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DESAIN GEOMETRI LERENG OPTIMAL PADA RENCANA PENGGALIAN ULANG MATERIAL TIMBUNAN BERDASARKAN PARAMETER GEOTEKNIK MELALUI PENDEKATAN TINGKAT PEMADATAN TIMBUNAN

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Penilaian

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PT Bukit Asam, Tbk (PTBA) is one of the companies engaged in coal mining. One of the mining areas within PTBA's IUP is Pit X. Pit X is a former disposal area that was re-excavated because, based on the feasibility study by the PTBA Planning Team, it is still economically feasible to be mined, so in 2018 mining operations began again in Pit X starting with the loading of old dumped material called the old dump.. PTBA strives to maximize the coal reserves in Pit X. Maximizing coal reserves can be done by optimizing the slope design geometry. The material properties in this old dump material should not be considered the same (homogeneous) because it consists of various types of material and historically, Pit X was backfilled using a spreader from a bucket wheel excavator which tends to result in different levels of compaction. This study aims to analyze and process the material properties that will be used in analyzing slope stability in Pit X as well as analyzing the optimal overall slope geometry in Pit X. The determination of material properties used for the slope stability analysis of Pit X was carried out by creating cross sections that considered the locations of the nearest boreholes. Data from the boreholes were processed using a classification and interval approach for each material property. The values used were the midpoints of each class. Specifically for cross section C–C’, further analysis was conducted by creating several models using combinations of data from boreholes ABC 13 & ABC 360, ABC 13 & ABC 16, and ABC 13 & ABC 10. Each model was analyzed to obtain the Factor of Safety (FoS) value. The model using data from boreholes ABC 13 & ABC 10 was selected to represent the material properties for cross section C–C’ because it produced a FoS value that most closely matched that of cross section D–D’. The most optimal overall slope geometry uses a single slope height of 6 meters with a 27° angle (slope ratio 1:2) and a bench width of 23 meters. This slope geometry is applied to all cross sections, resulting in a dynamic Factor of Safety (FoS) of 1.216 and a static FoS of 1.393 on cross section A-A’, a dynamic FoS of 1.552 and a static FoS of 2.016 on cross section B-B’, a dynamic FoS of 1.529 and a static FoS of 1.760 on cross section C-C’, and a dynamic FoS of 1.585 and a static FoS of 1.827 on cross section D-D’. These values are considered safe. The Factors of Safety were calculated under the condition of the highest groundwater level, which occurs immediately after rainfall with a rainfall intensity of 110.08 mm and a duration of 4.18 hours.

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Availability

Inventory Code	Barcode	Call Number	Location	Status
2507002804	T173106	T1731062025	Central Library (Reference)	Available but not for loan - Not for Loan

Detail Information

Series Title

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Call Number

T1731062025

Publisher

: Prodi Magister Teknik Pertambangan, Fakultas Teknik Universitas Sriwijaya., 2025

Collation

xiv, 36 hlm.; ill.; tab.; 29 cm.

Language

Indonesia

ISBN/ISSN

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Classification

622.07

Content Type

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Media Type

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Carrier Type

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Edition

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Subject(s)

Teknik Tambang

Specific Detail Info

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Statement of Responsibility

EM

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