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Simulasi Surge Tsunami Dengan Metode Dam Break Menggunakan Reservoar Terbatas
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The dam break method for simulating tsunami surges in the laboratory typically uses a sufficiently long flume, so that the upstream section of the flume, which serves as the reservoir, is also quite long. Using a long reservoir can provide a more extended simulation time for tsunami surge propagation on land, allowing the characteristics of the tsunami surge to be well observed. With a shorter flume, the reservoir space is also limited in length, and the simulation time for tsunami surge propagation is likewise constrained. This study aims to describe the characteristics of the simulated tsunami surge in comparison to the Chanson solution using a limited (short) reservoir. The tsunami surge simulation in a dry channel was conducted under the assumption of a limited reservoir with no bed slope. The water height in the reservoir varied from (d0) = 100 mm, 200 mm, 300 mm, and 400 mm, and the simulation was performed three times for each reservoir height. The tsunami surge simulation with downstream inundation was conducted similarly, but with an initial downstream inundation height of d1 = 100 mm and 150 mm, without initial velocity. The analysis results showed that the height and velocity of the tsunami surge from the simulation for both dry and inundated channels approached the results from Chanson's solution. This indicates that a limited flume length can be used to simulate tsunami surges with the dam break method, and that simulations with initial inundation can simulate the waveforms of undular bore and fully developed bore.Abstrak
Metode dam break untuk mensimulasikan surge tsunami di laboratorium biasanya menggunakan flume yang cukup panjang, sehingga bagian hulu flume yang merupakan ruang reservoar juga cukup panjang juga. Penggunaan reservoar yang panjang dapat memberikan gambaran waktu penjalaran surge tsunami di daratan saat simulasi yang cukup lama sehingga karakterisitk surge tsunami dapat teramati dengan baik. Penggunaan flume yang pendek maka ruang reservoar yang digunakan juga terbatas panjangnya dan waktu penjalaran surge tsunami saat simulasi juga terbatas. Penelitian ini bertujuan untuk menggambarkan karateristik surge tsunami hasil simulasi terhadap solusi Chanson menggunakan reservoar terbatas (pendek). Simulasi surge tsunami di saluran kering dilakukan dengan anggapan kondisi reservoar terbatas tanpa kemiringan dasar. Tinggi air di reservoar bervariasi dari (d0) = 100 mm, 200 mm, 300 mm, dan 400 mm dan simulasi dilakukan sebanyak 3 kali untuk tiap tinggi reservoar. Simulasi surge tsunami dengan genangan hilir dilakukan dengan cara yang sama tetapi di hilir saluran diberi genangan awal dengan tinggi d1 = 100 mm dan 150 mm dan tanpa kecepatan awal. Dari hasil analisis menunjukan bahwa tinggi dan kecepatan surge tsunami dari simulasi untuk saluran kering dan tergenang mendekati hasil dari solusi Chanson, kondisi ini menunjukkan bahwa panjang flume yang terbatas dapat digunakan untuk mensimulasikan surge tsunami dengan metode dam break, juga simulasi dengan genangan awal dapat mensimulasikan bentuk gelombang undular bore dan fully developed bore
Dynamic Analysis of Force Redistribution in Small Pile Groups Foundation Subjected to Accidental Lateral Loads
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Designing infrastructure always involves considering potential loads. Beyond anticipated loads, accidental ones can occur, as with the Pedamaran II bridge in Riau, where a ship collision damaged its foundation, breaking a pile and cracking the pile cap. However, this did not lead to structural failure, even though over 30% of the piles in the group were damaged. Initial hypotheses suggest that the use of bracing in the existing bridge might have helped redistribute forces. A numerical model was created using Opensees to simulate lateral loading on the shaft of an elevated pile cap, comparing the effects of bracing and no bracing using elastic elements in a simple 2x2 foundation model. The aim was to understand the correct modeling approach for bracing behavior and its impact on load response. Pushover analysis was performed on one of the shafts, with eccentric loading generating forces in both the x and y axes. Results showed that modeling bracing with elastic elements helped evenly distribute forces across rows of piles, with the greatest distribution occurring in the loaded row. The maximum moment occurred at the lowest bracing connection, highlighting the crucial role of bracing in load distribution, and significantly increasing lateral capacity by about 60%.Abstrak
Merancang infrastruktur tentu memperhitungkan beban rencana yang mungkin terjadi. Selain beban rencana, mungkin terjadi beban yang tidak disengaja seperti yang terjadi pada jembatan Pedamaran II di Riau. Terjadi kecelakaan pada jembatan dimana fondasi jembatan tertabrak oleh kapal hingga terjadi patah pada sejumlah tiang. Hal tersebut namun tidak membuat kegagalan struktur pada jembatan walaupun jumlah tiang yang patah mencapai lebih dari 30% dari jumlah tiang. Hipotesis awal adalah adanya dampak dari penggunaan bracing pada jembatan eksisting terhadap redistribusi gaya. Sehingga dilakukan pemodelan secara numerik menggunakan Opensees dengan memodelkan pembebanan lateral pada badan salah satu tiang dari sebuah elevated pile cap. Dilakukan pemodelan fondasi 2x2 secara tiga dimensi pada dua kondisi yaitu tanpa bracing dan bracing menggunakan elemen elastik. Tujuan dari penelitian adalah melihat pemodelan yang tepat untuk memodelkan perilaku bracing dan pengaruh bracing terhadap reaksi dari pembebanan. Letak beban yang eksentrik ini akan menimbulkan gaya pada sumbu x dan y. Disimpulkan pemodelan bracing dengan elemen elastik akan mendistribusikan gaya secara merata antar baris tiang, dimana distribusi paling besar terletak pada baris tiang yang dibebani. Momen maksimum terjadi pada sambungan bracing, sehingga menunjukan peran penting bracing dalam mendistribusikan beban. Kurva force-displacement menunjukan bracing akan meningkatkan kapasitas lateral sampai sekitar 60%
Literature Review: High Intensity Interval Training Meningkatkan Kebugaran Jasmani dan Sosial Status Pada Orang Dewasa Gaya Hidup Pasif
Get PDFWHO recommendations (2020) advise adults to do moderate intensity physical activity for 150-300 minutes (40-60% of Maximum Heart Rate) or high intensity physical activity for 75-150 minutes (60-85% of Maximum Heart Rate ) ) per week to maintain and improve fitness. However, often obstacles such as "lack of time", low motivation, and non-compliance with existing guidelines are reasons for not exercising. High Intensity Interval Training (HIIT) offers a solution that requires less time but still provides health benefits that are equal or even greater than the physical activity recommendations from WHO. This study aims to determine the effect of HIIT on physical fitness, VO2Max, and social status. The method used is library observation by searching for articles from electronic databases such as PubMed, ScienceDirect, and ProQuest. The research results show that HIIT can improve physical fitness, have a positive effect on social status significantly and efficiently.Rekomendasi WHO (2020) menyarankan orang dewasa untuk melakukan aktivitas fisik dengan intensitas sedang selama 150-300 menit (40-60% dari Denyut Jantung Maksimal) atau aktivitas fisik dengan intensitas tinggi selama 75-150 menit (60-85% dari Denyut Jantung Maksimal) per minggu untuk mempertahankan dan meningkatkan kebugaran. Namun, seringkali hambatan seperti "kurangnya waktu," motivasi rendah, dan ketidakpatuhan terhadap pedoman yang ada menjadi alasan untuk tidak berolahraga. High Intensity Interval Training (HIIT) menawarkan solusi dengan membutuhkan waktu yang lebih sedikit namun tetap memberikan manfaat kesehatan yang setara atau bahkan lebih besar dibandingkan dengan rekomendasi aktivitas fisik dari WHO. Penelitian ini bertujuan untuk mengetahui efek HIIT terhadap kebugaran jasmani, VO2Max, dan status sosial. Metode yang digunakan adalah tinjauan pustaka dengan mencari artikel dari database elektronik seperti PubMed, ScienceDirect, dan ProQuest. Hasil penelitian menunjukkan bahwa HIIT dapat meningkatkan kebugaran jasmani, memberikan efek positif terhadap status sosial secara signifikan dan efisien
POTENSI DESA WISATA BONJERUK SEBAGAI DESTINASI WELLNESS TOURISM
Get PDFThe general objective of this research was to analyze the potential of Bonjeruk Tourism Village as a wellness tourism destination based on tourism destination components and wellness tourism criteria. This study is a qualitative descriptive research. Data collection was done through literature review, observation and interviews. The results showed that Bonjeruk Tourism Village has tourism destination components in the form of attractions, amenities, accessibility, and ancillary services that are complete and in good condition. Bonjeruk Tourism Village also fulfills the criteria of wellness tourism, where tourists visiting Bonjeruk Tourism Village gain physical, mental, environmental and spiritual experiences. However, Bonjeruk's tourism potential is still in need of more focused development.Tujuan umum penelitian ini untuk menganalisis potensi Desa Wisata Bonjeruk sebagai destinasi wellness tourism ditinjau berdasarkan komponen destinasi wisata dan kriteria wellness tourism. Penelitian ini merupakan penelitian deskriptif kualitatif. Pengumpulan data dilakukan melalui studi literatur, observasi, dan wawancara. Hasil penelitian menunjukkan bahwa Desa Wisata Bonjeruk memiliki komponen destinasi wisata berupa atraksi, amenitas, aksesibilitas, dan ancillary yang lengkap dan dalam kondisi baik. Desa Wisata Bonjeruk juga memenuhi kriteria wellness tourism, yaitu wisatawan yang berkunjung ke Desa Wisata Bonjeruk memperoleh pengalaman fisik, mental, lingkungan, dan spiritual. Akan tetapi, potensi wisata Bonjeruk tersebut masih perlu dikembangkan secara lebih terarah
Criteria for Implementing Passive Strategies Utilizing a Biomimicry Approach in Vertical Housing Design
Get PDFThe issue of climate change and global warming has emerged as a significant concern confronting the world over the past decade. The substantial increase in temperatures observed during the last 10 years has led to a nearly threefold rise in sea levels compared to the period from 1901 to 1971. This escalation has precipitated natural calamities such as floods, landslides, extreme weather events, and alterations in rainfall intensity and patterns. Greenhouse gases, notably CO2, CH4, and N2O, generated by various energy-intensive activities, serve as primary drivers of global warming and climate change. Concurrently, buildings, including both residential and commercial structures, represent approximately 30-40% of global energy consumption and contribute over 30% of carbon emissions worldwide, particularly in urban settings. This surge in urbanization, particularly in major cities, not only escalates population density but also amplifies energy consumption. In tropical climates, energy usage in buildings predominantly caters to achieving thermal comfort, with air conditioning and lighting constituting significant portions of architectural design considerations. Strategies to address energy challenges in buildings range from enhancing energy efficiency to embracing renewable energy sources. It is imperative to undertake diverse initiatives to tackle these challenges without exacerbating environmental burdens that fuel climate change. Biomimicry, which involves emulating nature's designs and processes, offers a promising solution. Over the course of 3.8 billion years, millions of species have evolved and adapted to their environments, offering invaluable lessons on sustainability and resilience. By drawing inspiration from nature's solutions, humans can mitigate adverse impacts such as fossil fuel consumption and environmental pollution. Nature has perfected efficient systems and mechanisms to address myriad environmental challenges, including those posed by climate change. This research endeavors to explore various biomimicry approaches to enable buildings to harmonize with their surroundings and mitigate potential impacts through passive strategies in vertical residential designs tailored for tropical regions. Through the utilization of literature review methods and precedent studies, this research endeavors to formulate passive design criteria imbued with a biomimicry approach tailored for flat house design
Small Living Space Prototype Design Parameters for Low-Vision Sufferers
Get PDFLow vision is defined as chronic visual impairment that results in functional limitations, disabilities, and a vision problem that cannot be corrected by using assistive devices, drugs, or medical procedures. Attention to spatial design factors that allow people with low vision to move independently can improve their quality of life. The adaptation factor is essential in understanding the space for a person with low vision to minimize the possibility of accidents in their homes. Low vision sufferers rely on their memory or memory and their rest vision before utilizing their sense of touch in understanding space and making movements. Their ability to move in space is influenced by the legibility of the space captured through their rest vision and sense of touch. The legibility variables of the room include the clarity of the path in the layout, the geometric shape of the room, low light intensity, contrast of material and color, affordability of wall elements, and fixed position objects. These spatial legibility variables will ultimately enable low-vision sufferers to create a spatial mental map to help them move independently in the house without any accidents. This research is an experimental and participatory study to find design parameters that can help the movement of people with low vision without relying on memory or pre-existing memories. The objective is to validate spatial readability variables on a small dwelling prototype with the help of VR technology. The specified design parameters include 1) geometric layout that prioritizes path clarity; 2) affordability of wall elements and objects; 3) geometric object; 4) color contrast; and 5) fixed furniture and objects. The research involved twelve low-vision sufferer respondents aged 21 to 28 years old. This research aim to produce simple housing prototype design parameters that are friendly for people with low vision
Place Attachment of Sub-Komunal RISHA Semanggi as Temporary Housing for Kampung METAL RW 01 Mojo, Pasar Kliwon Residents
Get PDFThe case of slum settlements is a problem that has not been resolved which causes the urban vulnerability phenomenon. Kampung Improvement Programs in Surakarta was held in Kampung METAL RW 01 Mojo, Pasar Kliwon. From 2019 until 2022, residents affected by the arrangement of the Kampung METAL RW 01 Mojo have been temporarily moved to the Sub-Komunal RISHA Semanggi housing, a vertical communal housing built using the RISHA prefabricated structure module. This study aims to identify the significance and relevance of the adaptation process conducted by residents towards place attachments in the temporary house. The research data collection method used the Post-Occupancy Evaluation (POE) method through a questionnaire distributed to 45 of 56 households. The respondents were asked to choose their answers from a two-point Guttman scale and a five-point Likert scale. The POE results were then analysed using Analysis of Variance to determine the significance and relevance between fulfilled preferences and place attachment. The survey results show that the adaptation process mediates the relationship between preferences that have been fulfilled and place attachment. This simply shows that the more the residents' preferences are fulfilled, the more satisfied they are with their temporary housing, so they feel attached to it
A Study On Failure Stress and Fatigue Crack Rate Implemented to a Double Edge Notched Gusset Plate
No full textA gusset plate is a member of a bridge structure that is significantly subjected to cyclically varying loads. It may collapse after a certain number of cycles. However a single cycle may causes structural failure although the maximum stress (due to loading) is much less than the yield or the ultimate stress of the material. In a case of notched component under such conditions, high-intensity stress will occur at the zone of the notched component. Fracture mechanics is strongly recommended in a bridge design especially for joints. It will determine the moment at which fatigue cracks will occur and how far it has propagated. This study explores a fracture phenomenon of a steel gusset plate due to fatigue loading. Modeled as a double-edged notched plate, the failure stress is found to be less than the ultimate stress of the material. By assuming that crack closure exist, the results of this study provide a significant conclusion: under a constant failure stress the rate of fatigue growth increases as the crack propagates.
Keywords: Fracture mechanics, fatigue loading, stress intensity, double-edge notchedAbstrak
Pelat buhul adalah bagian dari struktur jembatan yang secara signifikan mengalami beban yang bervariasi secara berulang. Pelat buhul dapat runtuh setelah sejumlah siklus tertentu. Namun satu siklus dapat menyebabkan kegagalan struktur meskipun tegangan maksimum (akibat pembebanan) jauh lebih kecil daripada tegangan leleh atau tegangan ultimit material. Pada kasus komponen bertakik dalam kondisi seperti diatas, tegangan dengan intensitas tinggi akan terjadi pada zona komponen bertakik. Mekanika fraktur sangat direkomendasikan dalam desain jembatan terutama untuk sambungan. Mekanika fraktur akan menentukan saat dimana retak lelah akan terjadi dan seberapa jauh perambatannya. Penelitian ini membahas fenomena fraktur pada pelat buhul baja akibat beban lelah. Dimodelkan sebagai pelat bertakik bermata dua, tegangan runtuh ditemukan lebih kecil dari tegangan ultimate material. Dengan mengasumsikan adanya penutupan retak, hasil penelitian ini memberikan kesimpulan yang signifikan: di bawah tegangan runtuh yang konstan, laju pertumbuhan lelah meningkat seiring dengan perambatan retak.
Kata-kata Kunci: Mekanika fraktur, pembebanan kelelahan, intensitas tegangan, berlekuk dua sis
Optical Spectroscopy and Photoionization Model of Planetary Nebula NGC 6572
Get PDFWe investigated NGC 6572 through optical spectroscopy to determine its kinematical and chemical properties. Two intermediate dispersion spectra (R~5000) centered around Hα and Hβ were used to derive the nebular expansion velocity from emission lines associated with Hα, Hβ, [OIII], [NII], and [SII] ions. A low dispersion spectrum (R~1000) was used to determine the nebular electron temperature, density, and chemical composition. We performed photoionization modeling to construct a self-consistent nebular model, while intermediate-resolution spectral images showed the global elliptical structure of the nebula. The expansion velocity deduced from most of the emission lines is consistent with the typical expansion velocity of planetary nebulae, i.e., around 15-20 kms-1. The nebular physical properties align well with those determined by other studies. The nebular abundances were found to be lower than the solar abundances (except for oxygen) but still comparable with the abundances derived by other researchers. The photoionization model generated spectral lines that are consistent with the lines found in the observations. Further spectroscopic observations with higher resolution and wider range at various position angles will be very useful to reveal a more complete and detailed structure of the nebula and to improve the determination of the nebular physical properties
Analisis Hubungan Tingkat Aktivitas Fisik dan Status Gizi Pada Remaja di Lembaga Pembinaan Khusus Anak (LPKA) Bandung
Get PDFThis study aims to analyze the relationship between the level of physical activity and nutritional status in children fostered by the Lembaga Pembinaan Khusus Anak (LPKA). The research method used in this study is descriptive quantitative research with an observational study research design. The population used was 140 adolescents fostered by LPKA Bandung. The sampling technique used in this study used purposive sampling. So that the subjects used were 40 people. The instrument used to determine the level of physical activity is using the Baecke Physical Activity Questionnaire (BPAQ) and measuring nutritional status using the Body Mass Index (BMI). The findings in this study were that most of the research subjects had a moderate level of activity (52.5%) with normal / thin nutritional status (72.5%) while the rest had a mild level of physical activity (47.5%) with excess nutritional status (27.5%). In addition, there is a significant relationship between the level of physical activity with nutritional status with (pvalue 0.049) The conclusion of this study is that adolescents who have moderate physical activity levels mostly have normal / less nutritional status, while adolescents who have mild physical activity levels mostly have more nutritional status. In addition, there is a significant relationship between the level of physical activity and nutritional status in adolescents in LPKA Bandung.Penelitian ini bertujuan untuk menganalisis hubungan antara tingkat aktivitas fisik dengan status gizi pada anak binaan Lembaga Pembinaan Khusus Anak (LPKA) Bandung. Metode penelitian yang digunakan pada penelitian ini merupakan penelitian deskriptif kuantitatif dengan desain penelitian studi observasi. Populasi yang digunakan merupakan remaja binaan LPKA Bandung sebanyak 140 orang. Teknik sampling yang digunakan pada penelitian ini menggunakan purposive sampling. Sehingga subjek yang digunakan sebayak 40 orang. Instrumen yang digunakan untuk menentukan tingkat aktivitas fisik yaitu menggunakan Baecke Physical Activity Questionnaire (BPAQ) serta pengukuran status gizi menggunakan Indeks Massa Tubuh (IMT). Temuan pada penelitian ini yaitu diketahui bahwa sebagian besar subjek penelitian memiliki tingkat aktivitas sedang (52,5%) dengan status gizi normal/kurus (72,5%) sedangkan sisanya memiliki tingkat aktivitas fisik ringan (47,5%) dengan status gizi berlebih (27,5%). Selain itu, terdapat hubungan yang signifikan antara tingkat aktifitas fisik dengan status gizi dengan (p-value 0,049) Kesimpulan dari penelitian ini yaitu bahwa anak remaja yang memiliki tingkat aktivitas fisik sedang sebagian besar memiliki status gizi normal/kurang, sedangkan remaja yang memiliki tingkat aktivitas fisik ringan sebagian besar memiliki status gizi lebih. Selain itu, terdapat hubungan yang signifikan antara tingkat aktivitas fisik dan status gizi pada remaja di LPKA Bandung