Analisis Potensi Likuefaksi dan Perbaikan Tanah dengan Stone Column: Studi Kasus pada Coal Shelter PLTU Lontar, Banten

Yuli Fajarwati; Rama Indera Kusuma

doi:10.21831/inersia.v17i1.40570

Analisis Potensi Likuefaksi dan Perbaikan Tanah dengan Stone Column: Studi Kasus pada Coal Shelter PLTU Lontar, Banten

Yuli Fajarwati, Jurusan Pendidikan Teknik Sipil dan Perencanaan, Fakultas Teknik, Universitas Negeri Yogyakarta, Indonesia
Rama Indera Kusuma, Jurusan Teknik Sipil, Fakultas Teknik, Universitas Sultan Ageng Tirtayasa, Indonesia

10.21831/inersia.v17i1.40570

Abstract

ABSTRACT

The high demand for electricity needs requires the availability of new generation sites. The new plant developed is a PLTU in Lontar. The condition of coal shelter as a research site dominated by silty clay and silty sand and located in the earthquake zoning is high that the planning of the coal shelter area must accordance with the feasibility of building establishment, it is necessary to analyze the potential liquefaction and improvement methods. Soil improvement efforts to reduce the potential for liquefaction include soil improvement with stone columns. The method of liquefaction analysis in this study uses the method developed by Idriss and Boulanger. The results of the analysis of the potential for liquefaction at BH-1 occurred at a depth of 3-16 m and at BH-3 the potential for liquefaction occurred at a depth of 4-24 m. Potential of the thickest layer for liquefaction is at BH-3 with a depth of 24 m. Improvement with a stone column can reduce the potential for liquefaction and can increase the value of the safety factor against the potential for liquefaction at the coal shelter location. Improvement analysis with a stone column using Plaxis software, the value of the safe factor after installing the stone column at BH-1 FS 2.89, at BH-3 FS became 2.65.

ABSTRAK

Banyaknya permintaan kebutuhan listrik yang tinggi diperlukan ketersediaan lokasi pembangkit baru. Pembangkit baru yang dikembangkan yaitu PLTU Batubara di Lontar. Kondisi coal shelter sebagai lokasi penelitian yang didominasi oleh lapisan tanah lempung kelanauan dan pasir kelanauan serta berada pada zonasi gempa cukup tinggi sehingga perencanaan area coal shelter harus memenuhi syarat kelayakan pendirian bangunan, maka perlu dilakukan analisis potensi likuefaksi serta metode perbaikannya. Upaya perbaikan tanah untuk mengurangi potensi likuefaksi yaitu perbaikan tanah dengan stone column (kolom batu). Metode analisis likuefaksi pada penelitian ini menggunakan metode yang dikembangkan oleh Idriss dan Boulanger. Hasil analisis potensi likuefaksi pada titik BH-1 terjadi di kedalaman 3-16 m dan pada titik BH-3 potensi likuefaksi terjadi pada kedalaman 4-24 m. Lapisan yang paling tebal mengalami potensi likuefaksi ada pada titik BH-3 dengan kedalaman 24 m. Perbaikan dengan stone column dapat mengurangi potensi likuefaksi dan mampu meningkatkan nilai faktor keamanan terhadap potensi likuefaksi di lokasi coal shelter. Analisis perbaikian dengan stone column menggunakan software Plaxis, nilai faktor aman setelah dipasang stone column pada titik BH-1 FS 2,89, pada titik BH-3 FS menjadi 2,65.

Keywords

Liquefaction; Soil improvement; Stone column

Full Text:

PDF

References

E. Soebowo, A. Tohari, and D. Sarah, “Potensi likuifaksi akibat gempabumi berdasarkan data CPT dan N-Spt di Daerah Patalan Bantul, Yogyakarta,” Ris. Geol. dan Pertamb., vol. 2, no. 2, pp. 85–97, 2009.

M. Otsubo, I. Towhata, T. Hayashida, B. Liu, and S. Goto, “Shaking table tests on liquefaction mitigation of embedded lifelines by backfilling with recycled materials,” Soils Found., vol. 56, no. 3, pp. 365–378, 2016, doi: 10.1016/j.sandf.2016.04.004.

S. Toprak and T. L. Holzer, “Liquefaction Potential Index: Field assessment,” J. Geotech. Geoenvironmental Eng., vol. 129, no. 4, pp. 315–322, 2003, doi: 10.1061/(asce)1090-0241(2003)129:4(315).

H. B. Seed and I. M. Idriss, “Simplified procedure for evaluating soil liquefaction potential,” J. Soil Mech. Found., vol. 97, no. 9, 1971, doi: https://doi.org/10.1061/JSFEAQ.0001662.

M. Mokhtari and B. Kalantar, “Soft soil stabilization using stone columns-a review,” Electron. J. Geotech. Eng., vol. 17, pp. 1459–1466, 2012.

T. Iwasaki, T. Arakawa, and K. I. Tokida, “Simplified procedures for assessing soil liquefaction during earthquakes,” Soil Dyn. Earthq. Eng., vol. 3, no. 1, pp. 49–58, 1984, doi: 10.1016/0261-7277(84)90027-5.

T. Iwasaki, K. Tokida, and F. Tatsuoka, “Soil liquefaction potential evaluation with use of the simplified procedure,” First Int. Conf. Recent Adv. Geotech. Earthq. Eng. Soil Dyn., pp. 209–214, 1981.

A. Jalil, T. F. Fathani, I. Satyarno, and W. Wilopo, “A study on the liquefaction potential in Banda Aceh city after the 2004 Sumatera earthquake,” Int. J. GEOMATE, vol. 18, no. 65, pp. 147–155, 2020, doi: 10.21660/2020.65.94557.

I. M. Idriss and R. W. Boulanger, “Soil liquefaction during earthquakes,” Earthq. Eng. Res. Inst., 2008.

M. A. Nisa, I. Satyarno, and H. C. Hardiyatmo, “Perancangan fondasi gedung Temporary Evacuation Shelter (TES) tsunami dan gempa,” INERSIA lNformasi dan Ekspose Has. Ris. Tek. SIpil dan Arsit., vol. 16, no. 2, pp. 117–129, 2020, doi: 10.21831/inersia.v16i2.36898.

T. L. Youd and I. M. Idriss, “Liquefaction resistance of soils: Summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils,” J. Geotech. Geoenvironmental Eng., vol. 127, no. 10, pp. 817–833, 2001.

FHWA, “Design and Construction Stone Columns Vol 1,” no. December 1983, 1983.

B. McCabe, J. McNeill, and J. Black, “Ground improvement using the vibro-stone column technique,” Jt. Meet. Eng. Irel. …, no. January 2015, pp. 1–12, 2007.

DOI: https://doi.org/10.21831/inersia.v17i1.40570