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Perkuatan Lereng Tanah Batuan Breksi Menggunakan riprap Pada Kaki Tower SUTET 500 KV di Dekat Sungai dengan Pola Aliran Radial
Get PDFPembelokan aliran sungai dampak pembangunan waduk Cipayung-Ciawi menyebabkan kelongsoran pada tower transmisi 500 kV. Studi ini bertujuan untuk mensimulasikan tingkat kesetabilan lereng ketika dilakukan perkuatan menggunakan riprap dan beronjong pada kaki Tower untuk mencegah terjadinya longsor yang membahayakan tower.Analisa stabilitas lereng dalam penelitian ini menggunakan metoda limit equilibrium yang dilakukan dengan software Geostudio. Parameter input tanah diambil dari data hasil investigasi lapangan. Alternatif perkuatan yang dikaji adalah desain berupa kombinasi riprap dan bronjong. Dimensi riprap dimodelkan dengan lebar 9 m, kemudian divariasikan terhadap tinggi 1 m, 2 m, 3 m, dan 4 m. Analisa ditinjau dari dua kondisi, yaitu pada saat beban normal dan dengan pertimbangan gempa.Simulasi dengan beban gempa menunjukkan kondisi lereng eksisting tidak stabil dengan FS sebesar 0,796. Perkuatan menggunakan riprap dengan ketinggian 4 m dan lebar 9 m dan bronjong dapat meningkatkan stabilitas menjadi 1,251. Sedangkan untuk kondisi tanpa beban gempa, FS meningkat dari 1,788 menjadi 2,298
Analisis Deformasi Lereng Dengan Perkuatan Soil Nailing Pada Proyek Pembangunan Jalan Baru Batas Kota Singaraja - Mengwitani
Get PDFPembangunan jalan baru Bts. Kota Singaraja – Mengwitani (short cut 5-6) selesai pada bulan Desember Tahun 2019. Geometri jalan baru tersebut memiliki lereng buatan yang cukup tinggi. Beberapa lereng mencapai ketinggian 40 m dari permukaan jalan. Salah satu perkuatan pada lereng yang ada pada pembangunan jalan baru Bts. Kota Singaraja – Mengwitani adalah soil nailing. Kondisi saat ini lereng dengan perkuatan soil nailing dalam keadaan stabil. Namun perlu diperhatikan jika terdapat perubahan faktor lingkungan. Faktor tersebut adalah naiknya Peak Ground Acceleration (PGA) gempa. Variasi PGA dilakukan dengan nilai PGA 0,4g; 0.45g; 0,5g; dan 0,55g. Analisis deformasi dan stabilitas lereng menggunakan aplikasi Plaxis. Hasil analisis menunjukkan bahwa semakin meningkat nilai PGA maka deformasi pada puncak lereng semakin meningkat, sedangkan faktor keamanan semakin menurun. Peningkatan deformasi pada analisis ini memiliki hasil yang bervariasi dengan peningkatan beban gempa 0,05g, namun deformasi cenderung meningkat seiring dengan meningkatnya beban gempa. Untuk faktor keamanan, pada variasi beban gempa 0,4g;0,45g;0,5g terjadi penurunan rata-rata faktor kemanan sebesar 2,62%. Berdasarkan hasil analisis didapatkan prediksi saat lereng mengalami deformasi 0,09 m, faktor keamanan berada pada kondisi kritis (FK = 1). Deformasi ini dapat diukur dilapangan menggunakan inclinometer. Hal tersebut dapat digunakan untuk early warning sebelum lereng runtuh akibat gempa
Pengaruh Perkuatan Grouting Terhadap Beban Maksimum Yang Dapat Diterima Tanah Dasar Pada Ruas Jalan Lamongan - Gresik
Get PDFSalah satu metode perbaikan tanah pada tanah lempung cenderung ekspansif adalah Water-Cement grouting. Pertimbangan teknis dilaksanakannya pekerjaan grouting sepanjang 1,35 Km di ruas jalan Batas Kota Lamongan – Batas Kabupaten Gresik (Link 028.7) Km. Sby. 39+650 – 41+000 adalah struktur badan jalan banyak mengalami deformasi permanen dengan kondisi kestabilan subgrade diduga mempunyai CBR rendah sehingga badan jalan menjadi getar jika dilewati kendaraan bermuatan berat. Tujuan pelaksanaan grouting adalah untuk mengatasi deformasi permanen dengan perkuatan lapisan subgrade untuk meningkatkan kemampuan jalan dalam menahan beban yang melintas. Untuk mengetahui kemampuan subgrade di lokasi studi dalam menahan pembebanan existing maka dilakukan analisa terhadap besar beban maksimum (Pmak) yang dapat ditahan oleh lapisan subgrade pada kondisi sebelum dan setelah grouting. Analisa dilakukan secara numerik menggunakan Program Plaxis Versi.21. Faktor dari perkuatan water-cement grouting yang disimulasikan pada penelitian ini yaitu asumsi ketebalan lapisan grouting dengan 6 type jenis ketebalan sebaran grouting dan nilai parameter tanah campuran yang berasal dari 90% material tanah asli Lapis 1 Lempung Kelanauan dan 10% material grouting. Hasil analisa pemodelan menunjukkan nilai beban maksimum (Pmak) semakin meningkat pada tanah yang terdapat lapisan grouting. Nilai Pmak pada subgrade sebelum grouting sebesar 80,379 kN/m2 meningkat menjadi 347,582 kN/m2 pada tanah subgrade yang terdapat lapisan grouting setebal 2m. Semakin tebal lapisan grouting di intra layer subgrade maka semakin besar nilai Pmak yang diperlukan tanah untuk mencapai ultimate bearing capacity dan semakin kecil nilai penurunan tanahnya. Hal ini mengindikasikan tanah subgrade mengalami kenaikan daya dukung setelah dilakukan grouting
Analysis of The Injection Pressure Effect on Single Cylinder Diesel Engine Power with Diesel Fuel-Methanol Blend
Get PDFThe use of fossil diesel fuels still produces carbon dioxide emissions (CO2), sulphur dioxide (SO2), hydrocarbon emissions (HC), nitrogen oxide (NOx), and high total particles and carbon monoxide (CO). Moreover, the need for transportation of motor vehicles will always increase every year. The emission of exhaust gases resulting from the combustion process can essentially be reduced by improving fuel quality, the homogeneity of the fuel mixture, and regulating proper combustion. There are several ways to reduce exhaust emissions from diesel engines by providing precise injection pressures. This is done to get the perfect combustion. In addition, improving fuel quality is a way to reduce emissions of exhaust gases. Another one is by adding methanol to the diesel. The addition of methanol can reduce the emission of exhaust gas produced. The process of mixing the solar and methanol takes the addition of surfactants to obtain good homogeneity. Testing was conducted using simulation software with engine modeling. The result can be seen in the reduction and the addition of standard pressure 200 bar, that the emulsion fuel in SFOC (specific fuel oil consumption) suffered a decrease and increased by 0.2% and 0.3% at pressure 160 bar and pressure 240 bar. The fuel solution on SFOC suffered a decrease and an increase of 0.3% and 0.25% was produced by pressure 160 bar and pressure 240 bar. The highest NOx is produced by 240 bar injection pressures with Dexlite fuel while the lowest NOx is produced by 160 bar injection pressure with emulsion fuel
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No full textComparison of Embankment Reinforcement Requirements with Geotextileon Soft Soil with 2D and 3D Slope Stability Analysis Methods Nur Arfiati Shoffiana, Yudhi Lastiasih & Trihanyndio Rendy SatryaEvaluation of Smart Mobility Indicators in Responding COVID-19 Pandemic in Indonesia Shanty Y. Rachmat & Ganesha G. MangkoesoebrotoGeotechnical Mapping for Soil Physical and Mechanical Parameters andHard Soil Depth in Badung Regency Zefira Wisna Maulidha, Trihanyndio Rendy Satrya & Yudhi LastiasihThe Physical Integration of Smart Transportation Characteristics of Suroboyo Bus and the Feeder Cindy Nur Aziza Rahman, Eko Budi Santoso & Siti NurlaelaThe Adequacy of Public Bus Fleet During the Covid-19 Pandemic (Case of The Transjakarta Corridor 1 DKI Jakarta, Indonesia) Amanda Dian W.Kusumawardani, Ibnu Syabri, Fika Novitasari & Naya C. Drestalit
Managing the Past into Future: Materiality and Discourse on Cultural Landscape
Get PDFReferring to the understanding of landscape as a cultural construct, the notion of the cultural landscape is constituted by its essential elements: system, people, and the landscape itself. The nexus between these elements was philosophically developed in a recent discourse that challenges the separation between cultural and natural heritage. This "segregation" is based originally on the hegemony of western values, in which cultural heritage resides mainly in monuments and sites; meanwhile, natural heritage is formed by the scientific idea of nature and wilderness as something isolated from people.The landscape of Muara Muntai, a tiny settlement that has grown and developed on the riparian of Mahakam River, is characterized by the use of Ironwood or Eusideroxylon zwageri Teijsm (locally known as Kayu Ulin). This native plant of East Kalimantan is considered noteworthy, and in the perspective of ecology, is currently categorized as "threatened" due to deforestation in the last decades. For a couple of hundred years, locally-sourced Ironwood has been purposed and processed autonomously by the community as building and linkage-system material, creating a unique ambiance for Muara Muntai. The so-called modernization significantly changes the value of this native material: Ironwood building façades have been renovated into brick cement for the sake of practicality; Ironwood roads and bridges have been gradually paved with concrete to make way for motorized transportation.Noting that the spirit of the place resides as much in the meaning and symbolism of place as it does in the locus settings, it requires a holistic approach to understand the conflict between modernization and place identity. The case of Muara Muntai will showcase how values of cultural heritage and its attributes -also to what extent the integrity, i.e. wholeness and intactness-will be able to be read and interpreted to give an overall sense of continuity
Biodelignification on Sengon (Paraserianthes falcataria) and Pine (Pinus merkusii) Using White-Rot Fungus Phanerochaete chrysosporium for the Development of Pulp and Paper Industries in Indonesia
No full textIndonesia with its huge area of tropical forest is one of the biggest wood producing countries, thereby potential to become a big pulp and paper producing country. However, the present pulping/bleaching process uses chlorine that is very toxic to the environment. Biopulping process which reduce or eliminate the use of chlorine is therefore a very promising method. This research performs the biodelignification process using white-rot fungus Phanerochaete chrysosporium on Sengon (Paraserianthes falcataria) and Pine (Pinus merkusii) especially studies the effect of using different medium during incubation. Agar and okara were used for the base media in which the effect of important parameters such as mineral additive, buffering system and nitrogen content of the media were investigated. The highest degradation of lignin was 55% achieved on Sengon incubated for 30th days using buffered okara with nitrogen limited media. The research also shows that Sengon gives better results than Pine on the degree of its lignin degradation. The results also show that degradation of lignin always occurred together with the degradation of cellulose and hemmicellucose, although the degradation of the latter two materials is less than degradation of lignin. It was concluded from the experiment that more complete addition of nutrient with appropriate composition, appropriate adjustment of pH, water content, appropriate incubation time and temperature, would increase the degree of delignification and in the same time will decrease the degree of polisaccaride degradation
BEHAVIOR OF NATURAL AND TREATED SOIL WITH MICROORGANISMS UPON VARIOUS WATER CONTENT DUE TO DYNAMIC LOAD
Get PDFLiquefaction is a phenomenon where the saturated sandy soil experiences highly excess pore water pressure and loss of effective stress between soil particles simultaneously due to an earthquake. It will have an impact on building damage or failure which laid on sandy soil. Study location was selected at the New International Airport in Kulonprogo, Yogyakarta which was built on loose sandy soil and coincidentally categorized as highly earthquake zone. Based on this, an experiment model was carried out to analyze the behavior of sandy soil when stabilized with Aspergillus fungus as the microorganisms. The loads derived from dynamic loads (earthquake loads) and it will also analyze the changes of soil parameters after the soil stabilization. In a previous study using a fungus with the type of Rhizopus oligosporus, it resulted in a significant increase in soil consistency under certain conditions of water content. From the experiment, it is known that the appropriate percentage of soil mixture consists of ordinary sand with a percentage of 62% plus silt and clay with a percentage of 38%. Aspergillus fungus isolates at a concentration of 10-2 showed good tissue growth and without the presence of foreign substances