laporan geologi daerah poso

LAPORAN PENUNJANG

VOLUME IIDesign Rinci Bendungan Poso-1, Kabupaten Poso

GEOLOGI DAN GEOLOGI TEKNIK

DAFTAR ISI

BAB 1 Pendahuluan

1.1 Latar Belakang.......................................................................................................................1-1

1.2 Maksud dan Tujuan................................................................................................................1-2

1.3 Lokasi Penyelidikan dan Kesampaian Daerah.......................................................................1-2

1.4 Lingkup Pekerjaan..................................................................................................................1-3

1.5 Kuantitas dan Jenis Pekerjaan................................................................................................1-4

BAB 2 Geolohi Regional

2.1 Fisiografi Regional.................................................................................................................2-1

2.2 Stratigrafi Regional................................................................................................................2-2

2.2.1 Stratigrafi Menurut T.O. Simandjuntak, dkk.............................................................2-2

2.2.2 Stratigrafi Regional Menurut Michel Villeneuve, dkk..............................................2-4

2.3 Struktur dan Tektonik Regional.............................................................................................2-7

2.4 Kegempaan.............................................................................................................................2-8

BAB 3 Investigasi Geologi Teknik

3.1 Pemetaan Geologi...................................................................................................................3-1

3.2 Pemboran Inti..........................................................................................................................3-1

3.3 Pengujian Permeabilitas..........................................................................................................3-3

a. Water Pressure Test..........................................................................................................3-3

b. Falling Head Method........................................................................................................3-5

3.4 Sumur Uji................................................................................................................................3-6

3.5 Pengujian Laboratorium.........................................................................................................3-7

3.6 Pengujian Seismik..................................................................................................................3-8

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LAPORAN PENUNJANG



1. Pengujian Seismik Down Hole........................................................................................3-8

2. Pengujian Seismik Refraksi.............................................................................................3-9

BAB 4 Geologi Teknik

4.1 Geologi Daerah Bendungan PLTA Poso-1.............................................................................4-1

4.1.1 Geomorfologi.............................................................................................................4-1

4.1.2 Stratigrafi...................................................................................................................4-3

4.1.3 Struktur Geologi........................................................................................................4-5

4.2 Geoteknik Lokasi Bendungan.................................................................................................4-7

4.2.1 Pemboran Inti............................................................................................................4-7

4.2.2 Permeabilitas As Bendungan.....................................................................................4-12

4.2.3 Galian Pondasi...........................................................................................................4-12

4.2.4 Daya Dukung Pondasi...............................................................................................4-13

4.2.5 Hasil Seismik Down hole dan Refraksi....................................................................4-14

4.2.6 Hasil Pengujian Laboratorium...................................................................................4-17

4.2.7 Perbaikan Pondasi......................................................................................................4-17

4.3 Geologi Daerah Genangan......................................................................................................4-19

4.3.1 Stratigrafi...................................................................................................................4-19

4.3.2 Stratigrafi...................................................................................................................4-19

4.3.3 Kebocoran Waduk.....................................................................................................4-20

BAB 5 Bahaya Geologio (Geologi Hazard)

5.1 Umum.....................................................................................................................................5-1

5.2 Kondisi Geologi Daerah Penyelidikan...................................................................................5-1

5.3 Lokasi Potensi Longsor dan Longsor.....................................................................................5-1

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LAPORAN PENUNJANG



5.4 Penyebab Terjadinya Gerakan Tanah.....................................................................................5-3

5.5 Penanggulangan...................................................................................................................... 5-5

BAB 6 Material Konstruksi

6.1 Umum.....................................................................................................................................6-1

6.2 Quarry Meko...........................................................................................................................6-2

6.3 Quarry Puna............................................................................................................................6-2

6.4 Quarry Pettirodongi................................................................................................................6-3

6.5 Quarry Pettirodongi................................................................................................................6-3

6.6 Ketersediaan dan Kebutuhan Material Konstruksi.................................................................6-3

6.7 Pengujian Laboratorium.........................................................................................................6-4

BAB 7 Kesimpulan Dan Saran

7.1 Kesimpulan.............................................................................................................................7-1

7.2 Saran.......................................................................................................................................7-1

Daftar Gambar

Gambar 1.1 Peta Lokasi Rencana Bendungan Poso-1....................................................................1-3

Gambar 2.1 Sketsa Peta Geologi Sulawesi Tengah (Van bemmelen, 1949)...................................2-1

Gambar 2.2 Peta Geologi Lembar Poso, Sulawesi”, 1997 dengan skala 1:250.000.......................2-8

Gambar 2.3 Peta Geologi Sulawesi Bagian Tengah (Michel Villeneuve, dkk., 2001....................2-9

Gambar 2.4 Susunan Stratigrafi Menurut Michel Villeneuve, dkk.................................................2-10

Gambar 2.5 Peta Zona Gempa Tahun 2010, Periode Gempa (T) 100 tahun...................................2-12

Gambar 2.6 Peta Zona Gempa Tahun 2010, Periode Gempa (T) 5000 tahun.................................2-12

Gambar 2.7 Nilai Percepatan Gempa Puncak 50 tahun, 100 tahun, 200 tahun, 500 tahun.............2-13

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Gambar 2.8 Nilai Percepatan Gempa Puncak 500 tahun, 1000 tahun, 2500 tahun.........................2-13

Gambar 2.9 Peta Sebaran Gempa Bumi Daerah Poso dan Sekitarnya............................................2-15

Gambar 3.1 Peta Sebaran Titik Bor di Area Bendungan PLTA Poso-1.........................................3-2

Gambar 3.2 Peta Pelaksanaan Seismic Downhole da refraksi di Bendungan PLTA Poso-1..........3-10

Gambar 4.1 Peta Geologi Daerah Bendungan.................................................................................4-7

Gambar 4.2 Penampang Geologi AS Bendungan...........................................................................4-13

Gambar 4.3 Penampang Permeability dan Lugeon.........................................................................4-14

Gambar 4.4 Grafik Kolerasi Empirik N (SPT) Dengan Daya Dukung Tanah/Berbutir halus dan

Campuran....................................................................................................................4-15

Gambar 4.5 Grafik Kolerasi Empirik N (SPT) dengan Daya Dukung Tanah/Berbutir Kasar dan

Campuran....................................................................................................................4-16

Gambar 4.6a Perbandingan Profil Geologi Hasil Log bore dengan Nilai Velocity Hasil Seismik..4-19

Gambar 4.6b Perbandingan Profil Geologi Hasil Log bore dengan Nilai Velocity Hasil Seismik..4-20

Gambar 4,6c Perbandingan Profil Geologi Hasil Log bore dengan Nilai Velocity Hasil Seismik..4-21

Gambar 4.6d Perbandingan Profil Geologi Hasil Log bore dengan Nilai Velocity Hasil Seismik..4-22

Gambar 4.7 Dena Titik Grouting Pondasi Bendungan....................................................................4-27

Gambar 4.8 Peta Genangan PLTA Poso-1 (2X30 MW Nett) dan Regulating DAM......................4-28

Daftar Tabel

Tabel 1.1 Kuantitas dan Jenis Pekerjaan........................................................................................1-4

Tabel 2.1 Stratigafi Antar Informasi Bantuan Lembar Poso Menurut Simandjuntak, dkk............2-8

Tabel 3.1 Lokasi Titik Pemboran Inti Bendungan Poso-1.............................................................3-3

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Tabel 3.2 Condition Of Rock Mass Discontinuities Associated With Different Lugeon Value....3-6

Tabel 3.3 Koordinat Lokasi Sumur Uji..........................................................................................3-7

Tabel 3.4 Koordinat Pengujian Seismik Downhole.......................................................................3-9

Tabel 3.5 Line Pengujian Seismik Refraksi di Lokasi Bendungan PLTA Poso-1..........................3-9

Tabel 4.1 Prediksi Zona Retakan atau Sesar dari Posisi Zona Low Velocity................................4-8

Tabel 4.2 Ringkasan Hasil Pemboran Geotenik di Lokasi Bendungan..........................................4-8

Tabel 4.3 Pengklasifikasian Jenis Tanah Berdasarkan Nilai Shear Wave Velocity.......................4-17

Tabel 4.4 Pengklasifikasian Jenis Tanah Berdasarkan Nilai Shear Wave Velocity.......................4-18

Tabel 4.5 Posisi Velocity Rendah di Line Seimic..........................................................................4-18

Tabel 4.6 Ringkasan Hasil Pengujian Laboratorium......................................................................4-23

Daftar Grafik

Grafik 2.1 Diagram Nilai Percepatan Gempa Puncak 5000 Tahun................................................2-14

Daftar Lampiran

Lampiran 1 Log Pemboran Inti

Lampiran 2 Perhitungan Permeabilitas

Lampiran 3 Foto-foto Drill Log

Lampiran 4 Foto-foto Tes Pit dan Trench Cut Lokasi DAM PLTA Poso-1

Lampiran 5 Foto-foto Kenampakan Morfologi

Lampiran 6 Foto-foto Singkapan Pemetaan Geologi

Lampiran 7 Foto-foto Struktur Geologi Lokasi

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LAPORAN PENUNJANG



Lampiran 8 Foto-foto Area Genangan DAM PLTA Poso-1

Lampiran 9 Foto-foto Bahaya Geologi (Geologi Hazard)

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laporan geologi daerah poso

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