Optimum Location Analysis of Story Isolation System on High Rise Building

Abstract Various studies have been carried out to evaluate the feasibility and effectiveness of the story isolation system. The results obtained are also quite impressive, where the story isolation system gave a better story drift reduction than the base isolation system. However, these studies only focused on low-rise buildings, even though the story isolation system will be more engaging if it could also be compatible with high-rise buildings. In this study, a numerical analysis will be carried out on 30-, 40-, 50-, and 60-story buildings to evaluate the story isolator’s location, so that the system gives an optimum reduction of story drift and story shear. Then a general solution is sought to become a reference for buildings with different plans and heights. Keywords: Story isolation system, story isolator optimum location, high-rise building. Abstract Berbagai penelitian telah dilakukan untuk mengevaluasi kelayakan dan efektivitas sistem isolasi tingkat. Hasil yang diperoleh juga cukup mengesankan, dimana sistem isolasi tingkat memberikan reduksi simpangan antar tingkat yang lebih baik dibandingkan dengan sistem isolasi dasar. Namun, studi tersebut hanya berfokus pada bangunan bertingkat rendah, padahal sistem isolasi lantai akan lebih menarik jika dapat juga digunakan pada bangunan bertingkat tinggi. Dalam studi ini, analisis numerik akan dilakukan pada bangunan berlantai 30, 40, 50, dan 60 untuk mengevaluasi lokasi isolator tingkat yang memberikan reduksi simpangan tingkat dan geser tingkat terbesar. Kemudian dicari solusi umum untuk menjadi acuan untuk bangunan dengan denah dan ketinggian yang berbeda. Kata kunci: Sistem isolasi tingkat, lokasi optimum isolator tingkat, bangunan bertingkat tinggi.Berbagai penelitian telah dilakukan untuk mengevaluasi kelayakan dan efektivitas sistem isolasi tingkat. Hasil yang diperoleh juga cukup mengesankan, dimana sistem isolasi tingkat memberikan reduksi simpangan antar tingkat yang lebih baik dibandingkan dengan sistem isolasi dasar. Namun, studi tersebut hanya berfokus pada bangunan bertingkat rendah, padahal sistem isolasi lantai akan lebih menarik jika dapat juga digunakan pada bangunan bertingkat tinggi. Dalam studi ini, analisis numerik akan dilakukan pada bangunan berlantai 30, 40, 50, dan 60 untuk mengevaluasi lokasi isolator tingkat yang memberikan reduksi simpangan tingkat dan geser tingkat terbesar. Kemudian dicari solusi umum untuk menjadi acuan untuk bangunan dengan denah dan ketinggian yang berbeda. Kata kunci: Sistem isolasi tingkat, lokasi optimum isolator tingkat, bangunan bertingkat tinggi

The Evolution of Seismic Design Provisions in Indonesia’s National Bridge Code

To accommodate increased seismic hazards in Indonesia, provisions regarding structural details on seismic regulations have been tightened. In this paper, the variations in seismic hazard and detailing requirements from bridge code era before 1990 to the present was provided. To examine the bridge performance, pushover analysis was carried out based on the latest bridge code SNI 2833:2016/Seismic Map 2017. From the analysis results, the performance of older bridges would typically be less than more recently designed structures.  The performance level of the bridge in the era before SNI 2833:2016/Seismic Map 2017 will be Operational-Life Safety (LS) whereas the performance level of the bridge designed with SNI 2833:2016 will be Elastic – Operational. Referring to NCHRP 949 for bridge performance level evaluation, results show that the performance level of the bridge still satisfies the requirement, which is Life Safety under upper-level earthquake. Therefore, the existing bridge shows adequate capacity under the current seismic load Seismic Map 2017 (7% probability of exceedance in 75 years (RP= 1000 years)). Evaluation of seismic vulnerability needs to be done to ensure the safety of the existing bridges in Indonesia, most of which are located in earthquake-prone areas, especially those that were designed with older version regulations

Experimental Study of Wind Flow in a Street Canyon between High-Rise Buildings Using PIV

In recent years there have been several occasions of failure of non-buildings such as billboard towers and pedestrian bridges around high-rise areas in urban Indonesia. Most cases did not occur during any particular high-speed wind gusts but rather during normal wind speed. This research aimed to show the increase in wind load for structures built between high-rise buildings. A simplified cluster of 4 symmetrical high-rise building was investigated. The study used a wind tunnel and a Particle Image Velocimetry (PIV) device in the experiment. Several angles of attack and also different distances between buildings were investigated to see the impact of these parameters on the wind flow between the buildings. Wind flow experiences an interaction flow in all central areas, which translates into an increase in speed. The change in distance between buildings changes the behavior of the flow in the cross area while a change in the angle of attack of the wind does not influence the amplification factor. The results show that there was an increase from 7 to 44% in wind speed due to the street canyons and that the highest amplification occurred with an angle of attack of 0°

The Evolution of Seismic Design Provisions in Indonesia’s National Bridge Code

To accommodate increased seismic hazards in Indonesia, provisions regarding structural details on seismic regulations have been tightened. In this paper, the variations in seismic hazard and detailing requirements from bridge code era before 1990 to the present was provided. To examine the bridge performance, pushover analysis was carried out based on the latest bridge code SNI 2833:2016/Seismic Map 2017. From the analysis results, the performance of older bridges would typically be less than more recently designed structures.  The performance level of the bridge in the era before SNI 2833:2016/Seismic Map 2017 will be Operational-Life Safety (LS) whereas the performance level of the bridge designed with SNI 2833:2016 will be Elastic – Operational. Referring to NCHRP 949 for bridge performance level evaluation, results show that the performance level of the bridge still satisfies the requirement, which is Life Safety under upper-level earthquake. Therefore, the existing bridge shows adequate capacity under the current seismic load Seismic Map 2017 (7% probability of exceedance in 75 years (RP= 1000 years)). Evaluation of seismic vulnerability needs to be done to ensure the safety of the existing bridges in Indonesia, most of which are located in earthquake-prone areas, especially those that were designed with older version regulations

Studi Perbandingan Analisis Statik dan Dinamik pada Girder Kereta Cepat

Faktor perbesaran dinamis (dynamic amplification factor – DMF) lazim digunakan oleh perencana untuk memperbesar respons struktur (gaya dalam, perpindahan) yang didapatkan dari analisi statis untuk mengakomodasi efek dinamis dari laju kendaraan. Di dalam beberapa Code, faktor amplifikasi dinamis cenderung berupa rumus empiris yang tergantung pada bentangan struktur, bukan pada laju kendaraan. Studi ini hendak mengevaluasi berapa faktor amplifikasi dinamis yang mungkin terjadi pada momen lentur dan lendutan girder kereta apabila laju kendaraan divariasikan dari 100 km/jam s.d. 550 km/jam. Pemodelan dan analisis didasarkan pada girder tipikal untuk kereta cepat untuk bentang 32,6 m dengan menggunakan software metode elemen hingga. Hasil analisis software pertama-tama diverifikasi dengan solusi eksak dari persamaan gerak dinamik untuk beban terpusat berjalan (moving load), kemudian dilanjutkan dengan analisis terhadap beban kereta cepat CR400AF. Perbandingan antara respons dinamis dan statis (faktor amplifikasi dinamis) yang direkomendasikan oleh Code cenderung konservatif untuk laju kendaraan rencana 350 km/jam

KONTROL AKTIF KEKAKUAN DAN MASSA STRUKTUR DENGAN MENGGUNAKAN JARINGAN SARAF TIRUAN

This paper presents a theoretical and experimental study on active control structure excited by seismic loads using artiï¬cial neural network Artiï¬cial neural network is used to calculate the control force based on acceleration of the structure which is obtained by accelerometer measurement. The control mechanism is implemented on the structure using active stiflness and mass based on continuous vibration measurement. The reability of the active control system with artiï¬cial neural network has been tested experimentally using a reduced model of two=storey steel flame excited by base acceleration through a small shaking table. The experimental study shows that the artiï¬cial neural network control method gives satisfactory results for many types of base excitation such as random and El-Centro N-S earthquake accelerations. The neuro control algorithm is simple and reduces consideranbly computational time

Studi Pengaruh Kenaikan Kekakuan Metallic Damper Terhadap Respon Seismik Struktur Rangka Baja dengan Energi Redaman Tambahan Peredam ADAS (Added Damping and Stifness)

Abstrak. Manfaat alat pendisipasi energi tambahan dikenal baik dalam bidang rekayasa struktur untuk mendisipasi energi akibat gempa. Perilaku seismik struktur rangka baja dengan energi redaman tambahan ADAS dijadikan sebagai konsentrasi utama pada penelitian ini. Tiga model sampel ADAS didisain dan diuji secara eksperimental untuk memperoleh metallic yielding damper model baru. Tujuan utama studi ini adalah mengetahui rasio kekakuan optimum ADAS (KD) terhadap kekakuan struktur tiap lantai (KS). Program PERFORM 3D dan dua catatan gempa (El Centro dan San Fernando) digunakan untuk mengetahui respon seismik struktur. Metode analisis yang digunakan adalah analisis riwayat waktu nonlinear. Rasio energi histeresis struktur terhadap energi input yang dikerjakan gempa ke struktur juga dibahas pada studi ini. Hasilnya, untuk menaikkan kapasitas dan mengurangi kerusakan struktur akibat gempa sebanyak mungkin bisa dilakukan dengan menaikkan kekakuan peredam tambahan ADAS.Abstract. The benefit of extra energy absorber is well known in the field structural engineering to dissipate energy caused by earthquakes. Seismic behaviors of steel frame structure with additional damping energy ADAS are the main concentration in this study. Three samples ADAS models were designed and tested eksperimentally to obtain a new model of metallic yielding dampers. The main objective of this study is to determine the optimum stiffness ratio of ADAS (KD) to storey stiffness of stuctures (KS). PERFORM 3D software and two earthquake records (El Centro and San Fernando) were used to determine the seismic responses of structure. The analytical method used is the nonlinear time history analysis. The ratio of hysteretic energy of the structure to earthquake input energy is also discussed in this study. The result, increasing capacity and reducing structural damage caused by the earthquake as much as possible can be conducted by increasing additional ADAS damper stiffness

Pengembangan Sistem Isolasi Seismik pada Struktur Bangunan yang Dikenai Beban Gempa sebagai Solusi untuk Membatasi Respon Struktur

Abstrak. Penelitian ini membahas studi teori dan eksperimental mengenai kontrol pasif getaran pada struktur yang mengalami beban eksitasi gempa dengan menggunakan teknik isolasi yang dilakukan pada dasar struktur bangunan. Pada penelitian ini diusulkan penggunaan sistem isolasi dasar dengan menggunakan bantalan karet yang diletakkan di antara kolom pada lantai dasar dengan pondasi yang diharapkan mampu memperkecil perpindahan horisontal struktur bangunan. Model eksperimental yang digunakan adalah model portal baja dua tingkat dengan isolator bantalan karet pada tumpuannya dan diberi beban eksitasi dinamik dengan menggunakan meja getar. Hasil studi teori dan eksperimental untuk berbagai beban dinamik seperti percepatan horisontal gempa El Centro N-S menunjukkan penggunaan isolator pada dasar struktur bangunan memberikan hasil yang memuaskan dalam hal pengurangan tingkat getaran sehingga dapat meningkatkan kualitas keamanan dan kenyamanan struktur. Selain itu penggunaan isolator dasar pada struktur bangunan sangat menguntungkan karena pelaksanaannya yang relatif sederhana.Abstract. This study presents a theoretical and experimental study on passive vibration control for structures which are subjected to earthquake excitations using isolation technique which is implemented on the base of the building structure. The base isolation system, made of rubber pads, was proposed in this study to reduce the relative horizontal displacement of the structure. The experimental model for the study is a two-storey steel frame with rubber pads installed on its base. The dynamic excitations were given to the structure through a small shaking table. The theoretical and experimental studies for various dynamic loads, such as sinusoidal acceleration and simulation of El Centro NS earthquake acceleration, show that the use of the base isolator on the structure gives satisfactory results. The base isolation system reduces significantly the vibration level and improves the quality of safety and comfort of the structure. In addition, the use of the base isolator on the structure is very attractive because its implementation is relatively simple

Numerical Analysis Of Viscous Wall Dampers On Steel Frame

The structure is designed to minimize component damaged, one of them is using a damping system. Viscous Wall Damper is one of the damping systems, using high viscosity liquids as dampers. The viscous wall damper is represented by an Exponential Maxwell Damper model. Much of the literature shows the ability of viscous wall damper by experimental studies, but few of them had discussed numerically. This article will present an analytical model of the viscous wall damper, add viscous wall damper element to an existing frame and numerical analysis. The analysis was performed by a computer application on a steel space frame that excited a combination of three earthquake types. The influence of Viscous Wall Damper showed that a significant decrement of displacement u1 at the structure with Viscous Wall Damper in X & Y direction (50,78%) and with Viscous Wall Damper in Y direction (23,96%). The decrement displacement happened in all structure. At the end of the analysis shows the reduced of the structure periods, the structure response (displacement, velocity, and acceleration). All these results conclude that the structural components damaged due to loads can be greatly reduced