PERENCANAAN PEMBANGKIT LISTRIK TENAGA MINI HIDRO (PLTM) TUKAD DAYA KABUPATEN BULELENG � BALI

Electrical energy is a very important necessity in human life today, where almost all human needs associated with electricity. PLTM present as a micro power plant with abundant resources and low maintenance costs when compared to electricity generator with other resources. In Buleleng District, Bali Province flows river Tukad Daya which will be planned 2 pieces of turbines. The results of the analysis of hydrologic discharge results with 74% reliability is 1.4 m3 / s. Potential power awakened in turbin 1 is 1878 kW with a height of fall (head) 152 m, and the second turbine produces 2620 kW with a high fall (head) 210 m. PLTM Tukad has 2 sandtrap which have exact same dimension with 90 of length and 5 m of width. It also has 2 headtank which also has the same dimension with 6 m of length and 6 m of width. With the construction of Tukad Daya micro power plant which is at a relatively inaccessible location is expected to help provide electricity supply for the community. As one kind of electrical energy generation with renewable resources, namely water then Tukad Daya micro power plant is very enviromental friendly and does not require significant operational cost Key words: micro power plants, Tukad Daya , Micro power facility ,building dimension

evaluation of forces on steel truss structure using resonance frequency analysis (experimental and numerical study)

Structural decay may be defined as any deviation in a structure�s original geometry or material properties that may cause undesirable stresses, displacements, and vibrations in the structure. This decay may be due to cracks, loose bolts, broken welds, corrosion, or fatigue. In addition, many bridges are decayed due to aging, misuse, lack of repair, and, in some cases, caused by improper design. Conventional inspection remains the most commonly used method for the structural evaluation of bridges. Conventional inspection can be costly and time consuming, especially when disassembly is necessary to provide access to the area being inspected. Nondestructive testing such as resonance frequency analysis provides an alternative solution. Based on literature study carried out on resonance frequency testing for the determination of axial forces, a simple truss structure was modeled. The truss structure has 2 members using equal steel section of L.30.30.3, each acting as a compression and tension members, and then applied load was accomplished by hanging a steel block on the tip of the truss being tested. Finally, transversal frequency measurements were performed on the truss members under various load levels. The collected resonance frequencies were then evaluated using Bernoulli beam theory to estimate member forces and rotational spring parameter at the ends of the member. This research shows that the error of estimation of member forces in compression and tension members using modified natural frequency and rotational spring parameter by linear regression method varies from 0.26% to 1.99% and 0.2% to 2.41% respectively. The value of rotational spring parameters indicates that the members have semi rigid behavior and closer to fixed rather than pinned conditions

PENGARUH �FLUID-STRUCTURE INTERACTION� PADA RESPON DINAMIK STRUKTUR PLATFORM LEPAS PANTAI

Offshore platform structures are considered to be structures having relative more complex and unpredictable environmental action. Vibration of structures in land is certainly different from vibration of structures in ocean. This final project conducted to study about dynamic responses because of platform structure subject to offshore environment. The sea water around structure is modelled as added mass that would effect dynamic parameter of the structure. Structural and environment data were taken from previous final project which had not considered the effect of sea water in the dynamic analysis. Finite element method was employed to analyze the offshore structure by used of Structural Analysis Program (SAP) 2000. Analysis verification was done manually for ensuring the validity of the input data to the program. Analysis of the capacity of the structures and of virtual fixity point of the foundation were also conducted to give some review about existing structure condition. The result of analysis indicated that sea water around the structure reduced the dynamic responses of the structure significantly (RMS value = 58.79 % , for certain wave load, at specific joint and axis). The order of reduction of the structure responses depends on the interaction between sea water and the structure configuration and it would be different in every parts of the structure. For seismic load, analysis result showed that structure submerged in the water had larger displacements than unsubmerged structure (303.60 %, for specific damping ratio, joint and axis) due to the additional inertia forces originated from added mass. Apart from dynamic structure response, location of the virtual fixity point of the foundation turned to be -10 m bellow the mud line from total -150 m foundation depth

ANALISIS DAN PENGUJIAN KEKUATAN KUDA-KUDA BAJA RINGAN PROFIL TIPE C DENGAN BEBAN STATIK

Demand of houses as the main component of society need increases. It gives impact on the increasing of wood demand as one of building materials. The decreasing of wood availibility causes the wood cost that is more expensive. One alternative solution is creating materials that can replace the function of wood. One of them is mild steel, that can be used for trusses. After the 2006 earthquake in Yogyakarta, lots of constructions with mild steel truss had damaged, especially that used ceramic tiles. If compared with wood material, mild steel is easier to be used and saves construction time. Nevertheless, using ceramic tile on mild steel truss is still regarded unappropriate and need of further study. The research was conducted experimentally to two truss specimens of mild steel with different spans, which were 6 m and 8 m, respectively and used ceramic tiles whose weight was 43.4 kg/m2 as dead load. This weight was heavier than concrete tiles with weight of 40 kg/m2. The experimental testing of the truss was done by applying static load with gradual loading. As verification, a global analysis of Finite Element Method using SAP 2000 computer program was done upon the truss and the failure criteria of Von-Mises was adopted. The test result on the 6 m span truss specimen is described as follows. The maximumload planned was 343% from the total weight of the truss roof-tile with space of 1.2 m and was fulfilled. On the other hand, on the 8 m span specimen there was damage while increasing the sand load up to about 180% of roof-tile total load. It was due to the mistake in mounting bolts onto the pedestal of one of the easels. The displacement of LVDT 1 on the middle span when the maximum load for the 8 m span specimen was 16.25 mm from the result of experiment and 2.476 mm from the result of FEM analysis.Meanwhile, for 6 m span truss it was 9.55 mm from the result of experiment and 3.513 mm from the result of FEM analysis. The result of FEM analysis and failure theory of Von-Mises on the detail analysis of one of pedestals showed that there was failure in some areas which agree well with the result of experiment

SIMULASI NUMERIK PERILAKU BENDUNGAN KEDUNG OMBO PADA BEBAN SEISMIK

Dynamic simulation with finite element method (FEM) was conducted to predict the response of dams to input a particular earthquake, with more rigorous. This response needed to predict the response of the dam in assessment stage or in the design stage. Dynamic parameter in assessment stage may not available for dynamic simulation with FEM. The proposed of this thesis is to develop signal similarity method to estimate the value of the dynamic parameter. Dynamic simulation with FEM has done for Kedung Ombo dam. Signal input acceleration time history as a result of the recorded Strong Motion Accelerograf (SMA) set on Kedung Ombo dam. Adjustment effort carried on signal acceleration time history to remove nonstandard errors and standard noise. Dynamic simulation performed with a linear elastic model. Dynamic parameter value is obtained by selecting a value in the range of dynamic parameters. The range of dynamic parameters searched with an empirical correlation, where the dynamic parameter is the dynamic shear modulus and damping ratio. Dynamic simulation carried out with 165 variations in the treatment of the range dynamic parameter values. One of 165 treatments has been chosen for the dynamic parameter value on the dynamic FEM simulation. Selection of dynamic parameters based on the similarity of time domain and frequency domain of the signal SMA. The simulation results show that a linear elastic dynamic model and parameters chosen are available to imitate the acceleration time history recorded SMA at the level of certain shear strain. Dynamic parameters soil and foundation resulting from the similarity of time and frequency domain produce value at the appropriate reasonable range. Dynamic simulations also done to study the response of Kedung Ombo dam on Yogya quake in May 2006 based on dynamic parameters that already found. Based on the simulation, amplificaton of peak acceleration on the crest of the dam occurred in the amount of 2,138. The simulation results showed no liquefaction occurred at this dam accordance with the real condition. Dynamic simulation also available to be applied for study the response of dams elsewhere by knowing the recording of the acceleration time history at the dam foundation. The fundamental frequency of Kedung Ombo dam also counted using amplification spectra and FEM. The result of the fundamental frequency with the FEM calculation is 0.773 Hz. Amplification spectra result dominant frequency value that are 0.829 Hz, 1.584 Hz, 1.75 Hz, where the upstream reservoir at EL. 80.26 m. While the results of FEM have mode 1, 2 and 3 in a row on the value of 0.773 Hz, 1.171 Hz and 1.505 Hz

MECHANICAL PROPERTIES DAN PERILAKU CREEP DAN SHRINKAGE BETON MUTU TINGGI USIA MUDA

Development in the field of structure has undergone highly rapid progression with the increasing number of suprastructures, which are and will be built by human, such as high-story building construction, bridge, structure in water, anti-nuclear radiation building, and so on. To meet the need for the quality structures, concretes must have high strength. Such concretes are usually designed for the structures of highway, bridge, building, sea building, and port. In addition to advantages, they have also disadvantages: they can shrink and swell, brittle (not ductail), and with low tensile strength. Due to load and environmental effect, the concretes can show creep and shrinkage phenomenon. creep and shrinkage in the concretes of early age are two factors that can influence the premature cracks of concretes and also affect the durability and performance of structures in the high strength concrete at early age. This study on the mechanical properties and creep and shrinkage behaviors in the high strength concretes at early age used three types of the tested Specimens, i.e. 10 cylinders of 150 mm x 300 mm in size, 5 prisms of 76 mm x 76 mm x 286 mm in size, and 6 cubes of 150 mm x 150 mm dan 150 mm in size. The ratio of mix determined was 1 variation and the additional material of Superplasticizer Sika ViscoFlow 3211N, using the fas of 0.32 and the slump of 20 cm. The objective of the study is to find out compresive strength, elastisity modulus, creep and shrinkage in the concretes of the early age. The results of the study show that the compressive strength value of concretes with the tested objects of cylinders of 1, 2, 4, and 28 days old were 22.94 MPa, 33.39 MPa, 43.01 Mpa, and 56.72 MPa, respectively. Meanwhile, the compressive strength value of concretes with creep that were tested again at 28 days old was 54.04 MPa. The compressive strength value of concrete with the tested object of cubes at 1, 4 and 28 days old were 288.90 kg/cm2 (28.89 MPa), 421 kg/ cm2 (42.10 MPa), and 526.63 kg/cm2 (52.63 MPa), respectively. The elastisity modulus value of concretes with the tested specimens of cylender at 2 days old were 35280.28 MPa and 25709.09 MPa. The high tense value of creep in the tested specimen of HSCCreep 28.1 was 0.000154, while the lowest tense value of creep in the tested spemen of HSCCreep 28.2 was 0.000880. The high tense value of shrinkage in the tested object of S5 was 0.000367, while the lowest in the tested object of S1 was 0.000035