Kajian Model Fisik Pengaruh Freeboard dan Susunan Buis Beton sebagai Pemecah Gelombang Tenggelam Ambang Rendah (Pegar) dalam Mereduksi Gelombang

The Research Center and Development of Water (Puslitbang) is currently developing the Submerged Breakwater in shallow sea area (PEGAR). The author is interested to examine the material that  easily obtained in the field of RCP concrete cylinder. The observation is how it to be ability in function as submerged breakwater an go green and low cost. The physical model of wave transmission test is how the response to the structure in ability to damping of wave as the breakwater function. In this research breakwater used is submerged breakwater type by using concrete cylinder (buis beton). The purpose from this research is to know how the response of breakwater structure to the waves through it, with some variation of the structure by creating a structure with three variations of the arrangement and freeboard that is the relative depth with the crest width is constant. The wave generated test in this study is using regular waves in wave flume at FTSP Civil Engineering Department of Institute Technology Ten November. From the analysis of the effect of the installation of submerged breakwater by using concrete cylinder to the wave damping value, it can be concluded that the factors that are very influential is the freeboard and the composition of concrete cylinder. Scenario A (rigid vertical massive) is capable of producing the smallest value of kt is 0.33. As for scenario B (rigid horyzontal massive) with a damping value of 0.5, while the scenario C (rigid permeable) is only able to  produce kt value of 0.71. Scenario A is better than scenario B and C Because the position of arrangement of A is very good used to damp wave in small or big freeboard conditions

Identifikasi Kelemahan Metode Earned Value pada Pengukuran Kinerja Biaya dan Waktu Proyek Konstruksi

Earned Value method (EV) has several weaknesses which makes it difficult to optimally apply in the construction projects. This study aims to identify the shortcomings of Earned Value related to the project cost and time performance. Literature study was conducted from the various sources related to the EV topic. The result shows that the main weakness of Earned Value method are: EV prediction method is assumed deterministic, linear, non-dynamic and does not accommodate uncertainty factors of time and cost of construction projects

Comparative Analysis of Water Resources Management Service Costs for Delta Brantas Irrigation Area

A proper fuction of irrigation system needs sustainable water resource management, supported by Water Resources Management Service Costs (BJPSDA). BJPSDA is a partial reimbursement of the cost required for water resource management activities, especially for operation and maintenance activities, must be calculated and set by water resources management. There are two methods that are used to calculate BJPSDA, which is BJPSDA in accordance with the Regulation of the Minister of Public Works and Public Housing No. 18/PRT/M/2015 and BJPSDA using basic service fee by considering the quality of service and value of economic benefits modelling. This study was conducted by comparing two BJPSDA methods in the Delta Brantas Irrigation Area and will be analyzed descriptively. BJPSDA of irrigation in accordance with Regulation of the Minister of Public Works and Public Housing No. 18/PRT/M/2015 is Rp. 255,-/m3, as cost recovery.. BJPSDA of irrigation value using basic service fee by considering the quality of service and value of economic benefit modelling amounted Rp. 338,-/m3, calculated from basic service fee amounted Rp. 177,-/m3, added with NME for agriculture water in Delta Brantas Irrigation Area amounted Rp. 161/m3, as a water value

Studi Optimasi Pola Tanam Pada Daerah Irigasi Warujayeng Kertosono Dengan Program Linier

Daerah Irigasi Warujayeng Kertosono berada di wilayah Kabupaten Nganjuk yang melewati Kecamatan Tanjunganom, Kertosono, dan Lengkong dengan luas baku sawah 12,384 Ha. Sumber air irigasi dari Kali Brantas melalui Bendung Gerak Mrican dengan pengambilan dari pintu Mrican Kiri. Terbatasnya jumlah air di musim kemarau dapat mengurangi pemberian air ke sawah. Untuk memaksimalkan produksi tani perlu peningkatan produktivitas lahan dan pemberian air yang teratur sesuai dengan kebutuhan dan persediaan. Untuk analisa ini digunakan program linier Quantity Methods for Windows 3 dengan input kebutuhan air tiap jenis tanaman dan volume andalan sebagai kendala/batasan untuk pengoperasian program linier. Output dari program ini ialah luas sawah maksimum tiap jenis tanaman, musim tanamnya dan keuntungan hasil tani yang didapat. Dari beberapa alternatif rencana, didapat pola tanam yang menghasilkan keuntungan terbesar yaitu pola tanam padi-tebu, padi-palawija-tebu, palawija-tebu pada awal tanam Nopember 1 dengan keuntungan Rp. 281,541,700,000.00 dan intensitas tanam 300 %

Analysis of Waikelo Port Breakwater Failure through 2D Wave Model

Waikelo Port is located in South West Sumba of East Nusa Tenggara. The port facilities are protected by breakwater with a vertical wall construction and it was built in a relatively deep ocean at -15m of Low Water Sea Level (LWS). On 21 of January 2012, an earthquake with magnitude of 6.3 Richter scale occurred around Sumba Island and it caused cracking in the concrete wall of breakwater. Then, 4 days after on 25 st January 2012, a heavy wind of 20–23 knots generated a high wave around 4.0–5.0m in Sumba strait. These high waves caused a critical damage on the west part of the breakwater. The damage of port facilities were getting worse when a storm called Lua hit on March 2012. This study was conducted to observe the effect of the extreme event in the failure of breakwater. The result of two-dimensional (2D) wave model shows that the wave heights in the area of breakwater are varied 3.80 to 4.0m. It is quite greater than the wave design of 50 years return period (= 2.00m) which was used in breakwater design and calculation. This observable fact confirms that the failure of breakwater was caused by the continuous extreme events that exceed the design criteri

Aplikasi Metode Curve Number Untuk Mempresentasikan Hubungan Curah Hujan Dan Aliran Permukaan Di DAS Ciliwung Hulu – Jawa Barat

Run off (surface flow) is one of the most important hydrological variable in supporting the activities of water resources development. A reliable prediction method to calculate the amount and rate of runoff from the land surface caused by the rain that falls in a watershed that is not equipped with measuring devices (un gauge watershed) is a verydifficult job and requires a lot of time. The research was conducted in the watershed Ciliwung Hulu, which is an important area in relation to the incidence of flooding in Jakarta. Curve Number (CN) method can be used to predict the amount of runoff from a watershed. This model required input of rainfall; land cover maps; soil type maps,and topography. The maps are processed using Arc View software, so we get the value of CN. In this study, we used of rainfall and discharge data 2007-2009. Based on the analysis of calculation, known that amount of surface flow approaching 50% of rainfall depth. This condition indicates that the Ciliwung Hulu watershed conditions were not ableand proper to absorb of rainfall. The correlation between the results of run-off prediction models using CN with run-off observation was quite good. This indicated that the Curve Number method could be able to represent the relationship of rainfall with surface flow (run off) and also to predict runof

Optimasi Pola Tanam Menggunakan Program Linier (Waduk Batu Tegi, DAS Way Sekampung, Lampung)

Waduk Batu Tegi terletak di DAS Way Sekampung,SWS Way Seputih-Way Sekampung, Batu Tegi, Kecamatan Air Naningan, Kabupaten Tanggamus, Lampung. Waduk ini berfungsi sebagai penyedia air untuk irigasi, penyedia air baku, dan Pembangkit Listrik Tenaga Air (PLTA). Dengan keterbatasan volume air yang tersedia di waduk, dilakukan optimasi agar dapat mengoptimalkan kebutuhan air untuk irigasi yang menentukan intensitas tanam suatu lahan, air baku untuk sektor domestik dan non-domestik, dan potensi PLTA. Tujuan dari optimasi pola tanam adalah menentukan harga maksimal hasil panen yang dapat dihasilkan suatu lahan dengan jenis tanaman yang berbeda. Optimasi dalam kasus ini dilakukan dengan menggunakan program linier program bantu Quantity Methods for Windows. Perhitungan optimasi dengan pola tanam rencana dilakukan agar optimasi berupa intensitas tanam menghasilkan panen yang lebih maksimal jika dibandingkan dengan pola tanam eksisting. Dari hasil analisis yang telah dilakukan, didapatkan kesimpulan bahwa debit andalan 80% waduk yang terbesar adalah 76,7 m3/detik yang terjadi pada Bulan Februari dan yang terkecil adah 4,30 m3/detik yang terjadi pada Bulan Oktober, model alternatif pola tanam yang menghasilkan luas lahan dan keuntungan hasil panen paling optimum adalah Alternatif 5, besar kebutuhan air untuk irigasi dari alternatif 5 adalah 346,2 x 10 6 m3dalam satu tahun, besar kebutuhan air untuk air baku saat kondisi jam puncak pada tahun 2010 adalah 27,69 m3 x 10 6 m3 dan kebutuhan air untuk PLTA adalah 734,8 m3 x 10 6 m3, serta keuntungan maksimal yang didapatkan dari hasil produksi lahan sawah dengan menggunakan pola tanam alternatif 5 adalah Rp 1.890.843.057.506,00