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Ferra Fahraini
Jurusan Teknik Tambang Fakultas Teknik Universitas Bangka Belitung

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Penilaian Tingkat Kestabilan Lereng Batuan Granit Menggunakan Metode Slope Mass Rating (SMR) dan Analisis Kinematika di PT Mandiri Karya Makmur Mirsandi Mirsandi; Irvani Irvani; Ferra Fahraini
MINERAL Vol 2 No 2 (2017): MINERAL
Publisher : Jurusan Teknik Pertambangan Universitas Bangka Belitung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (909.188 KB) | DOI: 10.33019/mineral.v2i2.1563

Abstract

PT Mandiri Karya Makmur (MKM) was a private company that mine granite rock. Level in mine site was almost steep so that it had the possibility to failure. The study was conducted to assess the stability of rock slope that may endanger the safety of workers. This study to determine the quality of rock mass of slope based on the value of SMR (Slope Mass Rating) and kinematics analysis. The data used included UCS, RQD, Space of discontinuity, Discontinuity conditions, Groundwater conditions and Discontinuity orientation data. Slopes data were divided into 4 scanline based on the direction changing of the slope. To determine the type of failure using kinematics analysis of Dips program and Schmidt Net.The analysis results revealed that the quality of rock mass for scanline II was very good or very stable based on the SMR value. While on the rock mass quality of scanline I, III and IV were good with the stability of the slope was in a stable condition. The possibility of a failure in scanline I, III and IV were only several blocks. There were two blocks that has possibility to failure was on scanline III and IV. Estimation direction of slope failure on scanline III and IV respectively were N 1350 and N 1850 E. The supporting of slope instability can be done by scaling or cutting blocks that have potential to failure.
Analisa Kestabilan Lereng Menggunakan Metode Fellenius Secara Manual dan Software Slide Rocscience 6.0 (Studi Kasus : TB 1.42 Pemali PT Timah (Persero) Tbk Damos Tiambunan; Irvani Irvani; Ferra Fahraini
MINERAL Vol 3 No 1 (2018): MINERAL
Publisher : Jurusan Teknik Pertambangan Universitas Bangka Belitung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (703.043 KB) | DOI: 10.33019/mineral.v3i1.1575

Abstract

A hill slope is a part of a mining, especially mining by Open Pit Method. The TB 1.42 Pemali PT Timah (Persero)Tbk, which is often referred as the TB 1.42 applies the open it method in its mining, hence the condition of the hill slope greatly influences the mining Safety because hill slope instability can cause avalance. Hance, the hill slope stability has to be calculated.The calculation is performed to get the value of the safety factor (FK) and to understand the slope’s condition. This calculation can be done using yheFelleniusMethod, either manually or using,SoftwareSlideRocscience 6.0. The FelleniusMethod requires the shear strength parameter in the calculation, therefore a laboratory testing is performed using direct shear test ASTM D-3064-04. This test generates the value of cohesion (c),the angle of internal friction (ɸ) and the soil density (γ) of a soil sample taken from the field.Basedon the research the front south slope TB 1.42 Pemali have sandy loam lithology (Slope LT01), clay (Slope LT02 dan LT03), and gravelly clay (slope LT04). Based on the Fellenius Method, the value of FK for the slope is affected by the slope’s angle and shear strength parameter ( c and ɸ). The analysis conducted in this study showed that of the four slopes that are observed, there are two unstable slopes, which are slope LT02 with FK amounted to 0,809 (manual) and 0,877 (slide), which is unstable ; and the slope LT03 with FK amounted to 1,056 (manual) and 1,070 (slide), which is in critical condition. In order to solve the instability of the slope, PT Timah (Persero) Tbk. Can alter the slope’s geometry and install a grouted tieback anchors at unstable slopes.