1. Abstract In many cases prestressed concrete structures are more advantages than ordinary reinf... more 1. Abstract In many cases prestressed concrete structures are more advantages than ordinary reinforced concrete structures. However, designing prestressed concrete structures that fulfil the optimum criteria is not an easy task. This is because there is an interaction between the size of cross sections and prestressing force that has to be given to the structures. Optimization of prestressed concrete structures becomes a challenging task for most structural designers. This paper considers optimization procedures for prestressed concrete beams. For obtaining prestressing force, the moment coefficient method, which is the ratio of moment due to prestressing force divided by prestressing force, is used in the computation. In statically determinate structures this coefficient exactly is the eccentricity between center of gravity of the section and the center of gravity of the prestressing steel. However, in statically indeterminate structures, this ratio is not the same as the eccentric...
: Four stories building was used as structure model. Static earthquake loads distribution were de... more : Four stories building was used as structure model. Static earthquake loads distribution were determined according to SNI 1726:2012. The effect of dynamic earthquake loads also considered. The result of structural analysis determined using ETABS. It were static shear force 1.082,64 KN and dynamic shear force, Fx = 1.057 KN and Fy = 983,5 KN. Colomn and beam forces were also determined. Support reactions and joint displacements were determined through structural analysis. Mass modal participation has been reached over 90% at mode 5. Story drift was still smaller than the allowable story drift.Keywords : earthquake loads analysis, residential building.Abstrak:Model struktur yang dianalisis yaitu gedung beraturan lantai 4 untuk rumah tinggal. Distribusi beban gempa statik diperoleh sesuai dengan SNI 1726:2012. Pengaruh beban gempa dinamik juga diperhitungkan. Hasil analisis struktur diperoleh antara lain besaran gaya geser statik 1.082,64 KN dan gaya geser dinamik, Fx = 1.057 KN dan F...
Beton prategang berbeda dengan beton bertulang biasa karena mempunyai keunikan dalam penentuan te... more Beton prategang berbeda dengan beton bertulang biasa karena mempunyai keunikan dalam penentuan tegangan ijin karena harus memenuhi dua tahapan pembebanan. Penentuan gaya prategang menggunakan metode koefisien momen β yang didasarkan pada tegangan ijin. Pada metode ini, akan diperoleh batas atas dan batas bawah nilai gaya prategang. Algoritma genetika merupakan metode pencarian sesuai dengan proses genetika organisme berdasarkan teori Darwin. Dalam penelitian ini, digunakan algoritma genetika real untuk menentukan variabel yang optimum beton prategang pada balok sederhana dan menerus dengan penampang persegi dan T berdasarkan rentang nilai gaya prategang. Variabel yang dioptimasi adalah ukuran penampang (persegi dan T) dengan meminimumkan total harga struktur. Hasil optimasi yang diperoleh adalah ukuran penampang dan total harga dipengaruhi oleh nilai gaya prategang yang digunakan untuk menentukan fungsi fitness. Total harga maksimum diperoleh jika nilai gaya prategang yang digunakan...
Model struktur yang dianalisis yaitu gedung beraturan lantai 4 untuk rumah tinggal. Distribusi be... more Model struktur yang dianalisis yaitu gedung beraturan lantai 4 untuk rumah tinggal. Distribusi beban gempa statik diperoleh sesuai dengan SNI 1726:2012. Pengaruh beban gempa dinamik juga diperhitungkan. Hasil analisis struktur diperoleh antara lain besaran gaya geser statik 1.082,64 KN dan gaya geser dinamik, Fx = 1.057 KN dan Fy = 983,5 KN. Besaran gaya elemen kolom dan balok juga diperoleh. Reaksi tumpuan serta perpindahan titik buhul dapat diketahui dari hasil analisis yang dilakukan. Pada mode 5, partisipasi massa model yang dianalisis sudah mencapai >90%. Simpangan antar lantai yang terjadi pada model struktur tidak melebihi simpangan yang diijinkan.
Four stories building was used as structure model. Static earthquake loads distribution were dete... more Four stories building was used as structure model. Static earthquake loads distribution were determined according to SNI 1726:2012. The effect of dynamic earthquake loads also considered. The result of structural analysis determined using ETABS. It were static shear force 1.082,64 KN and dynamic shear force, Fx = 1.057 KN and Fy = 983,5 KN. Colomn and beam forces were also determined. Support reactions and joint displacements were determined through structural analysis. Mass modal participation has been reached over 90% at mode 5. Story drift was still smaller than the allowable story drift.
The effect of earthquake loads have to be considered when we need to design a building in Indones... more The effect of earthquake loads have to be considered when we need to design a building in Indonesia because of the earthquake happen almost on every region in Indonesia. This study mean to achieve slab design. Four stories building in Gunungsitoli city used as structure model. Slab has been design as one way slab. Loads considered in SNI 1727:2013, while the design process according to SNI 2847:2013. From this study, the dimension of roof slab is 10 cm, while reinforced are Ø10-200 and Ø8-200. The dimension of floor slab is 12 cm, while reinforced are Ø10-200 and Ø8-150.
Structural design philosophy expected to be low cost and safe at once. At prestressed concrete st... more Structural design philosophy expected to be low cost and safe at once. At prestressed concrete structure, concrete allowable stress for bending structural component have to fullfill limit values on tranfer and service condition. Prestressed force determined using moment coeffiecient β method based on allwoable stress. At this structure, to achieve optimum design is not an easy task due to interaction between dimension size and prestressing force value. To determine optimum design criteria, genetics algorithms as one of optimum design method has been used in this paper. Genetics algorithm is a method to find the best solution using organism genetics process based on Darwin theory which solutions with the best fitness value that could be survive as the optimization result. Fitness value is minimum construction cost. Optimization process using genetics algorithm has been worked with computer software assitance Matlab. Simpe beam has been considered as numerical example. Optimization result is optimum design of dimension size and prestressing force. Optimization procedure with beam length (L) 10 m result are beam width (b) 0,40 m, beam height (h) 0,47 m, prestressing force (Fi) value 1344 KN and bulding cost total Rp. 16.651.000,-. Next optimization procedure has been done using different beam length. From this study, the interaction between beam length to optimum dimension size and minimum building cost has been achieved.
1. Abstract In many cases prestressed concrete structures are more advantages than ordinary reinf... more 1. Abstract In many cases prestressed concrete structures are more advantages than ordinary reinforced concrete structures. However, designing prestressed concrete structures that fulfil the optimum criteria is not an easy task. This is because there is an interaction between the size of cross sections and prestressing force that has to be given to the structures. Optimization of prestressed concrete structures becomes a challenging task for most structural designers. This paper considers optimization procedures for prestressed concrete beams. For obtaining prestressing force, the moment coefficient method, which is the ratio of moment due to prestressing force divided by prestressing force, is used in the computation. In statically determinate structures this coefficient exactly is the eccentricity between center of gravity of the section and the center of gravity of the prestressing steel. However, in statically indeterminate structures, this ratio is not the same as the eccentric...
: Four stories building was used as structure model. Static earthquake loads distribution were de... more : Four stories building was used as structure model. Static earthquake loads distribution were determined according to SNI 1726:2012. The effect of dynamic earthquake loads also considered. The result of structural analysis determined using ETABS. It were static shear force 1.082,64 KN and dynamic shear force, Fx = 1.057 KN and Fy = 983,5 KN. Colomn and beam forces were also determined. Support reactions and joint displacements were determined through structural analysis. Mass modal participation has been reached over 90% at mode 5. Story drift was still smaller than the allowable story drift.Keywords : earthquake loads analysis, residential building.Abstrak:Model struktur yang dianalisis yaitu gedung beraturan lantai 4 untuk rumah tinggal. Distribusi beban gempa statik diperoleh sesuai dengan SNI 1726:2012. Pengaruh beban gempa dinamik juga diperhitungkan. Hasil analisis struktur diperoleh antara lain besaran gaya geser statik 1.082,64 KN dan gaya geser dinamik, Fx = 1.057 KN dan F...
Beton prategang berbeda dengan beton bertulang biasa karena mempunyai keunikan dalam penentuan te... more Beton prategang berbeda dengan beton bertulang biasa karena mempunyai keunikan dalam penentuan tegangan ijin karena harus memenuhi dua tahapan pembebanan. Penentuan gaya prategang menggunakan metode koefisien momen β yang didasarkan pada tegangan ijin. Pada metode ini, akan diperoleh batas atas dan batas bawah nilai gaya prategang. Algoritma genetika merupakan metode pencarian sesuai dengan proses genetika organisme berdasarkan teori Darwin. Dalam penelitian ini, digunakan algoritma genetika real untuk menentukan variabel yang optimum beton prategang pada balok sederhana dan menerus dengan penampang persegi dan T berdasarkan rentang nilai gaya prategang. Variabel yang dioptimasi adalah ukuran penampang (persegi dan T) dengan meminimumkan total harga struktur. Hasil optimasi yang diperoleh adalah ukuran penampang dan total harga dipengaruhi oleh nilai gaya prategang yang digunakan untuk menentukan fungsi fitness. Total harga maksimum diperoleh jika nilai gaya prategang yang digunakan...
Model struktur yang dianalisis yaitu gedung beraturan lantai 4 untuk rumah tinggal. Distribusi be... more Model struktur yang dianalisis yaitu gedung beraturan lantai 4 untuk rumah tinggal. Distribusi beban gempa statik diperoleh sesuai dengan SNI 1726:2012. Pengaruh beban gempa dinamik juga diperhitungkan. Hasil analisis struktur diperoleh antara lain besaran gaya geser statik 1.082,64 KN dan gaya geser dinamik, Fx = 1.057 KN dan Fy = 983,5 KN. Besaran gaya elemen kolom dan balok juga diperoleh. Reaksi tumpuan serta perpindahan titik buhul dapat diketahui dari hasil analisis yang dilakukan. Pada mode 5, partisipasi massa model yang dianalisis sudah mencapai >90%. Simpangan antar lantai yang terjadi pada model struktur tidak melebihi simpangan yang diijinkan.
Four stories building was used as structure model. Static earthquake loads distribution were dete... more Four stories building was used as structure model. Static earthquake loads distribution were determined according to SNI 1726:2012. The effect of dynamic earthquake loads also considered. The result of structural analysis determined using ETABS. It were static shear force 1.082,64 KN and dynamic shear force, Fx = 1.057 KN and Fy = 983,5 KN. Colomn and beam forces were also determined. Support reactions and joint displacements were determined through structural analysis. Mass modal participation has been reached over 90% at mode 5. Story drift was still smaller than the allowable story drift.
The effect of earthquake loads have to be considered when we need to design a building in Indones... more The effect of earthquake loads have to be considered when we need to design a building in Indonesia because of the earthquake happen almost on every region in Indonesia. This study mean to achieve slab design. Four stories building in Gunungsitoli city used as structure model. Slab has been design as one way slab. Loads considered in SNI 1727:2013, while the design process according to SNI 2847:2013. From this study, the dimension of roof slab is 10 cm, while reinforced are Ø10-200 and Ø8-200. The dimension of floor slab is 12 cm, while reinforced are Ø10-200 and Ø8-150.
Structural design philosophy expected to be low cost and safe at once. At prestressed concrete st... more Structural design philosophy expected to be low cost and safe at once. At prestressed concrete structure, concrete allowable stress for bending structural component have to fullfill limit values on tranfer and service condition. Prestressed force determined using moment coeffiecient β method based on allwoable stress. At this structure, to achieve optimum design is not an easy task due to interaction between dimension size and prestressing force value. To determine optimum design criteria, genetics algorithms as one of optimum design method has been used in this paper. Genetics algorithm is a method to find the best solution using organism genetics process based on Darwin theory which solutions with the best fitness value that could be survive as the optimization result. Fitness value is minimum construction cost. Optimization process using genetics algorithm has been worked with computer software assitance Matlab. Simpe beam has been considered as numerical example. Optimization result is optimum design of dimension size and prestressing force. Optimization procedure with beam length (L) 10 m result are beam width (b) 0,40 m, beam height (h) 0,47 m, prestressing force (Fi) value 1344 KN and bulding cost total Rp. 16.651.000,-. Next optimization procedure has been done using different beam length. From this study, the interaction between beam length to optimum dimension size and minimum building cost has been achieved.
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