Analisis Kualitas dan Perkuatan Terowongan Eksplorasi Uranium Eko Remaja Kalan, Kalimantan Barat menggunakan Metode RMR (Rock Mass Rating)
DOI: http://dx.doi.org/10.55981/eksplorium.2020.5859
Abstract
ABSTRAK Terowongan Eksplorasi Uranium Eko Remaja Kalan (TEURK) di Kalimantan Barat yang dibangun pada tahun 1980 merupakan salah satu sarana penelitian cebakan uranium di Indonesia. Terowongan ini menembus Bukit Eko Remaja sepanjang 618 m, mulai dari pintu Remaja hingga TRK-7. Mineralisasi uranium di lokasi ini dikontrol oleh urat-urat tak beraturan (stockwork) yang sangat rapat pada batuan metalanau dan metapelit. Tingginya kerapatan struktur geologi tersebut membentuk beberapa zona lemah di dalam terowongan. Zona lemah tersebut berpotensi menyebabkan terjadinya longsor batu dan tanah. Penyangga sementara terbuat dari tiang-tiang kayu dipasang di zona tersebut untuk perkuatan terowongan. Saat ini tiang kayu tersebut tidak lagi mampu menyangga terowongan sehingga sering terjadi longsor batu dan tanah di dalam terowongan. Penelitian ini bertujuan untuk mengetahui kualitas massa batuan aktual dan menentukan jenis perkuatan yang sesuai agar terowongan tetap aman. Survei palu Schmidt dan scanline pada zona tak berpenyangga (kedalaman 50–297 m dan 355–538 m) dilakukan untuk mengambil data parameter klasifikasi Rock Mass Rating (RMR). Hasil pengukuran menunjukkan bahwa massa batuan TEURK di kedalaman tersebut memiliki nilai RMR 52-71 (sedang–baik). Perkuatan yang direkomendasikan adalah pemasangan baut batu dan beton semprot konvensional.
ABSTRACT Tunnel for Exploration of Uranium Eko Remaja Kalan (TEURK) in West Kalimantan, built-in 1980, is one of the uranium deposit research facilities in Indonesia. The tunnel penetrated Eko Remaja Hill along 618 m, from Remaja to TRK-7 access. Uranium mineralization in this area controlled by dense stockwork veins on metasilt and metasandstone rocks. The high-dense geological structures create some weak zones in the tunnel. These zones are potentially causing rocks and soil slides. Temporary supports made of wood-piles were installed in these zones to support the tunnel. Currently, these piles are not capable at the tunnel, so that rocks and soil slides occurred inside the tunnel. The research aimed to determine the quality of actual rock mass and determine the appropriate type of reinforcement to keep the tunnel safe. Schmidt hammer and scanline surveys on the unsupported zone (50–297 m and 355–538 m depth) carried out to collect the classification parameter data of Rock Mass Rating (RMR). The measurement result shows that the rock mass of TEURK on the depth has an RMR value of 52–71 (fair-good). Reinforcement recommendations for the tunnel are rock bolts and conventional shotcretes installation.
Keywords
Full Text:
PDF (Bahasa Indonesia)References
[1] BAKOSURTANAL, “Peta Rupabumi Lembar Nanga Pinoh, Kalimantan,” 2004.
[2] H. Syaeful, Suharji, dan A. Sumaryanto, “Pemodelan Geologi dan Estimasi Sumberdaya Uranium di Sektor Lemajung, Kalan, Kalimantan Barat,” Pros. Semin. Nas. Teknol. Energi Nukl., pp. 329–342, 2014.
[3] A. Zaenal, “Beton Cetak Bertulang sebagai Alternatif Pengganti Kayu Penyangga di Terowongan Eksplorasi U Eko Remaja Kal-Bar,” dalam Prosiding Seminar Geologi Nuklir dan Sumberdaya Tambang, 2006.
[4] H. S. Karyono, “Analisis Kontrol Tektonik pada Vein Mineralisasi di Bukit Eko, Kalan, Kalimantan Barat,” dalam Prosiding Pertemuan Ilmiah Tahunan ke-2 IAGI, 1991, pp. 115–128.
[5] Amiruddin dan D. S. Trail, “Peta Geologi Lembar Nanga Pinoh Kalimantan Skala 1:250.000,” Bandung, 1993.
[6] S. Tjokrokardono, B. Soetopo, L. Subiantoro, dan K. S. Widana, “Geologi dan Mineralisasi Uranium Kalan, Kalimantan Barat,” dalam Kumpulan Laporan Hasil Penelitian Tahun 2005, Jakarta: BATAN, 2005, pp. 27–52.
[7] D. Kamajati, H. Syaeful, dan M. Berliana Garwan, “Evaluasi Massa Batuan Terowongan Eksplorasi Uranium Eko-Remaja, Kalan, Kalimantan Barat,” Eksplorium, vol. 37, no. 2, pp. 89–100, 2016.
[8] S. Tjokrokardono, D. Soetarno, M. S. Sapardi, L. Subiantoro, dan R. Witjahyati, “Studi Geologi Regional dan Mineralisasi Uranium di Pegunungan Schwanner Kalimantan Barat dan Tengah,” dalam Prosiding Seminar Geologi Nuklir dan Sumberdaya Tambang, 2004, pp. 64–84.
[9] H. S. Karyono dan M. Ruhland, “Use of Multiscalar Processing of Remotely Sensed Data in Kalan Fracturation Networks West Kalimantan, Indonesie for Future Mineralization Research,” ISPRS J. Photogrametry Remote Sens., vol. 45, pp. 428–441, 1990.
[10] A. G. Muhammad dan F. D. Indrastomo, “Validitas dan Reliabilitas Data Estimasi Kadar Uranium Sektor Lembah Hitam, Kalan, Kalimantan Barat,” Eksplorium, vol. 40, no. 2, pp. 75–88, 2019, doi: 10.17146/eksplorium. 2019.40.2.5672.
[11] Z. T. Bieniawski, Engineering Rock Mass Classification: A Complete Manual for Engineers and Geologists in Mining, Civil, and Petroleum Engineering. 1989.
[12] F. Ferrari, T. Apuani, dan G. Giani, “Rock Mass Rating Spatial Estimation by Geostatistical Analysis,” Int. J. Rock Mech. Min. Sci., vol. 70, pp. 162–176, 2014.
[13] M. Akin, “Slope Stability Problems and Back Analysis in Heavily Jointed Rock Mass: A Case Study from Manisa, Turkey,” Rock Mech. Rock Eng., vol. 46, pp. 359–371, 2013.
[14] Purwanto, et al., “Fundamental Study on Support Systemat Cibaliung Underground Gold Mine, Indonesia,” Procedia Earth Planet. Sci., vol. 6, pp. 419–425, 2013.
[15] V. M. Khatik dan A. K. Nandi, “A generic method for rock mass classification,” Rock Mech. Geotech. Eng., vol. 10, no. 1, pp. 102–116, 2018.
[16] A. Lateef, “Most used rock mass classifications for underground opening,” Am. J. Eng. Appl. Sci., pp. 403–411, May 2010.
[17] Z. T. Bieniawski, “Classification of rock masses for engineering: The RMR system and future trends, comprehensive rock engineering,” vol. 3, pp. 553–574, 1993.
[18] S. Muntazir Abbas dan H. Konietzky, “Rock mass classification systems,” Introd. to Geomech., pp. 1–48, 2017.
[19] M. Mohammadi dan M. Farouq, “Modification of rock mass rating system : Interbedding of strong and weak rock layers,” J. Rock Mech. Geotech. Eng., vol. 9, no. 6, pp. 1165–1170, 2017.
[20] N. Bilgin, H. Copur, dan C. Balci, “Use of Schmidt Hammer with Special Reference to Strength Reduction Factor Related to Cleat Presence in A Coal Mine,” Int. J. Rock Mech. Min. Sci., vol. 84, pp. 25–33, 2016.
[21] B. F. Ogunbayo, C. O. Aigbavboa, dan O. I. Akinradewo, “Analysis of Compressive Strength of Existing Higher Educational Institutions (HEI) Concrete Column using a Schmidt Rebound Hammer,” J. Phys. Conf. Ser., vol. 1378, no. 3, 2019.
[22] A. Brencich, G. Cassini, D. Pera, dan G. Riotto, “Calibration and Reliability of the Rebound (Schmidt) Hammer Test,” Civ. Eng. Archit., vol. 1, no. 3, pp. 66–78, 2013.
[23] I. Yilmaz dan H. Sendir, “Correlation of Schmidt hardness with unconfined compressive strength and Young’s modulus in gypsum from Sivas (Turkey),” Eng. Geol., vol. 66, no. 3, pp. 211–219, 2002.
[24] H. I. Chamine, M. J. Afonso, L. Ramos, dan R. Pinheiro, “Scanline Sampling Techniques for Rock Engineering Surveys: Insights from Intrinsic Geologic Variability and Uncertainty,” Eng. Geol. Soc. Territ., vol. 6, pp. 357–361, 2015.
[25] G. A. J. Kartini, I. Gumilar, B. Brahmantyo, B. Bramanto, dan N. Haerani, “Hasil Pengukuran Terrestrial Laser Scanner untuk Deteksi Rekahan dalam Kaitannya dengan Analisis Struktur Geologi (Studi Kasus: Tebing Citatah 125, Jawa Barat),” J. Lingkung. dan Bencana Geol., vol. 9, pp. 107–117, 2018.
[26] S. K. Haldar, Mineral Exploration: Principles and Applications, 2nd ed. Elsevier Ltd, 2018.
[27] L. Zhang, “Determination and applications of rock quality designation (RQD),” J. Rock Mech. Geotech. Eng., vol. 8, no. 3, pp. 389–397, 2016.
[28] S. D. Priest dan J. A. Hudson, “Discontinuity spacings in rock,” Int. J. Rock Mech. Min. Sci., vol. 13, pp. 135–148, 1976.
[29] Z. T. Bieniawski, “The geomechanics classification in rock engineering applications,” dalam Proceedings of the 4th Congress of the International Society for Rock Mechanics, 1979, pp. 41–48.
[30] S. Dochez et al., “Influence of Water on Rock Discontinuities and Stability of Rock Mass,” Procedia Earth Planet. Sci., vol. 7, pp. 219–222, 2013.
[31] B. Celada, I. Tardáguila, P. Varona, A. Rodríguez, dan Z. T. Bieniawski, “Innovating Tunnel Design by an Improved Experience-based RMR System,” Proc. World Tunn. Congr. 2014 – Tunnels a better Life, pp. 1–9, 2014.
[32] Z. T. Bieniawski, Rock mechanics design in mining and tunnelling. Rotterdam, 1984.
[33] A. R. Lowson dan Z. T. Bieniawski, “Critical Assessment of RMR-based Tunnel Design Practices: A Practical Engineer’s Approach,” Rapid Excav. Tunneling Conf., June, 2013.
[34] B. Singh dan R. K. Goel, Engineering Rock Mass Classification: Tunneling, Foundations, and Landslides, 1st ed. Butterworth-Heinemann, 2011.
[35] H. Rehman, A. M. Naji, J. J. Kim, dan H. K. Yoo, “Empirical Evaluation of Rock Mass Rating and Tunneling Quality Index System for Tunnel Support Design,” Appl. Sci., vol. 8, 2018.
Refbacks
Copyright EKSPLORIUM: Buletin Pusat Pengembangan Bahan Galian Nuklir (e-ISSN 2503-426x p-ISSN 0854-1418)
National Research and Innovation Agency (BRIN), KA. B.J. Habibie, Jl. M.H. Thamrin No.8, Jakarta, 10340, Indonesia.