 2007, Geotechnical Design Procedure: Liquefaction Potential Of Cohesionless Soils, Geotechnical Engineering Bureau.
Özener, P.T., Özaydın, K., and Berilgen, M.M., 2009, Investigation of Liquefaction and Pore Water Pressure Development in Layered Sands, Journal Bulletin Earthquake Eng. No. 7, pp. 199–219.
Prakash, S., 1981, Soil Dynamics, McGraw-Hill Book Company, United States of America.
Prakash, S., and Puri, V.K., 2003, Liquefacation of Silts and Silt-Clay Mixtures, Taiwan Workshop on Liquefaction.
Pusat Mitigasi Bencana, 2005, Laporan Kajian Awal Dan Survey Rekonesans Pasca Gempa bumi Nias 28 Maret 2005, Lembaga Penelitian Dan Pemberdayaan Masyarakat, Institut Teknologi Bandung.
SNI 1726-2012, 2012, Tata Cara Perencanaan Ketahanan Gempa Untuk Struktur Bangunan Gedung Dan Non Gedung, Badan Standardisasi Nasional.
Tsuchida, H., 1970, Prediction and Countermeasure against Liquefaction in Sand Deposits, Abstract of the Seminar of the Port and Harbour Research Institute, Ministry of Transport, Yokosuka, Japan, pp. 3.1 - 3.33.
Yogatama, B.A., 2012, Analisis Potensi Likuifaksi di Kawasan Kabupaten Bantul dan Kota Yogyakarta, Tugas Akhir, Jurusan Teknik Sipil dan Lingkungan, Universitas Gadjah Mada.
Zhang, J.M., and Wang, G., 2012, Large Post-Liquefaction Deformation Of Sand, Part I: Physical Mechanism, Constitutive Description And Numerical Algorithm, Journal Acta Geotechnica, No. 7, pp: 69–113