THE APPLICATION OF FAILURE METHOD PROBABILITY FOR ANALYZING IN PIT DUMP STABILITY AT WEST BLOCK ‘X’ PIT PT BERAU COAL - EAST KALIMANTAN

West Block 'X' pit is one of the coal mining locations operated by the Lati Mine Operation – PT Berau Coal. Administratively, the Lati Mine is located as part of Berau Regency – East Kalimantan. The study area is located at the north side of the concession, in a syncline fold structure zone. The disposal design in this area needs to special attention from slope stability aspect due it is located on the wing of a mega syncline with a certain slope and constituent of unconsolidated materials. The pit design needs to be stable. The purpose of this study is to determine the level of stability of the in-pit dump by analyzing the current in-pit dump stability based on the value of the safety factor (FS) and the probability of failure (PoF). The method used in this study is a probabilistic analysis of slope stability based on the Morgenstern-Price method to obtain the value of the safety factor and the probability of failure. The study results show that the slope is in the safe category (stable slope) in the range of PoF values 0 – 1%, marginal slope 1 – 12%, and unstable slope above 12%. Based on such as results, it is necessary to modify the slope geometry categorized as unstable to carry out mine operation safely underneath the toe of slope

KEMAMPUGALIAN KUARI ANDESIT GUNUNG GEULIS, KECAMATAN JATINANGOR, KABUPATEN SUMEDANG, PROVINSI JAWA BARAT

Kebutuhan bahan baku batu andesit semakin meningkat seiring dengan perkembangan dan percepatan infrastruktur di Indonesia. Batu andesit dapat dimanfaatkan sebagai bahan baku dalam pembuatan trotoar jalan, pondasi bangunan atau dapat dijadikan sebagai bahan campuran beton. Dalam kegiatan penambangan batu andesit, diperlukan analisis untuk ketepatan penggunaan metode penambangan agar tercipta usaha pertambangan yang berdaya guna, menunjang efektivitas dan efesiensi pekerjaan serta biaya operasional. Penelitian ini dilakukan untuk mengetahui kelas massa batuan, tingkat kemampugalian batuan dan rekomendasi bentuk lereng untuk kegiatan penambangan agar dapat berjalan dengan efektif dan efisien. Metode penelitian yang digunakan adalah klasifikasi geomekanik dengan sistem rock mass rating (RMR), slope mass rating (SMR) dan analisis kemampugalian batuan. Berdasarkan klasifikasi geomekanik tersebut, diketahui kelas massa batuan memiliki kategori good rock dengan nilai RMR 69 – 79 dan SMR 53° - 65°. Metode penggalian yang disarankan berupa ripping-blasting

Tropical Volcanic Residual Soil

In West Lampung, Sumatra, Indonesia, tropical volcanic residual soils are formed from weathering of volcanic breccias in hydrothermal alteration areas with a thickness of up to 20 m. This soil has the characteristics of clayey silt, low to high plasticity, brownish-red color, has the potential to swelling, easily eroded, and slide when it is saturated, and contains the minerals kaolinite, halloysite, illite, dickite, nacrite, montmorillonite, despujolsite, hematite, and magnetite. The results showed that this soil can cause corrosion of steel and is widely used by the community as a medium for growing plants and vegetables and as a foundation for infrastructure (for example, houses). The volcanic residual soil of the research area had Low Rare Earth Element (LREE) potential and specific uses. The soil with characteristic low plasticity has Liquid Limit (LL) brine value 50%, was more ideal for the primary forest

Pemodelan Indeks Pembangunan Gender (IPG) Provinsi Jawa Timur dengan Pendekatan Metode Regresi Logistik Ridge

Pembangunan Sumber Daya Manusia (SDM) mulai tahun 2019 menjadi pilihan strategi untuk mengakselerasi pertumbuhan ekonomi yang dibutuhkan dalam meningkatkan kesejahteraan rakyat. Dalam mendukung sumber daya manusia yang berkualitas dan berkompeten, tentunya harus menyeimbangkan peran antara SDM perempuan dan SDM laki-laki. Indeks Pembangunan Gender (IPG) merupakan indikator yang menggambarkan perbandingan capaian antara IPM perempuan dengan IPM laki-laki. IPG memiliki tiga komponen pembentuk yakni dimensi Kesehatan, pengetahuan, dan ekonomi. Dalam setiap sektor cenderung memiliki kolinieritas yang tinggi sehingga menyebabkan kasus multikolinieritas. Upaya menyelesaikan permasalahan multikolinieritas dan struktur data IPG Provinsi Jawa timur yang telah dikategorikan adalah menggunakan metode Regresi Logistik Ridge. Data yang digunakan berbentuk rasio dengan variabel sebanyak tujuh belas dimana terdapat tiga variabel yang berpengaruh signifikan, yaitu rasio penduduk usia 5 tahun keatas yang tidak mengonsumsi tembakau, rasio lulusan D4 dan S1, dan rasio angka partisipasi murni (APM) SMA, Dengan metode Regresi Logistik Ridge, didapatkan Ketepatan Klasifikasi, Akurasi, Sensitivitas, dan Spesifitas model lengkap dari Indeks Pembangunan Gender (IPG) untuk kabupaten/kota di Provinsi Jawa Timur dengan menggunakan metode Regresi Logistik Ridge sebesar 81%, 87%, 94%, dan 80%. =============================================================================================================================== Human Resource Development (HR) starting in 2019 is a choice of strategy to accelerate economic growth needed to improve people's welfare. In supporting quality and competent human resources, of course, it must balance the role between female human resources and male human resources. The Gender Development Index (IPG) is an indicator that describes the comparison of achievements between women's HDI and men's HDI. IPG has three constituent components, namely the dimensions of health, knowledge, and economy. Each sector tends to have high collinearity, causing cases of multicollinearity. Efforts to solve the problem of multicollinearity and IPG data structure of East Java Province that have been categorized are using the Ridge Logistic Regression method. The data used is in the form of a ratio with seventeen variables where there are three variables that have a significant effect, namely the ratio of residents aged 5 years and over who do not consume tobacco, the ratio of D4 and S1 graduates, and the ratio of pure participation rate (APM) of SMA, With the Ridge Logistic Regression method, Accuracy of Classification, Accuracy, Sensitivity, and Specificity of a complete model of the Gender Development Index (IPG) for districts / cities in East Java Province using Ridge Logistic Regression methods of 81%, 87%, 94%, and 80%

Swelling potential of volcanic residual soils in Sumatra (Indonesia) in relation to environmental issues

Swelling potential characterization of clay-silt soil is an essential issue in stabilization, settlement, consolidation, and land suitability studies. This article attempts to explain the swelling characteristics of soils around the area of West Lampung, Lampung Province, Sumatra, Indonesia, in relation to environmental issues. An investigation in relation to the soil swelling potential was carried out using 15 disturbed soil samples collectd in the study area. The methods used were analyses of clay mineral geochemistry, physical characteristics, and the free swell ratio. These results showed that the soil in the study area was Quaternary tropical volcanic residual soil. These soils were formed in a proximal volcanic hydrothermal alteration environment. The soils of the study area have characteristics of high plasticity, a reddish-brown colour, and are clayey silt grained (MH) (USCS). The soils had loose physical characteristics in dry conditions; however, these soils tends to be plastic and sticky in wet conditions. Evidence of groove erosion was found at the soil surface. Based on XRD analysis, kaolinite, halloysite, and montmorillonite were types of clay minerals found in the soil. The soil had a clay content of 11.05–78.9%, a liquid limit value > 50%, a plasticity index value of 16.7–36.9%, a shrinkage value of 14.24–36.89%, a soil activity of 0.38–2.47; and an FSR value of 0.69–0.95. These characteristics have implications for swelling soil potential. The results showed that the soils in the study area had medium to very high swelling potential. These results suggest a risk of erosion in the area, which could cause soil degradation and a change in water quality. These soils are likely to affect land productivity and aquifer replenishment and will cause negative environmental and economic impacts. Thus, soil improvement techniques are needed. It is important to maintaining vegetative cover these soils and revegetation may be required