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"Gunung Endut memiliki potensi cadangan terduga sebagai pembangkit listrik tenaga panas bumi sebesar 80 MWe. Informasi geologi teknik seperti mekanika tanah, litologi batuan, tingkat pelapukan batuan, kekuatan batuan, serta kemiringan lereng menjadi hal yang fundamental dalam menentukan lokasi wellpad. Hal tersebut mendasari penelitian karakteristik geologi teknik perlu dilakukan untuk kepentingan penentuan titik wellpad. Metode penelitian berupa pemetaan geologi teknik dan uji laboratorium mekanika tanah. Dalam melakukan uji mekanika tanah, digunakan sampel tanah terganggu yang diambil menggunakan sekop. Hasil pemetaan geologi teknik menunjukkan daerah penelitian tersusun atas lima satuan geologi teknik, yaitu satuan tanah residual SP (RSP), tanah residual SW (RSW), andesit lapuk sedang (AM), andesit sangat lapuk (AH), dan tuf lapuk sempurna. Berdasarkan tingkat pelapukan, daerah penelitian terbagi menjadi tiga zona pelapukan, yaitu zona batuan lapuk tinggi (level 4), zona batuan lapuk sempurna (level 5), dan zona tanah residu (level 6). Hasil analisis mekanika tanah menunjukkan nilai kadar air 29,62%- 40,89%, nilai batas cair (LL) 28,56%-48,17%, indeks plastisitas (PI) 1,49%- 17,96% dominan agak plastis, indeks aktivitas 0,3-1,55 (inactive hingga active clays) dominan normal clays, potensi swelling sedang, kohesi (c) 0,814-7,364 kPa, serta sudut geser dalam (ф) 2,51⁰-20,9⁰. Analisis kelayakan menunjukkan daerah penelitian layak dibangun wellpad dengan kriteria pondasi dengan kedalaman 3 m, berat tanah 1,8 t/m3 , lebar pondasi 5 m, serta faktor keamanan 2,5 dapat menopang wellpad dengan daya dukung rata-rata 12,16 ton/m2.......Mount Endut has a potential reserve of 80 MWe as a geothermal power plant. Technical geological information such as soil mechanics, lithology, weathering level, rock strength, and slope are fundamental in determining the location of wellpad. This underlies the research on engineering geological characteristics that need to be carried out to determine the wellpad point. The research method is in the form of engineering geological mapping and soil mechanics laboratory tests. In carrying out soil mechanics tests, disturbed soil samples were used which were taken using a shovel. The result of the engineering geological mapping show that the research area is composed of five engineering geological units, namely residual soil unit SP (RSP), residual soil SW (RSW), moderately weathered andesite (AM), highly weathered andesite (AH), and completely weathered tuff. Based on the level of weathering, the study area is divided into three weathering zones, namely the highly weathered rock zone (level 4), the completely weathered rock zone (level 5), and the residual soil zone (level 6). The results of the soil mechanics analysis show that the water content value is 29.62%-40.89%, the liquid limit value (LL) is 28.56%-48.17%, and the plasticity index (PI) 1.49%-17.96% is slightly dominant. plastic, activation index 0.3-1.55 (inactive to active clays) dominant normal clays, moderate swelling potential, cohesion (c) 0.814-7.364 kPa, and internal shear angle (ф) 2.51⁰-20.9⁰. The feasibility analysis shows that the research area is feasible to build a wellpad with the criteria of a foundation with a depth of 3 m, soil weight of 1,8 t/m3 , a foundation width of 5 m, and a safety factor of 2.5 that can support a wellpad with an average carrying capacity of 12,16 tons/ m2."

"Bencana tanah longsor merupakan salah satu masalah yang sering terjadi pada proyek pembangunan jalan bebas hambatan yang dibangun diatas bumi. Tanah longsor pada pembangunan infrastruktur dapat dipengaruhi oleh faktor internal dan juga eksternal yang dapat membuat tanah menjadi labil. Sebelum mengidentifikasi longsoran, diperlukan adanya penyelidikan geologi teknik agar dapat diketahui penyebab longsor pada Proyek Jalan Bebas Hambatan Cisumdawu Fase II STA 20+575. Dalam menyelidiki longsor pada daerah penelitian akan dilakukan penyelidikan geologi teknik permukaan disertai dengan pengujian mekanika tanah pada sampel terganggu dan analisis kestabilan lereng untuk mengetahui nilai keamanan lereng (SF) serta nilai kuat geser tanah pada saat terjadi longsor. Analisis kestabilan lereng dilakukan dengan menggunakan pendekatan elemen hingga pada program PLAXIS 2D 8.2. Penyelidikan geologi teknik menunjukan daerah penelitian memiliki lahan asal perbukitan yang tersusun oleh batuan vulkanik lapuk. Hasil pemetaan geologi teknik menunjukan daerah penelitian tersusun atas 2 satuan geologi teknik, yaitu Satuan Tanah Lanau Plastisitas Tinggi (MH) dan Satuan Breksi Tufa Lapuk Sedang. Berdasarkan tingkat pelapukan batuan, batuan tanah pada daerah penelitian dapat dibagi menjadi 5 zona, yaitu SWZ, MWZ, HWZ, CWZ, dan RSZ. Hasil analisis SF lereng sebelum longsor menunjukan nilai SF = 1.133 (kritis) yang disebabkan oleh 3 hal, yaitu sifat tanah ekspansif, penurunan nilai kuat geser tanah, dan curah hujan sedang pada daerah penelitian. Untuk menangani longsor diperlukan perkuatan struktur agar lebih efisien dengan perkuatan struktur tiang bor (bored pile) dan pasangan batu (stone masonry) pada kaki lereng. Hasil SF lereng setelah diberi perkuatan struktur menunjukan angka SF = 1.449.......Landslide disaster is one of the problems that often occur in highway construction projects built on earth. Landslides in infrastructure development can be influenced by internal and external factors that can make the soil unstable. Before identifying a landslide, it is necessary to conduct a geological engineering investigation to determine the cause of the landslide in the Cisumdawu Highway Project Phase II STA 20+575. In investigating landslides in the research area, surface engineering geological investigation will be carried out accompanied by testing of soil mechanics on disturbed samples and slope stability analysis to determine the slope safety factor (SF) also the value of soil shear strength during landslides. Slope stability analysis was carried out using the finite element approach in PLAXIS 2D 8.2 program. Engineering geological investigations show that the research area has hilly origins composed of weathered volcanic rocks. The results of the engineering geological mapping show that the research area is composed of 2 engineering geological units, namely the High Plasticity Silt Soil Unit (MH) and the Medium Weathered Tuff Breccia Unit. Based on the level of rock weathering, the soil rocks in the study area can be divided into 5 zones, namely SWZ, MWZ, HWZ, CWZ, and RSZ. The results of the SF analysis of the slope before the landslide showed the SF value = 1,133 (critical) which was caused by 3 things, namely expansive soil properties, decreased soil shear strength, and moderate rainfall in the study area. To deal with landslides, it is necessary to strengthen the slopes with structural reinforcement using bored pile and stone masonry at the foot of the slope. The results of the SF slope after being given structural reinforcement show the number SF = 1.449."