Applied Mechanics and Materials Vol. 776

Abstract: This paper investigated to what extend risk analyses may play its role in the development of feasibility study of Riau regional water supply projects (regional SPAM). This SPAM services coverage area may cover 4 (four) regions in Riau province such as; Rokan Hulu regency, Rokan Hilir, Bengkalis and Dumai. The capacity of this SPAM is 500 l/second. Total financing required for development of this SPAM was approximately Rp. 344 billion. Project finance will be obtained from budget sharing scheme from APBN (Rp. 140 billion or 41%), APBD (Rp. 62 billion or 18%), and the private sector (Rp. 141 billion or 41%). Three stages of risk analyses have been applied in this paper, such as; (i) risk identification, (ii) risk assessment, and (iii) risk mitigation. Based on the simulation result, it was identified that the initial project NPV was in the rage of-Rp. 6.68 billion up to Rp. 18.01 billion. The mean value of the projected NPV was Rp. 6.27 billion. This project is considered to be risky to proceed, as there is 90% probability the projected NPV < Rp. 0. After risk mitigation procedure will be applied, there is a mean value of the project NPV is Rp. 9.9 billion (increase by 30% from the initial NPV). Four significant risk variables affected NPV performance are identified as follow; (i) engineering cost for constructing water treatment plant and facilities, (ii) cost of pipelines installation and accessories, (ii) electricity costs, and (iv) chemical cost expenditure. A reduction of technical uncertainties including design changes; redundant of engineering risk costs, introduction of energy efficient technology during project operation may reduce electricity and chemical costs. Hence, based on the simulation results, it is confirmed that, the risk analyses procedure may improve regional SPAM regional technical and economy performances (e.i. NPV parameters).

Abstract: The purpose of this research is to create a model of the discharge as the impact of climate change due to global warming. The study was conducted using data from the Bangga watershed. Monthly water balance model used is the development of a model FJ. Mock by entering the natural phenomena that occur at this time such as climate change, canopy interception, rainfall distribution based on land use, soil type and soil characteristics. Calibration of water balance is used to determine the performance of the models to variations in climate change. Then, analysis is conducted as the effect of rain and temperature on runoff at river Bangga. The conclusion of this research were: 1) Accuracy of discharge simulation models against observed discharge is quite good, which is characterized by the Nash coefficient (Ns) close to one except for a few periods and annual rainfall runoff ratio (RE) approaches one. 2) Changes in rainfall have a considerable influence on the runoff, while the effect of temperature on runoff is not too significant.

Abstract: s. Management of water for irrigation in Bali has been exist since the IX century, which is known as Subak. Subak is traditional irrigation system and it is closely associated with the principle of Tri Hita Karana. The elements and facilities of subak include: irrigation networks, organizational structures and regulation. Distribution of water uses a comparison unit called ayahan. One unit of ayahan entitled to one tektek or one kecoran which is a unit of water flowing through the cross section of traditional spillway on a countinuous basis. If water availability is limited, then water supply is managed by rotation basis called pergiliran or nyorog system that based on different planting time. The principle of nyorog is the upstream section get water first (called ngulu), the midstream obtain water after the upstream had finished cultivating of soil (called maongin), and the downstream called ngasep. In rainy season, rice planting is simultaneously done in all area of subak, which is called kertamasa. Meanwhile in dry season called gadon, rice planting is scheduled by principles of nyorog or rotation. The arrangements of water resources and the settings of cropping pattern is stated in regulation (awig awig). Water distribution were managed ​​by the administrators of subak within the territory, or through an agreement between the territories’ administrators. The Sedahan and Sedahan Agung, whom in charge as subak’s adviser have very important role in the coordination on management and use of water. Recently they are facing uncertainty in existence, and causing lost of coordination in resolving various problems. In the future, the functioning of the Sedahan and Sedahan Agung is needed.

Abstract: Beach nourishment, or also commonly known as beach fill, is a technique widely used in coastal engineering to rehabilitate eroded beaches or create new beaches and widen existing beaches. However, once an instance of beach filling has occurred, it needs to be repeated on a regular basis because the new beach would be more prone to abrasion than natural beaches. This paper describes the of beach change based on numerical modeling in the study of the evolution of a beach nourishment project. The measured beach profile, wave height and sediment in Sanur beach, Bali are used for the numerical analysis based on the existing studies are applied in the analysis of the beach. The simulation results show that there are three segment of the coastal area in between the groin need to be overcome.

Abstract: Smoothed Particle Hydrodynamic (SPH) numerical model is used to investigate wave group effects at breaking and after breaking by comparing individual waves in a group with equivalent regular waves. Regular wave break almost at the same position and with the same wave height. Meanwhile in a wave group, the wave breaks in the variant positions and with variant wave heights. These phenomena cause the breaking point to be more scattered in a wave group rather than in regular waves. Return flow due to the breaking of wave groups appears more significant and is extended to the full depth in the surf zone rather than in regular waves. Swash oscillations of the wave group in the surf zone appear irregular. Meanwhile in regular waves, swash oscillations are almost constant.

Abstract: The foundation of the reinforced concrete arch bridge beams of Tukad Pekerisan and Tukad Penet (Pekerisan River and Penet River) Bali, were first designed to use well foundation on a rock soil adapted to the boring results. However, at the time of excavation, the base soil was founded to have textures that contain of both longitudinal and transverse cracks. The fractures were found to form a rectangular pattern and continued down to the layer of soil. It was feared that the slope will not be strong enough and could collapse. The purpose of this study is to determine the strength and stability of the bore piles foundations of reinforced concrete arch bridge, in order to avoid the possible collapse of the banks on the bridge foundation. The alternative of bore piles as underpinning were selected by considering the field problems, such as the elongated soil crack sand a very steep slope of soil near the construction.

Abstract: This paper is to propose a concept of boundary line onBali coastal tourist resorts in which the aim of this concept is to offer aclear boundary between private owners and public space and to avoid dispute on the land ownership between privates and the state. The rationale behind this concept is because there isa serious problem in these areas resulted from many interests and activities being in conflict as result they become a very sensitive space. Beach utilisation without planning, takes place creatinga conflict of interest which tends to bringnegative impacts on social, economic, politic and environmental aspect.According to research, the areais impacted upon by physical problemsemerging not only from the offshore but also the onshore sources. If there is no solution immediately, it will bring serious implication for social and environmental cost which will adversely affect all parties and Bali as a whole. Therefore, the boundary line concept is expected to be one of the most effective solutions to solve the problem, and in turn it becomesamodel to sustain the areas as the most popular tourist attractions in Bali.

Abstract: House is one of the most basic needs of human life other than food and clothing. House comfort can be studied in house ergonomic. In House Ergonomic, research of the various factors that can be called decent house would have to meet the criteria of ergonomic house. Indonesia is a country with many different cultures, each of which has a typical traditional house for the region. In the days before globalization began, people of Indonesia had to build their own houses. The traditional house of the culture diversity is constructed without researching the science of ergonomics and modern architecture in theory, but is built from traditional local knowledge based on the philosophy and beliefs.

Abstract: Natural fiber reinforced composites material are used in more and more industries for their low cost, lightweight, and more importantly, the properties of friendship to environment. Environmental friendship is a very significant superiority of natural fiber composites for auto industry. In this paper, the following aspects are reviewed: (1) superiority of natural fiber reinforced composite materials to glass fiber reinforced composite material, especially when they are used in automobile industry; (2) current usage in automobile industry and the prospective in the future; (3) recent developments.

Abstract: This paper investigated the fracture behavior of the unavoidable breakage of carbon fibers and fiber orientation of short carbon fiber reinforced polycarbonate composite in injection process. In this experiment, short carbon fiber mixed compound of 1mm, 3mm, 5mm, 7mm length with 10wt.%, 15wt.%, 20wt.% in polycarbonate for injection molding were produced through the extruder. The dumbbell specimens for tensile evaluation were made by injection molding. The parent specimens were made by double gate method, the weld specimens were made by single gate method which was controlled by inserting a stopper through the runner of the mold cavity. Short carbon fiber reinforced PC composite was evaluated by micro-CT with regard to the particle size of short fiber with a diversified quantitative analysis through entire process of the injection process in composite. The quantitative distribution of fiber orientation was also examined by micro-CT with regard to normal direction or anisotropy. Weld line of short carbon fibers reinforced PC composite weaken the bonding strength by 50% compared to parent materials because the weld line is composed with concentrated anisotropy orientation of short carbon fiber in weld line. Evaluation of the mechanical properties of the injection specimens group was utilized by universal tensile strength tester. In addition, fracture surface of parent and weld materials was investigated by a SEM.