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Potential Collapse Based on Discontinuity Plane In The Andesite Quary Of Mount Geulis, Jatinangor District, Sumedang Regency, West Java Taufiq, Mochamad Muslim; Sophian, Raden Irvan; Khoirullah, Nur; Zakaria, Zulfialdi
Journal of Geological Sciences and Applied Geology Vol 5, No 2 (2021): Journal of Geological Science and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v5i2.34878

Abstract

Landslide are natural disasters that often occur in West Java, in 2020 landslides have occurred 852 times. In an effort to prevent the occurrence of rock landslides, it is necessary to study the stability of rock slopes, so it is necessary to evaluate the discontinuity of the rock and take engineering geological. The purpose of this study is to analyze the stability of rock slopes in the study area so that the types of landslides that can occur can be known. Method used is Kinematic Analysis where the object of research is an andesite outcrop located at the northwest foot of Mount Geulis, Cinanjung Village, Jatinangor District. Kinematic analysis is an analysis of the movement of objects without considering the forces that cause them. Various types of slope failure are associated with geological structures that result in a discontinuity plane in the rock body. The results of the study are in the form of determining the potential for landslides that can occur in the research area. Based on the kinematic analysis of the types of failure in the research area that can occur are wedge types in the MT-2, MT-5, and MT-6 segments and toppling types in the MT-3, MT-4, MT-7 segments and Planar failure found in the MT - 1 segment. potential failure in the study area are toppling and wedge with percentage values for the possibility of landslides were obtained, namely: wedge failure is 1.82% - 3.91% and toppling failure is 21.82% - 38.95% and Planar failure is 55.81%
HUBUNGAN NILAI GAMMA RAY DENGAN BATUAN PIROKLASTIK DI DAERAH CIBIRU DAN SEKITARNYA, KOTA BANDUNG, PROVINSI JAWA BARAT Hadiasti, Widia; Muslim, Dicky; Zakaria, Zulfialdi
Bulletin of Scientific Contribution Vol 14, No 1 (2016): Bulletin of Scientific Contribution
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1231.249 KB) | DOI: 10.24198/bsc.v14i1.9787

Abstract

Surface gamma ray measurements were conducted at 40 sites in Cibiru area, Bandung, West Java. This location is part of Digital Topographic Map of Indonesia (Bakosurtanal) Lembar Bandung (Silitonga, 1973).  Geographically is located between E 1070 42’ 22” to 1070 45’ 05” and S 060 53’ 30” to 060 57’ 15”. This study aims to determine the value of gamma ray measured, its relationship with the content of feldspar minerals and its relationship with pyroclastic rock. Geological mapping was conducted in this research area and gamma ray measured using a gamma ray detector Radi PA-100 Horiba, and then carried out petrographic analyses of rock samples to determine the mineral content. The result reveals that the study area is consisted of coarse tuff, fine tuff and volcanic breccia with gamma ray values are different at each sites. The average value of gamma ray in coarse tuff is 0.046 ± 0.028 nSv/h, in fine tuff is 0.046 ± 0.028 nSv/h and for breccia is 0.059 ± 0.018 nSv/h. High feldspar mineral content contained in the breccia 79%, and low feldspar mineral content in fine tuff 13%. The study reveals that the value of gamma ray is relationship with the content of feldspar mineral. The relationship between value of gamma ray and pyroclastic rock that can be known from the content of feldspar mineral. High feldspar mineral content contained in pyroclastic rock that are intermediate to acid. Keywords : gamma ray,  feldspar, pyroclastic rocks.Pengukuran nilai gamma ray telah dilakukan pada 40 stasiun di daerah Cibiru dan sekitarnya, Kota Bandung, Provinsi Jawa Barat. Secara administratif, lokasi penelitian tercakup dalam peta topografi Lembar Bandung (Silitonga, 1973) skala 1:25000 dan secara geografis daerah penelitian terletak pada 1070 42’ 22” BT sampai 1070 45’ 05” BT dan 060 53’ 30” LS sampai 060 57’ 15” LS. Penelitian ini bertujuan untuk mengetahui nilai gamma ray dengan batuan piroklastik dilihat dari kandungan mineral feldspar (plagioklas  (NaAlSi3O8) dan k-feldspar (KAlSi3O8)) pada batuan. Metode penelitian yaitu dengan melakukan pemetaan geologi dan pemetaan nilai gamma ray dilakukan dengan menggunakan alat detektor Radi PA-100 Horiba kemudian dilakukan analisis petrografi untuk mengetahui kandungan mineral feldspar ( plagioklas dan k-feldspar) pada batuan. Hasil penelitian menunjukkan bahwa litologi penyusun daerah penelitian memiliki nilai gamma ray yang berbeda-beda. Nilai gamma ray pada Satuan tuf kasar rata-ratanya yaitu 0,046 ± 0,028 µSv/h, pada Satuan tuf halus rata-ratanya yaitu 0,047 ± 0,021 µSv/h dan rata-rata nilai gamma ray pada breksi yaitu 0,059 ± 0,018 µSv/h. Hubungan nilai gamma ray dengan batuan piroklastik dapat diketahui dari kandungan mineral feldspar yang terdapat dalam tuf kasar, tuf halus dan breksi monomik. Semakin tinggi kandungan mineral feldspar pada tuf kasar, tuf halus dan breksi monomik maka nilai gamma ray-nya pun makin tinggi dan sebaliknya. Komposisi mineral feldspar yang tinggi (unsur K tinggi) terdapat dalam batuan piroklastik yang bersifat menengah sampai asam. Kata kunci : gamma ray, feldspar, batuan piroklastik. 
HUBUNGAN ANTARA PHYLLIC ALTERATION DENGAN NILAI KEKUATAN BATUAN DI UNDERCUT LEVEL TAMBANG GRASBERG BLOCK CAVE (GBC) PT. FREEPORT INDONESIA Zakaria, Firman; Zakaria, Zulfialdi; Syafri, Ildrem; Wiguna, Purwa
Bulletin of Scientific Contribution Vol 15, No 3 (2017): Bulletin of Scientific Contribution:GEOLOGY
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (836.015 KB) | DOI: 10.24198/bsc.v15i3.15101

Abstract

ABSTRACTThe Grasberg Block Cave (GBC) underground mine consists of multiple intrusion stages become into the Grasberg Intrusion Complex (GIC). The intrusion is consists of three intrusion stages, Dalam Intrusion Complex (DIC), Main Grasberg Intrusion (MGI) and Kali Intrusion (KI). The emplacement of intrusions occurred in a relatively short span between 3.51Ma (Dalam stage), 3.21Ma (Main Grasberg stage) and 3.1Ma (Kali stage). The existence of magmatic activity that occurs is the main control of mineral formation changes that affect the condition of rocks and quality of Cu-Au. Different type of alteration and mineralization on GIC rock can change its physical properties. Variations of mineral alterations that are formed due to the variation of intrusion causes the variation of mineral alteration that affect the value of rock strength. The value of rock strength affects the determination of rock support that will be mined in the Grasberg Block Cave underground mine (GBC). XRD analysis with mineral content dominance quartz 30.07%, sericite 22.72%, k-feldspar 13.38%, fe sulphide 9.80% and CaSulfate 5.72%. XRD analysis results are type of phyllic alteration. Point load analysis in the research area of 347 pieces of rock drill hole found rock strength value is dominated by weak (0.2 – 1 Mpa) - medium (1 – 2 Mpa). Rock Mass Rating (RMR) analysis calculation result value is RMR 20 - 60 (poor - fair). Keywords: Grasberg Block Cave, phyllic alteration, XRD Analysis, Point Load Test analysis,  ABSTRAKTambang bawah tanah Grasberg Block Cave (GBC) terdiri dari beberapa tahapan intrusi yang tergabung ke dalam jenis Komplek Batuan Beku Grasberg (GIC). Tahapan intrusi dari tua ke muda adalah Dalam Intrusion Complex (DIC), Main Grasberg Intrusion (MGI) dan Kali Intrusion (KI). Adanya aktifitas magmatik yang terjadi merupakan kontrol utama pembentukan mineral ubahan yang berpengaruh terhadap kondisi batuan. Variasi mineral ubahan yang terbentuk akibat dari adanya variasi intrusi menyebabkan adanya variasi mineral ubahan yang berpengaruh terhadap Tambang bawah tanah Grasberg Block Cave (GBC) terdiri dari beberapa tahapan intrusi yang tergabung ke dalam jenis Komplek Batuan Beku Grasberg (GIC). Tahapan intrusi dari tua ke muda adalah Dalam Intrusion Complex (DIC), Main Grasberg Intrusion (MGI) dan Kali Intrusion (KI). Adanya aktifitas magmatik yang terjadi merupakan kontrol utama pembentukan mineral ubahan yang berpengaruh terhadap kondisi batuan dan kualitas cebakan Cu-Au. Variasi mineral ubahan yang terbentuk akibat dari adanya variasi intrusi menyebabkan adanya variasi mineral ubahan yang berpengaruh terhadap nilai mekanika batuan. Analisa XRD dengan dominasi kandungan mineral quartz 30.07%, sericite 22.72%, k-feldspar 13.38%, fe sulphide 9.80% dan casulfate 5.72%. Hasil analisis XRD tersebut masuk ke dalam tipe phyllic alteration. Analisis uji kuat tekan batuan (Point Load Test) pada daerah penelitian terhadap 347 buah conto batuan lubang pemboran memberikan nilai kekuatan batuan didominasi oleh nilai kekuatan batuan lemah (weak, 0.2 – 1 Mpa) - sedang (medium, 1 – 2 Mpa). Kata kunci: Grasberg Block Cave, phyllic alteration, XRD Analysis, Point Load Test.
Analysis of the Process of Handing Over Housing Infrastructure, Facilities, and Utilities that have been Implemented in Indonesia Agustini, Amanah Putri; Ningrum, Sinta; Zakaria, Zulfialdi
Publik : (Jurnal Ilmu Administrasi) Vol 13, No 2 (2024): December 2024
Publisher : Universitas Muhammadiyah Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31314/pjia.13.2.185-194.2024

Abstract

The goal of housing and settlement development is to create an environment and human living space that meets the essential needs of life, including security, protection, tranquility, self-development, health, beauty, and other necessities for the preservation of human life. The purpose of this study is to find out the policy of the process of handing over infrastructure, facilities, and housing utilities that have been implemented in areas in Indonesia. This study uses a case study method, namely by reviewing previous studies, to conclude. The results of the study show that there are several stages in the process of handing over housing infrastructure, facilities, and utilities in Indonesia, namely there is a stage of providing and developing infrastructure, facilities, and housing utilities, there is a stage of handing over housing infrastructure, facilities, and utilities from development to the district government, and finally there is a stage of registration or administration of housing infrastructure, facilities, and utilities. In addition, in the process of handing over, there are several weaknesses that are still faced by the local government in its policies, namely, location permits that are not recognized, weak law enforcement against housing developers, and the weakness of the housing monitoring team.