DAFTAR ISI
LEMBAR PENGESAHAN ............................................................................. i KATA PENGANTAR .................................................................................... ii ABSTRAK....................................................................................................... v ABSTRACT ..................................................................................................... vi DAFTAR ISI .................................................................................................. vii DAFTAR GAMBAR ..................................................................................... ix DAFTAR TABEL .......................................................................................... xi DAFTAR LAMPIRAN .................................................................................. xii BAB I PENDAHULUAN ................................................................................ 1 1.1 Latar Belakang ................................................................................ 1 1.2 Identifikasi Masalah ........................................................................ 2 1.3 Maksud dan Tujuan Penelitian ......................................................... 2 1.4 Kegunaan Penelitian ........................................................................ 3 1.5 Pelaksanaan Penelitian .................................................................... 3 1.6 Lokasi dan Waktu Penelitian ........................................................... 4 BAB II TINJAUAN PUSTAKA ..................................................................... 7 2.1 Kondisi Geologi Daerah Penelitian .................................................. 7 2.2 Teori Dasar ..................................................................................... 10 2.2.1 Geologi Bawah Permukaan .................................................... 10 2.2.2 Klasifikasi Massa Batuan ....................................................... 10 2.2.3 Rock Mass Rating (RMR) ...................................................... 11 2.2.3.1 Kekuatan Batuan (Rock Strength) ............................... 11 2.2.3.2 Rock Quality Designation (RQD) ............................... 15 2.2.3.3 Jarak Diskontinuitas (Spacing of Discontinuities) ....... 17 2.2.3.4 Kondisi Diskontinuitas (Condition of Discontinuities) 18 2.2.3.5 Kondisi Airtanah (Groundwater Condition) ............... 18 2.2.3.6 Orientasi Diskontinuitas ............................................. 19 2.2.4 Penentuan Kelas RMR ........................................................... 19 2.2.5 Petrografi ............................................................................... 21 BAB III METODE PENELITIAN ................................................................. 24 3.1 Objek Penelitian .............................................................................. 24 3.2 Peralatan Lapangan ......................................................................... 24 3.3 Langkah-Langkah Penelitian ........................................................... 26 3.3.1 Tahap Persiapan ..................................................................... 26 3.3.2 Tahap Pekerjaan Lapangan dan Studio ................................... 26 3.3.3 Tahap Pengolahan Data dan Pembahasan ............................... 27 3.3.4 Tahap Penyusunan Laporan ................................................... 28 BAB IV HASIL PENELITIAN DAN PEMBAHASAN ................................. 30 4.1 Hasil Penelitian ............................................................................... 30 4.1.1 Geologi Daerah Penelitian ...................................................... 30 4.1.2 Hasil Penyelidikan Geologi Bor Penelitian ............................. 32 4.1.2.1 Bor CC 25 (Kedalaman 80 m – EOH) ........................ 33
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4.1.2.2 Bor CC 19 (Kedalaman 74,1 m – EOH) ..................... 36 4.1.2.3 Bor CC 19A (Kedalaman 131,6 m – EOH)................. 37 4.1.2.4 Bor CC 20 (Kedalaman 67,1 m – EOH) ..................... 39 4.1.2.5 Bor CC 24A (Kedalaman 122,25 m – EOH) ............... 42 4.1.2.6 Bor CC 28 (Kedalaman 186,3 m – EOH) ................... 45 4.1.3 Hasil Penyelidikan Geoteknik Bor Penelitian ......................... 47 4.1.3.1 Kekuatan Batuan ........................................................ 47 4.1.3.2 Rock Quality Designation (RQD) ............................... 48 4.1.3.3 Jarak Diskontinuitas ................................................... 49 4.1.3.4 Kondisi Diskontinuitas ............................................... 51 4.1.3.5 Kelas Massa Batuan (RMR) ....................................... 51 4.1.4 Hasil Analisis Petrografi ........................................................ 52 4.2 Pembahasan .................................................................................... 54 4.2.1 Kondisi Geologi Bawah Permukaan Daerah Penelitian ........... 55 4.2.2 Kontribusi Uniaxial Compressive Strenght (UCS) Terhadap Nilai Massa Batuan (RMR) ................................................... 58 4.2.3 Kontribusi Kualitas Batuan (RQD) Terhadap Nilai Massa Batuan (RMR) ....................................................................... 65 4.2.4 Kajian UCS Berdasarkan Aspek Petrografi ............................ 72 4.2.5 Pengaruh Aspek Struktur Geologi Terhadap Parameter RQD . 73 BAB V KESIMPULAN DAN SARAN ........................................................... 75 5.1 Kesimpulan ..................................................................................... 75 5.2 Saran ............................................................................................... 76 DAFTAR PUSTAKA .................................................................................... 77
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DAFTAR GAMBAR
Gambar 1.1 Gambar 1.2 Gambar 1.3 Gambar 2.1 Gambar 2.2 Gambar 2.3
Gambar 2.4 Gambar 2.5 Gambar 2.6 Gambar 2.7 Gambar 3.1 Gambar 3.2 Gambar 4.1 Gambar 4.2 Gambar 4.3 Gambar 4.4 Gambar 4.5 Gambar 4.6 Gambar 4.7 Gambar 4.8 Gambar 4.9 Gambar 4.10 Gambar 4.11 Gambar 4.12 Gambar 4.13 Gambar 4.14 Gambar 4.14 Gambar 4.15 Gambar 4.16 Gambar 4.17
Peta Lokasi Penelitian (Sumber: UBPE Pongkor PT. Antam (Persero) Tbk, 2011) .................................................................... 4 Peta IUP UBPE Pongkor PT. Antam (Persero) Tbk (Sumber: UBPE Pongkor PT. Antam (Persero) Tbk, 2011) ......................... 5 Peta Situasi Lokasi Penelitian (Sumber: Unit Geomin Pongkor PT. Antam (Persero) Tbk, 2012)......................................................... 6 Peta Geologi Daerah Pongkor dan Sekitarnya (Sunardi dkk, 2001) .................................................................................................... 9 Cara Pengukuran Point Load Test, a. Diametrikal, b. Axial, c. Blok, d. Irregular (ISRM, 1985) ................................................. 12 Ilustrasi pecah conto batuan Point Load Test (a) tes diametrikal valid, (b) tes axial valid, (c) tes blok valid, (d) tes conto gagal, (e) tes axial gagal (ISRM, 1985)...................................................... 12 Perhitungan RQD (After Deere, 1989; dalam Hoek 1995) .......... 16 Hubungan antara RQD dan Frekuensi Diskontinuitas (after Priest & Hudson, 1976; dalam Zhang, 2006)........................................ 17 Klasifikasi Tuf (Schmid, 1981; dalam Gillespic and Styles, 1999) .................................................................................................. 21 Klasifikasi Mineral Alterasi (Corbett & Leach, 1996) ................ 23 Alat Point Load Test .................................................................. 27 Bagan Alir Penelitian ................................................................. 29 Litologi Lava Andesitik pada (a) Stasiun cc2.8, (b) Stasiun 2cc1.3 ...................................................................... 30 Litologi Tuf Lapili pada (a) Stasiun 2cc2.1, (b) Stasiun cc2 ....... 31 Penampang Bor Bawah Permukaan............................................ 32 Penampang Vertikal Bor CC 25 ................................................. 35 Penampang Vertikal Bor CC 19 ................................................. 37 Penampang Vertikal Bor CC 19A .............................................. 39 Penampang Vertikal Bor CC 20 ................................................. 41 Penampang Vertikal Bor CC 24A .............................................. 43 Penampang Vertikal Bor CC 28 ................................................. 46 Grafik Distribusi Kekuatan Batuan Tiap Bor Penelitian ............. 48 Grafik Distribusi RQD Tiap Bor Penelitian ................................ 49 Grafik Distribusi Jarak Diskontinuitas Tiap Bor Penelitian ........ 50 Grafik Distribusi RMR Tiap Bor Penelitian ............................... 52 Korelasi Penampang Geologi Bawah Permukaan Daerah Penelitian .................................................................................................. 56 Korelasi Penampang Geologi Bawah Permukaan DaerahPenelitian .................................................................................................. 56 Kemenerusan Vein dan Zona Lemah Daerah Penelitian ............. 57 Zonazi RMR Daerah Penelitian.................................................. 58 Grafik RMR dan UCS Berdasarkan Kedalaman Pemboran ........ 59
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Gambar 4.18 UCS dan Litologi Daerah Penelitian .......................................... 63 Gambar 4.19 UCS dan RMR Daerah Penelitian .............................................. 64 Gambar 4.20 Grafik RMR dan RQD Berdasarkan Kedalaman Pemboran ........ 66 Gambar 4.21 RMR dan RQD Daerah Penelitian .............................................. 70 Gambar 4.22 Nilai RQD dan Kemenerusan Vein dan Zona Lemah Bor Penelitian .................................................................................................. 74
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DAFTAR TABEL
Tabel 2.1 Tabel 2.2 Tabel 2.3 Tabel 2.4 Tabel 2.5 Tabel 2.6 Tabel 2.7 Tabel 2.8 Tabel 3.1 Tabel 4.1 Tabel 4.2 Tabel 4.3 Tabel 4.4 Tabel 4.5 Tabel 4.6 Tabel 4.7 Tabel 4.8 Tabel 4.9 Tabel 4.10 Tabel 4.11 Tabel 4.12 Tabel 4.13 Tabel 4.14 Tabel 4.15 Tabel 4.16 Tabel 4.17
Klasifikasi Kekuatan Batuan (After Bieniawski, 1989) .............. 14 Kisaran UCS pada Batuan Utuh (AASHTO, 1989; dalam Zhang, 2006) ........................................................................................ 15 Rock Quality Designation (After Bieniawski, 1989) .................. 16 Klasifikasi Jarak Diskontinuitas (After Bieniawski, 1989) ......... 17 Kondisi Diskontinuitas (After Bieniawski, 1989) ...................... 18 Kondisi Airtanah (After Bieniawski, 1989) ............................... 19 Rock Mass Rating System (After Bieniawski, 1989) .................. 20 Klasifikasi Batuan Beku (Travis, 1955)..................................... 22 Koordinat Titik Bor Penelitian .................................................. 24 Kisaran Kekuatan Batuan di Daerah Penelitian ......................... 48 RMR dan UCS pada Bor CC 25 ................................................ 60 RMR dan UCS pada Bor CC 19 ................................................ 61 RMR dan UCS pada Bor CC 19A ............................................. 61 RMR dan UCS pada Bor CC 20 ................................................ 62 RMR dan UCS pada Bor CC 24A ............................................. 62 RMR dan UCS pada Bor CC 28 ................................................ 63 Persentase Kontribusi UCS Terhadap RMR Daerah Penelitian .. 63 RMR dan RQD pada Bor CC 25 ............................................... 66 RMR dan RQD pada Bor CC 19 ............................................... 66 RMR dan RQD pada Bor CC 19A ............................................ 67 RMR dan RQD pada Bor CC 20 ............................................... 68 RMR dan RQD pada Bor CC 24A ............................................ 68 RMR dan RQD pada Bor CC 28 ............................................... 69 Persentase Kontribusi RQD Terhadap RMR Daerah Penelitian . 69 Matriks Kesimpulan RMR, UCS, dan RQD .............................. 71 Perbandingan Komposisi Mineral Penyusun Batuan ................. 71
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DAFTAR LAMPIRAN
Lampiran Peta 1 (Peta Kerangka Geologi)…………….……….………………. Lampiran Peta 2 (Peta Penyebaran Struktur Geologi)…………………………. Lampiran Peta 3 (Peta Geologi)…………..…………….……….………………. Lampiran Zonasi RMR………………………………………………………….. Lampiran Log Bor……………………………………………………………….. Lampiran Analisis Petrografi……………………………………………………. Lampiran Jurnal Pemetaan Geologi…………………………………………….. Lampiran Uji Point Load…………………………………………………………
