Seismic reliability assessment of a non-seismic reinforced concrete framed structure designed according to ABNT NBR 6118:2014

abstract: Due to the paucity of studies regarding the seismic assessment of buildings in Brazil, this study aims to present and discuss a seismic reliability assessment of a reinforced concrete framed structure designed according to the Brazilian standard ABNT NBR 6118:2014 without the consideration of the seismic design requirements of ABNT NBR 15421:2006. Herein, fragility functions are generated through probabilistic seismic demand analysis, and integrated with hazard curves for Northeastern Brazil to generate regional failure probability maps for three limit-states: Immediate Occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). The results indicated that the building performance is adequate for IO; however, for LS and CP, an unacceptable performance is observed.

Evaluasi Struktur Bangunan Pasar Inpress Blok IV Gedung B dengan Metode Pushover

Inpres market block IV Pasar Raya Padang is not designed as a shelter building, but is designated as a vertical evacuation site when a tsunami occurs. This study aims to evaluate the structural performance of Inpress market block IV zone B. The method used for this research is the pushover analysis method. According to FEMA P-646/2019, vertical evacuation refuge structures are included in tsunami risk category IV, based on the risk category the maximum performance level is at the Immediate Occupancy (IO). For loads on buildings, refer to SNI 1727:2020 and SNI 1726:2019 for earthquake loads. For the calculation of the capacity of concrete structural elements, refer to SNI 2847:2019. Structural analysis was carried out using the SAP2000 version 16. After analysis, based on performance points, drift ratio that occur due to earthquake loading in X-direction and Y-direction are 0,05875% and 0,0067%. The maximum total drift that occurs is smaller than that required by ATC-40 for the Immediate Occupancy performance level, which is 1%. Thus, the structure performance level is Immediate Occupancy. This means that the Inpress market block IV building is still strong enough against earthquake loads.

Analisis Pushover terhadap Variasi Penempatan High Damping Rubber Bearing (HDRB) pada Struktur Gedung Bertingkat

High Damping Rubber Bearing (HDRB) merupakan salah satu jenis isolator yang digunakan dalam perancangan struktur gedung tahan gempa, biasanya ditempatkan pada dasar bangunan dan berfungsi untuk meredam gaya gempa. Penelitian ini bertujuan untuk mengetahui respon struktur berupa gaya geser dasar dan simpangan antar lantai, serta tingkat kinerja struktur gedung bertingkat terhadap variasi penempatan HDRB menggunakan metode analisis pushover dengan bantuan software ETABS. Struktur gedung beton bertulang 12 lantai, dengan tinggi tiap lantai 4 m. Variasi penempatan HDRB pada model 1 di dasar gedung, pada model 2 di lantai pertama dan pada model 3 di tengah-tengah gedung. Standar analisis mengacu pada SNI 1726:2019 dan ATC-40. Hasil penelitian menunjukkan bahwa gaya geser dasar maksimum yang paling menentukan dari ketiga model struktur gedung bertingkat yang terbesar, yaitu 2.566,78 kN dengan perpindahan maksimum 0,35 m. Tingkat kinerja berdasarkan ATC-40 termasuk dalam kategori aman yaitu Immediate Occupancy (IO). Berdasarkan SNI 1726:2019 memenuhi batasan simpangan antar lantai izin.

Analisis Kinerja Struktur Pada Model Bangunan Setback Menggunakan Metode Time History Analysis

Bencana gempa bumi dapat menelan banyak korban jiwa. Oleh karena itu desain bangunan tahan gempa sudah menjadi kewajiban dalam merancang suatu bangunan sebagai antisipasi apabila terjadi gempa bumi.Penelitian ini bertujuan untuk mengetahui level kinerja dari sistem struktur setback dan sistem struktur non setback menggunakan metode time history analysis. Terdapat 3 model struktur yang dikaji yaitu struktur non setback dengan sistem struktur 6 lantai, dimana bentang terpanjang 20 m, bentang terpendek 15 m, dan tinggi setiap lantai 3,5 m, Sedangkan model setback1, setback di aplikasikan pada lantai 6 dan model setback2, setback diaplikasikan pada lantai 5 dan lantai 6. Hasil penelitian ini menunjukan kapasitas penahan gempa lateral terbesar adalah bangunan setback satu lantai pada arah x (timur-barat), dengan perbedaan sebesar 1,07%, sedangkan pada arah y (utara-selatan) kapasitas penahan gempa terbesar adalah bangunan non setback, dengan perbedaan sebesar 4,79%. Level kinerja struktur yang dihasilkan dari bangunan setback dan non setback bervariasi, dari immediate occupancy sampai damage control.

Analisis Kinerja Struktur Rangka Beton Bertulang Beraturan Dengan Penambahan Tingkat Menggunakan Struktur Baja

The change of plans on gradually development in building structure can be occur with building operational consideration and owner financial. The purpose of this study was to determine the level of performance of the reinforced concrete frame structure with additional levels using steel structures with different span variations. The results of the analysis are used to determine how big the deviation is between levels and to control the level of structure performance. The conclusion of the study shows that the performance level of the structural model analyzed is immediate occupancy (IO) with a total drift ratio and interstorey drift ratio value of the initial building structure (C3S0) in the x direction and y direction of 0.0004, and for variations in building structure with the addition of levels using steel structures (C3S1, C3S2, C5S1, C5S2, C7S1, C7S2) in the x direction ranging from 0.0005-0.0007 and in the y direction ranging from 0.0010-0.0024.

KINERJA STRUKTUR BANGUNAN CANDI SIWA MENGGUNAKAN METODE ANALISIS RESPONSE SPECTRUM DAN TIME HISTORY

Candi Siwa merupakan salah satu candi yang terdapat di kompleks Candi Prambanan yang terletak di perbatasan Yogyakarta dan Jawa Tengah. Candi Siwa mengalami kerusakan akibat gempa pada tahun 2006, setelahnya dilakukan kegiatan rehabilitasi pada Candi Siwa berupa perkuatan kolom, balok dan pelat beton bertulang. Adanya perkuatan yang diberikan pada Candi Siwa, maka perlu diketahui bagaimana kekuatan struktur tersebut apabila diberi beban gempa. Pada penelitian ini menggunakan analisis response spectrum dan analisis time history. Pembebanan yang diberikan dalam analisis mengacu pada SNI 1726:2019 dan SNI 1727:2013. Berdasarkan hasil analisis menggunakan program bantu, didapatkan nilai base shear adalah 38213,296 ton. Displacement arah X terbesar terjadi pada Undak IV sebesar 39,54 mm dan displacement terbesar arah Y terjadi pada Undak IV sebesar 25,6 mm. Nilai drift maksimum yang terjadi pada Candi Siwa, pada arah X sebesar 0,00459 m pada Kaki I, sedangkan pada arah Y sebesar 0,00551 m terjadi pada Kaki I. Untuk level kinerja struktur Candi Siwa berdasarkan nilai drift ratio pada arah X dan arah Y masing-masing bernilai 0,0011 m dan 0,0007 m, nilai tersebut masuk ke dalam kategori Immediate Occupancy, yaitu kinerja yang umum digunakan dengan tingkat kerusakan yang sangat minim, risiko korban jiwa manusia yang sangat kecil, dan bangunan diharapkan mampu digunakan kembali.

EVALUASI LEVEL KINERJA GEDUNG 6 LANTAI DENGAN METODE NON-LINEAR TIME HISTORY ANALYSIS

Indonesia is a ring of fire area where earthquakes frequently occur. By realizing this, buildings in Indonesia need to calculate earthquake loads based on SNI 03-1726-2019 to minimize victims due to building collapse when earthquakes occur.It is also necessary to evaluate the performance level of a building, in this case a 6-storey building located in the Malang area. For determining the level of performance, a method called Non-Linear Time History Analysis is used. In this calculation used San Fernando, Kobe and Landers ground motion.Based on the results from the evaluation using the Non-Linear Time History method got the maximum drift story 0.137 m that occurs in Kobe ground motion. So that the maximum total drift Dt / H is 0.137 / 21.95 = 0.0063 <0.01. Based on these results, the building performance level includes IO (Immediate Occupancy). AbstrakIndonesia termasuk daerah ring of fire dimana suatu daerah yang sering terjadi gempa. Dengan menyadari hal tersebut, bangunan-bangunan yang ada di Indonesia perlu memperhitungkan beban gempa yang ada berdasarkan SNI 03-1726-2019 untuk meminimalisir korban akibat keruntuhan bangungan yang terjadi akibat gempa. Karena itu perlu juga untuk mengevaluasi level kinerja suatu gedung dalam hal ini gedung 6 lantai yang terletak di daerah Malang. Pada gedung ini untuk dapat diketahui level kinerjanya, maka, digunakan metode yang bernama Non-Linear Time History Analisis. Ground motion yang dipakai adalah San Fernando, Kobe dan LandersBerdasarkan hasil yang diperoleh dari evaluasi dengan metode Non-Linear Time History Analisis ini adalah maximum drift story terbesar adalah 0,137 m yang terjadi pada ground motion Kobe. Sehingga Maximum total driftnya Dt/H adalah 0,137/21,95 =0,0063<0,01. Berdasar hasil tersebut lever kinerja gedung termasuk IO (Immediate Occupancy).

Studi Perbandingan Kinerja Sistem Struktur Setback berdasarkan Metode ATC 40, FEMA 356 dan SNI 1726:2012

The aim of this study was to compare the performance level of the setback structure system and the non-setback structural system using the ATC-40, FEMA 356 and SNI 1726-2012 methods. The non-setback structure have the shortest span of 15 m, the longest span of 20 m and the level of each floor was 3.5 m but the setback structure have setback system on the longest span of 10 m at the 5th and 6th floor level. The results showed that the performance level based on all methods of the sectback structure system is at the immediate occupancy level while the non-setback structure system, based on SNI 1726-2012, the performance level is immediate occupancy for the longest span and the shortest span is damage control. On the other hand, based on the ATC-40 and FEMA 356 methods, the performance level of the non-setback structure is at the immediate occupancy level. Drift on non-setback buildings based on the SNI 1726-2012 method is 0.011, based on the ATC-40 method is 0.007, and based on FEMA 356 is 0.005. Drift on the setback building based on the SNI 1726-2012 method is 0.010, based on the ATC-40 method is 0.006, and based on FEMA 356 is 0.004.

Analisis Kinerja Bangunan Rangka Baja dengan Bresing Tahan Tekuk terhadap Beban Gempa

ABSTRAKPenggunaan bresing tahan tekuk dapat menjadi solusi atas kebutuhan struktur tahan gempa di Indonesia. Disipasi energi pada elemen bresing tahan tekuk dilakukan melalui kinerja plastifikasi bagian inti bresing akibat beban tarik dan tekan. Penelitian ini berisi kajian kinerja dari bangunan rangka baja beraturan dengan bresing tahan tekuk (BRB) dengan variasi level ketinggian lantai yaitu 3 lantai, 8 lantai dan 15 lantai. Analisis struktur 3D dilakukan dengan dua prosedur analisis yaitu modal pushover dan nonlinear time history pada program ETABS. Hasil analisis menunjukkan bahwa pemilihan elemen BRB sangat mempengaruhi kinerja struktur, yang terlihat dari pola drift yang terjadi. Untuk struktur beraturan dengan berbagai ketinggian, tingkat kinerja struktur dengan BRB cukup baik, yaitu Immediate Occupancy (IO) akibat beban gempa rencana. Plastifikasi hanya terjadi pada BRB, dan kelelehan pada balok mulai terbentuk sampai mekanisme keruntuhan terjadi. Hasil modal pushover dengan nonlinear time history pada bangunan 15 lantai yang cukup mirip menunjukkan bahwa modal pushover dapat digunakan untuk memprediksi kinerja struktur BRB yang beraturan.Kata kunci: kinerja struktur, bresing tahan tekuk, immediate occupancy, modal pushover, nonlinear time history ABSTRACTBuckling restrained braces (BRB) can be an alternative solution for earthquake resistant steel structure in Indonesia. The energy dissipation for buckling restrained elements is conducted through yielding of the core due to tension or compression forces. This study presents an evaluation of the structural performance of steel structures with BRB varying in heights, 3-story, 8-story and 15-story. The 3D structural analysis was carried out with ETABS software using 2 methods, Modal Pushover and Nonlinear Time History. The results shows that the selection of BRB elements greatly affected the structural performance, showed by the drift pattern. For regular structures with variation in heights, structures with BRB behaved satisfactory under the design load with the performance level of Immediate Occupancy (IO). Yielding was limited to BRB members, and afterwards the yielding occurred on beams until collapse. The results of modal pushover and time history analysis for 15-story structure are similar, thus modal pushover can be used to predict the performance of regular structural system with BRB.Keywords: structural performance, buckling restrained brace, immediate occupancy, modal pushover analysis, nonlinear time history analysis

Impact of the Vertical Component of Earthquake Ground Motion in the Performance Level of Steel Buildings

This study discusses the impact of the vertical component of earthquake ground motion in the performance level of steel building subjected to earthquake excitations. Analyses are carried out for the strong column-weak beam philosophy because the structural performance is focused on these elements. A realistic steel frame is also considered to investigate the impact of including the seismic vertical component in the non-linear response of the building. The main findings of this study are: (1) When an analysis is performed by considering the horizontal and vertical components of ground motion acting simultaneously (near the causative fault), larger plastic rotations in the beams are obtained as compared to those resulting by considering only the horizontal component. (2) Due to the previous finding, if a codified criterion to inspect the steel beams performance in terms of the plastic rotation is considered, the beam performance could lie within a different acceptation criterion (i.e., from immediate occupancy to collapse prevention) if the vertical component is included in the analysis.