scholarly journals Seismic Performance Evaluation of Double-Skin Semi-Base-Isolated Building Using Incremental Dynamic Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Mohammad Parsaeimaram ◽  
Congqi Fang ◽  
Xianqi Luo ◽  
Chandan Shakya
Keyword(s):  
Inner Core ◽  
Base Isolation ◽  
Shear Walls ◽  
Dynamic Responses ◽  
Coupling Beams ◽  
Skin Structure ◽  
Seismic Performance Evaluation ◽  
Time Period ◽  
Fixed Base ◽  
Double Skin

Base isolation is a widely accepted earthquake damage prevention technique. This method decouples the superstructure from the base by putting a flexible layer under each column, thereby elongating the time period of structures. Semi-base isolation (SBI) in double-skin structures is an effective technique to reduce the dynamic responses of structures due to earthquake motions, by utilizing the isolation devices in part of it instead of the entire base. This study presents a double-skin structure consisting of outer fixed base frames with shear walls that have been detached from the inner core with a minor gap. The inner core of the structure has been dissociated from the base using the elastomeric bearings. Seismic response of 10-story double-skin structure with inner isolated core was compared to that of inner fixed base core to consider the yielding and collapse probability of the structure using the incremental dynamic analyses (IDA). The results showed that the time period in SBI buildings can be adjusted with the use of coupling beams between the inner and outer frames. Also, the time period and interstory drift ratio are both reduced as more floors are given coupling beams. However, these coupling beams are the most effective at the topmost floors.

scholarly journals Seismic performance of double skin semi-base-isolated structures

2020 ◽  
Vol 143 ◽  
pp. 01048
Author(s):  
Congqi Fang ◽  
Wenyan Dong ◽  
Mohammad Parsaeimaram
Keyword(s):  
Seismic Performance ◽  
Inner Core ◽  
Base Isolation ◽  
Lateral Force ◽  
Hysteretic Behavior ◽  
Earthquake Ground Motion ◽  
Coupling Beams ◽  
Isolation System ◽  
Time Period ◽  
Double Skin

Base isolation technology is a popular and powerful isolation technology. This technique can greatly reduce the seismic response of the structure, so as to reduce the damage to the structure. Base isolation method decouples the superstructure from the base by installing a flexible layer under each column to reduce dynamic response in the earthquake and elongate the time period of structures due to its inherent flexibility. However, the long time period causes large displacement. In addition, base isolation devices are highly vulnerable due to uplift forces produced by lateral force resisting systems (LFRS). In this study, an adjustable structure with a new configuration, namely double skin semi-base-isolated (SBI) structure is presented to solve the above problems. The LFRS is omitted in the proposed SBI structure and the time period and displacement are reduced compared to the conventional base-isolated structure. The forcedeformation behavior of an isolator is modeled as bi-linear hysteretic behavior which can be effectively used to model all isolation system in practice. This study investigates the seismic performance of 10-story double skin SBI reinforced concrete (RC) structure under far-fault earthquake ground motion by numerical method. Results demonstrate that the SBI system is significantly adjustable with the use of RC coupling beams between the inner core and outer frames. By increasing or reducing the number of connected floors in the SBI system, dynamic behaviors of the SBI system can be changed. The adjusted structure can be created by adding and removing RC coupling beams at every arbitrary floor level.

scholarly journals Seismic Performance Evaluation of Multi-Storey Building Having Soft Storey With Different Location of Shear Walls

2020 ◽  
Vol 9 (11) ◽  
pp. 50-55
Keyword(s):  
Shear Walls ◽  
Base Shear ◽  
Soft Storey ◽  
Seismic Performance Evaluation ◽  
Soft Story ◽  
Time Period ◽  
Multistory Building ◽  
Story Drift ◽  
Seismic Behaviors ◽  
Storey Building

Present scenario growth of Multistory building is incredibly high attributable to fast growth everywhere around the globe. Open first story is usually provided for congested parking space, reception lobbies, party areas or any purpose in multistory building. However just in case of multistory building with soft story provides reduced performance. There are numerous aspects that effects on the behavior of multistory building like irregular plan within the structure. In the present work, study of various locations of weak stories is being considered for the analysis. To study of various locations on the seismic behavior of multistory building, linear static analysis (ESA) and linear dynamic analysis (RSA) in ETABs 2016 version is applied. Some seismic constraints like time period, story shear, story displacement, story drift and base shear are tried. The seismic behaviors of multistorey building with soft stories are administered.

Effects of Isolation Damping on Stochastic Response of Structures with Nonlinear Base Isolators

1998 ◽  
Vol 14 (1) ◽  
pp. 95-114 ◽  
Author(s):  
R. S. Jangid ◽  
P. Banerji
Keyword(s):  
Sliding Friction ◽  
Base Isolation ◽  
Equivalent Linearization ◽  
Earthquake Intensity ◽  
Analytical Expression ◽  
Time Period ◽  
Stiffness Properties ◽  
Fixed Base ◽  
Optimum Material ◽  
Design Earthquake

Optimum isolator damping required to minimize absolute acceleration responses to stochastic ground motions in buildings with non-linear resilient-friction base isolation (R-FBI) devices is studied. Using a stochastic equivalent linearization technique, an analytical expression is developed for estimating optimum material damping values in an R-FBI system for a rigid superstructure. This optimum damping value depends on the effective time period and friction coefficient of the R-FBI system and the design earthquake intensity. The fixed base structural time period, damping, and the number of stories also affect the optimum isolator damping values, if the superstructure is flexible. However, the analytical expression mentioned above provides an upper-bound optimum isolator damping value for any superstructure with an R-FBI system subjected to a given earthquake intensity. Comparison of optimum damping values for a linear isolator and the R-FBI system, with identical lateral stiffness properties, illustrates the beneficial effect of sliding friction in reducing the optimum damping in the latter type of isolator, for a given earthquake intensity.

Nondestructive Analysis of Dragonfly Eye Beads from the Warring States Period, Excavated from a Chu Tomb at the Shenmingpu Site, Henan Province, China

2013 ◽  
Vol 19 (2) ◽  
pp. 335-343 ◽  
Author(s):  
Yimin Yang ◽  
Lihua Wang ◽  
Shuya Wei ◽  
Guoding Song ◽  
Jonathan Mark Kenoyer ◽  
...  
Keyword(s):  
Inner Core ◽  
Nondestructive Method ◽  
Henan Province ◽  
Manufacturing Technology ◽  
Warring States Period ◽  
Warring States ◽  
Time Period ◽  
Mold Casting ◽  
Warring State Period ◽  
Manufacturing Features

AbstractDragonfly eye beads are considered to be the earliest types of glass objects in China, and in the past have been considered as evidence of culture interaction or trade between West and East Asia. In this article, synchrotron radiation microcomputed tomography and μ-probe energy dispersive X-ray fluorescence were used to determine the chemical composition, microstructure, and manufacturing technology of four dragonfly eye beads, excavated from a Chu tomb at the Shenmingpu site, Henan Province, China, dated stylistically to the Middle and Late Warring State Period (475 bc–221 bc). First, a nondestructive method was used to differentiate the material types including faience (glazed quartz), frit, glazed pottery (clay ceramic), and glass. Three beads were identified as faience and one bead as glazed pottery. The glaze recipe includes quartz, saltpeter, plant ash, and various copper, and is classified as belonging to the K2O-CaO-SiO2 glass system, which indicates that these beads were not imported from the West. Based on computed tomography slices, the manufacturing technology of the faience eye beads appears to include the use of an inner core, molding technology, and the direct application glazing method. These manufacturing features are consistent with the techniques used in China during this same time period for bronze mold-casting, proto-porcelain, and glass.

Dynamic Nonlinear Analysis of an Hybrid Base Isolation System with Viscous Dampers and Friction Sliders in Parallel

2012 ◽  
Vol 234 ◽  
pp. 96-101 ◽  
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis
Keyword(s):  
Nonlinear Analysis ◽  
Base Isolation ◽  
Three Dimensional ◽  
Time History ◽  
Seismic Action ◽  
Viscous Dampers ◽  
Isolation System ◽  
Fixed Base ◽  
Base Isolation System ◽  
Dynamic Nonlinear Analysis

In the present work we have analyzed a particular base isolation system for the seismic protection of a multi-storey reinforced concrete (RC) building. The viscous dampers and friction sliders are the devices adopted in parallel for realizing the base isolation system. The base isolation structure has been designed and verified according to European seismic code EC8 and by considering for the friction sliders the influence of the sliding velocity on the value of the friction coefficient. A dynamic nonlinear analysis for a three-dimensional base isolated structure has been performed. Recorded accelerograms for bi-directional ground motions have been used which comply with the requirements imposed by EC8 for the representation of a seismic action in a time history analysis. In this paper a comparative analysis is presented between the base isolated structure with the described hybrid base isolation system and the traditional fixed base structure.

scholarly journals Experimental Comparison Study on Cyclic Behavior of Coupled Shear Walls with Two-Level-Yielding Steel Coupling Beam and RC Coupling Beam

2018 ◽  
Author(s):  
Guoqiang LI ◽  
Mengde PANG ◽  
Feifei Sun ◽  
Liulian LI ◽  
Jianyun SUN
Keyword(s):  
Energy Dissipation ◽  
Lateral Displacement ◽  
Shear Walls ◽  
Shear Wall ◽  
Cyclic Behavior ◽  
Experimental Comparison ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Coupled Shear Wall ◽  
Steel Coupling Beam

Coupled shear walls are widely used in high rise buildings, since they can not only provide efficient lateral stiffness but also behave outstanding energy dissipation ability especially for earthquake-resistance. Traditionally, the coupling beams are made of reinforced concrete, which are prone to shear failure due to low aspect ratio and greatly reduce the efficiency and ability of energy dissipation.  For overcoming the shortcoming of concrete reinforced coupling beams (RCB), an innovative steel coupling beams called two-level-yielding steel coupling beam (TYSCB) is invented to balance the demand of stiffness and energy dissipation for coupled shear walls. TYSCBs are made of two parallel steel beams with yielding at two different levels.  To verify and investigate the aseismic behaviour improvement of TYSCB-coupled shear walls, two 1/3 scale, 10-storey coupled shear wall specimens with TYSCB and RCB were tested under both gravity and lateral displacement reversals. These two specimens were designed with the same bearing capacity, thus to be easier to compare. The experimental TYSCB specimen demonstrated more robust cyclic performance. Both specimens reached 1% lateral drift, however, the TYSCB-coupled shear wall showed minimal strength degradation. Additionally, a larger amount of energy was dissipated during each test of the TYSCB specimen, compared with the RCB specimen. Based on the experimental results, design recommendations are provided.

Dynamic structure-soil-structure interaction

1973 ◽  
Vol 63 (4) ◽  
pp. 1289-1303
Author(s):  
J. Enrique Luco ◽  
Luis Contesse
Keyword(s):  
Soil Structure ◽  
Natural Frequencies ◽  
Shear Walls ◽  
Dynamic Structure ◽  
Soil Structure Interaction ◽  
Sh Wave ◽  
Low Frequencies ◽  
High Frequencies ◽  
State Response ◽  
Fixed Base

abstract A study is made of the dynamic interaction, through the soil, between two parallel infinite shear walls placed on rigid foundations. The steady-state response of both structures for a vertically incident SH wave is obtained and compared with the corresponding values resulting from consideration of only one structure. It is found that the additional interaction effects caused by the presence of a second structure are especially important at low frequencies and in the neighborhood of the fixed-base natural frequencies of the second structure. For high frequencies it is sufficient to consider the interaction between each structure and the soil, ignoring the presence of other structures.

Experimental Seismic Performance Evaluation of Unreinforced Brick Masonry Shear Walls

2015 ◽  
Vol 31 (1) ◽  
pp. 215-246 ◽  
Author(s):  
Mohammed Javed ◽  
Guido Magenes ◽  
Bashir Alam ◽  
Akhtar Naeem Khan ◽  
Qaisar Ali ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Primary Source ◽  
Shear Walls ◽  
Brick Masonry ◽  
Stone Masonry ◽  
Masonry Buildings ◽  
Kashmir Earthquake ◽  
Equivalent Viscous Damping ◽  
Seismic Performance Evaluation ◽  
Story Drift

Unreinforced masonry buildings, constructed with stones or bricks, are common in the northern areas of Pakistan. In the October 2005 Kashmir earthquake, the seismic performance of stone masonry buildings was found to be poor, which was the primary source of fatalities. Unreinforced brick masonry (URBM) buildings, however, performed well even in severely jolted areas. The performance of URBM could have been much better if the affected buildings were constructed by using proper guidelines. Taking lessons from the disaster, an experimental investigation, based on typical geometry and precompression levels of the URBM shear walls in the affected region, was conducted to evaluate their seismic performance. Twelve walls were tested in the in-plane direction using quasi-static cyclic loading. First-story drift ratios for various performance levels in URBM buildings are proposed. The influences of relative precompression level and aspect ratio on the damage pattern, ultimate drift ratio, and equivalent viscous damping of the walls are examined.

Pushover Analysis of Base Isolated RC Frame Buildings With Masonry Infills

2019 ◽  
Vol 10 (2) ◽  
pp. 18-31
Author(s):  
Radhikesh Prasad Nanda ◽  
Subhrasmita Majumder
Keyword(s):  
Base Isolation ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Base Shear ◽  
Infilled Frame ◽  
Masonry Infills ◽  
Time Period ◽  
Frame Buildings ◽  
Story Drift ◽  
Rc Frame Buildings

In the present article, the performance of base-isolated infilled frames is studied analytically. The seismic performances of four RC buildings, namely RC bare frame without isolator, RC bare frame with isolator, RC infilled frame without isolator, and RC infilled frame with isolator are analysed. The results show a decrease in base shear value and increase in time period due to base isolated buildings, while these parameters are reversely affected due to infills. The decrease in story drift for the base isolated buildings is in phase while considering infill. Also, it can be inferred that plastic hinge formation is greatly affected by the introduction of masonry infill. Hence, relying on base isolation without considering infills may underestimate the seismic performance.

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