RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT.
KPP 22022015
Tipe Kelongsoran
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Tipe Kelongsoran (General)
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Tipe Kelongsoran (General)
Tipe Kelongsoran Pada Tambang Terbuka
A. Plane Failure
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
- One Plane and One Block
- Plane and Tension Crack
- Sliding Planes and Cross Joints
- Two Sliding Planes
- Sliding Plane with Several Blocks
- Wedge Failure
Types of Rock Slope Failure
A. Plane Failure
1. One Plane and One Block
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
A. Plane Failure
2. Plane and Tension Crack
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
A. Plane Failure
2. Plane and Tension Crack
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
A. Plane Failure
3. Sliding Planes and Cross Joints
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
A. Plane Failure
4. Two Sliding Planes
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
A. Plane Failure
5. Sliding Plane with Several Blocks
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
6. Wedge Failure
A. Plane Failure
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
6. Wedge Failure
A. Plane Failure
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
B. Rotational Failure
Particular Type of Failure and Illustrative Diagram :
- Rotational
- Rotational and Sliding Surface
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
B. Rotational Failure
1. Rotational
Types of Rock Slope Failure
B. Rotational Failure
1. Rotational
Types of Rock Slope Failure
B. Rotational Failure
1. Rotational and Sliding Surface
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
C. Toppling Failure
Illustrative Diagram :
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
C. Toppling Failure
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
C. Toppling Failure
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Types of Rock Slope Failure
C. Toppling Failure
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
kelongsoran lereng
Tanda awal
tambang
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Crack (rekahan)
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Scarps
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Adanya Rembesan Air Pada
Lereng
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Rembesan air pada kaki lereng
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Pelendutan (Bulging)
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Rayapan (Creeping)
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Pencegahan
Longsor
Upaya mengurangi laju pergerakan lereng
1. Menutup retakan pada atas tebing dengan
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
material impermeable (lempung).
2. Memperbaiki tata air terutama untuk
menangani adanya mata air/rembesan air
pada lereng atau pada saat curah hujan
yang tinggi pada waktu yang lama.
Upaya menambah kestabilan lereng
1. Perubahan geometri lereng
2. Perkuatan lereng( butress / counter weight, rock
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
bolt )
3. Pengurangan beban tekanan air tanah
(Dewatering hole)
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Istilah dalam
Geoteknik
Pit Slope
(lereng bukaan tambang)
crest
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Overall Slope
Toe Single slope
Lereng (slope) adalah bentuk permukaan bumi yang miring terhadap horizontal. Lereng
bukaan tambang terdiri dari :
Single slope, lereng tunggal yang terbentuk dari satu jenjang (bench) yang terdiri dari tinggi
lereng (sama dengan tinggi bench), sudut lereng, kaki lereng (Toe), dan siku lereng (Crest).
Inter-ramp slope, lereng yang terbentuk antar jalan tambang, dapat terbentuk dari
beberapa jenjang (benches).
Lereng keseluruhan (Overall Pit Slope), lereng yang terbentuk dari Crest teratas dan Toe
terbawah, dengan tinggi total lereng sama dengan kedalaman bukaan tambang.
Safety Factor
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Untuk menyatakan tingkat kemantapan suatu lereng
dikenal apa yang disebut dengan Faktor Keamanan.
FK merupakan perbandingan antara besarnya gaya
penahan dengan gaya penggerak longsoran
SF Overall slope > 1,5
SF Single slope > 1,3
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
SF ( 1.3 – 1.5 ) > Overall slope
Simple Slope
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Slope Deformation
Monitoring
Slope STABILITY Monitoring
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Asumsi penyederhanaan terhadap desain tambang
(pit slope), perlu dilakukan pemantauan terhadap
kinerja dinding lereng bukaan tambang
Alat/ sarana yang bertujuan untuk memahami
perilaku massa batuan/ mendeteksi adanya kondisi
lereng yang tidak stabil
Sasaran utama
Proteksi terhadap pekerja
Peralatan
Kelangsungan produksi
MONITORING PERGERAKAN LERENG
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
MONITORING
PERGERAKAN
LERENG
NO NO
Medium
Low Velocity ? Hi Velocity ?
Velocity ?
YES
YES
Inform critical
Design & Increase visual inspection freq (critical hazard to related
Rekomendasi
area) dept.
Analisa Stabilitas NO
Lereng
Need Emergency
Redesign? &
Remedial
Preparedness &
Work ? Response
YES
Typical displacement time behaviour for pit slope failure (Broadbent & Zavodni, 1981)
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Instrumen Pemantauan Pergerakan Lereng
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Slope Stability Radar
Robotic Total Station
Robotic Total Station Manual Extensometer
Contoh Hasil Pengukuran Pergerakan Lereng Terhadap Waktu
(Albert Cabrejo, GroundProbe, Australia, 2012)
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Regressive
Progressive
linear
Contoh Hasil Pengukuran Pergerakan Lereng Terhadap Waktu
Pada Batuan Brittle (Albert Cabrejo, GroundProbe, Australia, 2012)
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Response Time
digunakan untuk
proses evakuasi
pekerja serta alat
Response Time
kerja
Progressive
linear
RESI YOGIE BASKORO – BASIC GEOTECHNIC DAY 2 – PT. KPP 22022015
Sudahkah anda “aware”
mengenai potensi longsor di
lereng tambang anda??
