scholarly journals Seismic Performance of a New Structural Design Solution for First-Story Isolated RC Buildings with Coupled Beam-Column Connections

2019 ◽  
Vol 9 (1) ◽  
pp. 177 ◽  
Author(s):  
Yingxiong Wu ◽  
Ning Liu ◽  
Ai Qi
Keyword(s):  
Structural Design ◽  
Seismic Analysis ◽  
Shaking Table ◽  
Frame Structure ◽  
Design Solution ◽  
Rc Frame ◽  
Seismic Capacity ◽  
Ground Acceleration ◽  
Isolation System ◽  
Frame Buildings

This study proposes a new structural design of the first-story isolation system in reinforced concrete (RC) structures. Compared to the conditional buildings with independent columns, this new design integrates the independent columns with beams to increase the seismic capacity of the building by increasing the integrated stiffness of the coupled columns and the stability of the isolation system. The seismic responses of the proposed structure and the corresponding isolation effect were investigated by performing a series of numerical simulation and shaking table tests on a typical 7-story RC frame structure. The structure models were subjected to four earthquake waves with two PGAs (peak ground acceleration) of 0.30 g and 0.40 g for seismic analysis regarding the peak acceleration and inter-story displacement. Both simulation and testing results showed that the story acceleration and inter-story displacement of the superstructure in the isolated model decreased significantly. While the substructure below the isolation layer had a negligible decrease of acceleration. The connection of beams with concrete columns significantly increases the seismic capacity of the RC frame buildings compared to non-isolated frame buildings. The coupled beam-column connections could thus be potentially adopted in the practical first-story isolation system to avoid the requirements of large column stiffness and large column size.

Comparison Analysis of Typical Buildings in North-South Seismic Belt

2014 ◽  
Vol 501-504 ◽  
pp. 1639-1643
Author(s):  
Jie Ping Liu ◽  
Ning Guo ◽  
Ling Xin Zhang
Keyword(s):  
Seismic Damage ◽  
Frame Structure ◽  
Seismic Belt ◽  
Seismic Capacity ◽  
Reinforced Concrete Frame ◽  
Timber Frame ◽  
Concrete Frame ◽  
The North ◽  
Frame Buildings ◽  
Reinforced Concrete Frame Structure

In North-south earthquake belt, half of more than Ms 8.0 great earthquakes were centralized since the history records were existed in our country. In order to study the typical buildings in this seismic belt, the seismic damages of the typical buildings occurred during 22 earthquakes in North-south earthquake belt, whose earthquake magnitude were more than Ms 6.0, were organized and analyzed. The seismic damage and its matrix of kinds of buildings belonging to the North-south earthquake belt in different intensities were obtained. The statistic results were obtained by comparison and analysis. According to the results of analysis, the seismic capacity of kinds of typical buildings in this region was provided: reinforced concrete frame structure showed fine seismic capability in all previous earthquake whose seismic damage was the slightest in the real statistics results; secondly were those of masonry and mortised timber frame buildings; the seismic damage of buildings, which was combined with timber frame and soil, stone, brick walls was the most serious.

Study on Methods for HCLPF Value of Nonlinear Supports System of Steam Generator

2018 ◽  
Author(s):  
Feng-chun Cai ◽  
Xian-hui Ye ◽  
Qian Huang ◽  
Wenzheng Zhang
Keyword(s):  
Steam Generator ◽  
Nonlinear Model ◽  
Seismic Analysis ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Cost Calculation ◽  
Seismic Capacity ◽  
Ground Acceleration ◽  
Reactor Building ◽  
Nonlinear Time History

High confidence of low probability of failure (HCLPF) values of equipment, representing the seismic capacities of the equipment, are the fundamental ingredient in seismic probability safety assessment (SPSA) and seismic margin analyses (SMA). In this paper, two methods for calculating the HCLPF values of equipment were investigated, fragility analysis, and conservative deterministic failure margin (CDFM). These methods are linear methods. Based on these methods, HCLPF value of equipment can be computed conveniently by scaling the results of the existing seismic analysis. For a nonlinear systems, the HCLPF values based on these linear scaling methods are unrealistic. For a complicated nonlinear equipment or structure, a detail nonlinear model was used to derive the seismic capacity. The results by this method are realistic, but cost calculation time. In this paper, a nonlinear model of reactor coolant system coupled reactor building was built. This model includes the steam generator and considers the nonlinear factors of steam generator such as gap in the supports, plasticity of hot leg and cold leg. Forced motion was applied to the base of reactor building. And seismic response of the steam generator was calculated iteratively by scaling the ground motion level step by step. Based on these calculations, a curve of load on the supports VS peak ground acceleration (PGA) can be obtained. Then based on these curves and allowable load of supports of steam generator, which derived from stress analysis on support of steam generator, seismic capacity of the supports of steam generator was determined. Then the HCLPF Value of the supports of steam generator was obtained by this nonlinear time history analysis and was compared with the results based on the CDFM. The two results were different. Therefore, the HCLPF seismic capacity of equipment with nonlinearity, such as gap nonlinearity, should be calculated by nonlinear time history method.

The Material Behavior and Isolation Benefits of Ball Pendulum System

2006 ◽  
Author(s):  
C. S. Tsai ◽  
Ching-Pei Tsou ◽  
Yung-Chang Lin ◽  
Mei-Ju Chen ◽  
Wen-Shin Chen
Keyword(s):  
Base Isolation ◽  
Ground Motions ◽  
Material Behavior ◽  
Shaking Table ◽  
Ground Acceleration ◽  
Isolation System ◽  
Pendulum System ◽  
Damping Material ◽  
Base Isolation System ◽  
Damping Materials

Earthquake ground motions often result in significant seismic disasters. Strong ground motions will not only cause damage, but may also cause the collapse of structures. People have to face up the suffering from the earthquake damage, and the indirect loss which may be more serious than the damage itself. For example, the antique breaks in museum, and the equipment damages in hi-tech industries are often in huge loss. Therefore, in addition to promoting the earthquake-resistant capacity of a structure, it is also important to ensure the safety of the ancient valuable objects and the instruments in structures. For this reason, this study is aimed at a new damped rolling type base isolation system named the ball pendulum system (BPS) to be installed under the motion sensitive equipment and proceeding all related studies. The isolation device can isolate earthquake from buildings or equipments in any direction by rolling motions and damping materials. This study has conducted a series of component tests and shaking table tests for examining the behaviors of materials and earthquake proof benefits. From the experiment results, it is found that this device can reduce more than 80% of acceleration response under earthquakes with peak ground acceleration of 450 gal. So, the new rolling isolation system with a damping material can be recognized as a feasible and promising way in mitigating the seismic response of equipment.

Shaking Table Tests on a Passive Equipment Isolation System for Earthquake Protection

2009 ◽  
Author(s):  
Maurizio De Angelis ◽  
Salvatore Perno ◽  
Anna Reggio ◽  
Gerardo De Canio ◽  
Nicola Ranieri
Keyword(s):  
Steel Frame ◽  
Shaking Table ◽  
Frame Structure ◽  
Shaking Table Tests ◽  
Isolation System ◽  
Industrial Plants ◽  
Steel Frame Structures ◽  
Rigid Mass ◽  
Passive Isolation ◽  
Steel Frame Structure

The present work refers to steel frame structures in industrial plants. A passive isolation system for seismic protection of a considerable equipment, already present on a frame support structure and rigidly constrained to it, is investigated through both numerical simulations (1+1 DOF system) and shaking table tests on a 1:5 scale two-story steel frame structure. The equipment (e.g. a pipeline, a compressor unit, ...) is modelled as a rigid mass. The optimal design is determined by minimizing the dynamic response of the isolated mass. In order to ensure strenght and serviceability, the response of the frame is also monitored.

Finite Element Analysis of Vertical Continuous Collapse of Six-Story Frame Structure

2010 ◽  
Vol 34-35 ◽  
pp. 1800-1803 ◽  
Author(s):  
Yu Min Zhang ◽  
Cui Juan Sun ◽  
You Po Su ◽  
Jing Yu Su
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Design ◽  
Simulation Analysis ◽  
Progressive Collapse ◽  
The Other ◽  
Frame Structure ◽  
Rc Frame ◽  
Design Codes ◽  
Element Analysis

The capability of structure resisting progressive collapse depends on controlling the dispersion of damage by uncommon agency in the part of the structure and to avoid the destruction just likes the Domino action. For the RC frame, when one column under the beams was broken, the key to avoid progressive collapse is whether the frame beams can bear the column’s load to produce a new way for transmitting the force or not. In this paper, the simulation analysis to a six-layer frame structure which designed by the concrete structural design codes is put up according to the four failure position of columns. The following conclusions are concluded: the damage in vertical region does not appear or appear very little because of a strong stiffness in joint between invalid column and beam. Structural collapse was resulted by the collapse stress from displacement transfering the other end of beam connected with columns.

scholarly journals SEISMIC CAPACITY OF RC FRAME BUILDINGS WITH MASONRY INFILL DAMAGED BY PAST EARTHQUAKES

2020 ◽  
Vol 53 (1) ◽  
pp. 13-21
Author(s):  
Hamood Alwashali ◽  
Md. Shafiul Islam ◽  
Debasish Sen ◽  
Jonathan Monical ◽  
Masaki Maeda
Keyword(s):  
Rc Frame ◽  
Seismic Evaluation ◽  
Seismic Capacity ◽  
Simple Method ◽  
Evaluation Standard ◽  
Masonry Infill ◽  
Frame Buildings ◽  
Recent Earthquakes ◽  
Observed Damage ◽  
Rc Frame Buildings

Many of the buildings which experienced damage in recent earthquakes such as the 2015 Nepal Earthquake were reinforced concrete (RC) frame buildings with unreinforced masonry infill walls. This study proposes a simplified procedure to estimate the in-plane seismic capacity of masonry infilled RC frame buildings based on concepts of the Japanese seismic evaluation standard (JBDPA, [1]). The correlation of seismic capacity and observed damage obtained using a database of 370 existing RC frame buildings with masonry infill that experienced earthquakes in Taiwan, Ecuador and Nepal is investigated. The Is index, which represents the seismic capacity of buildings in the Japanese standard, showed good correlation with the observed damage and proved to be effective as a simple method to estimate seismic capacity. The method was then applied to 103 existing buildings in Bangladesh that have not experienced a major earthquake recently. The results emphasize the necessity for urgent seismic evaluation and retrofitting of buildings in Bangladesh.

Dynamic Response Analysis of RC Structures under Seismic Excitation Considering Strain Rate

2017 ◽  
Vol 873 ◽  
pp. 254-258
Author(s):  
Hao Zhang ◽  
Guang Wei Cao ◽  
Yong Qiang Li
Keyword(s):  
Dynamic Response ◽  
Strain Rate ◽  
Structural Model ◽  
Vertical Component ◽  
Shear Wall ◽  
Shaking Table ◽  
Frame Structure ◽  
Wall Structure ◽  
Response Analysis ◽  
Rc Frame

Considering the effects of strain rate, the nonlinear dynamic response of two reinforced concrete(RC)structuresisstudied under seismic excitationsin this paper. Firstly, based on the model in a shaking table test, a three-dimensional finite element model of RC frame-shear wall structural model subjected to both horizontal and vertical component seismic excitations is established. The structural model is a three-story RC frame-shear wall structure, which consists of RC slabs, RC columns and transverse spandrel beams.Afringeframe is infilled by a RCshear wall.Then, According to the practice engineering, a multi-story RC frame structure is also established. Finally, the dynamic response of the structures is investigated using nonlinear seismic analytical method considering the effects of strain rate. These results may provide a reference for seismic design of RC structure.

scholarly journals Dynamic analysis of multilayer-reinforced concrete frame structures based on NewMark-β method

2021 ◽  
Vol 60 (1) ◽  
pp. 567-577
Author(s):  
Yizhe Liu ◽  
Bofang Zhang ◽  
Ting Wang ◽  
Tian Su ◽  
Hanyang Chen
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Frame Structure ◽  
Frame Structures ◽  
Stiffness Coefficient ◽  
Rc Frame ◽  
Rc Frame Structure ◽  
Rc Structure ◽  
Reduction Coefficient ◽  
The Impact

Abstract The analysis method of the simplified structure formation model provides the basis for the analysis of the reinforced concrete (RC) structure under earthquake and dynamic load, which has important significance for seismic analysis of RC structure. In this paper, the three-layer RC frame structure is simulated and analyzed by MATLAB based on the NewMark-β method, considering the influence of time-varying simple harmonic loads and seismic waves on acceleration, displacement, and velocity of RC structure. The vibration response of the RC structure is analyzed by introducing the stiffness reduction coefficient. The results show that NewMark-β method provides a new idea for the seismic response of RC frame structures, making the seismic analysis of frame structures more practical; the variation range of its elastic modulus is obtained through the analysis of the constitutive model of RC, which provides the basis for the value of the stiffness coefficient; the application of the top load and the bottom load has different structural responses to the RC frame structure, and the impact of the load on the structure is more adverse when the load acts on the bottom; with the change of time, the binding stiffness coefficient will also change, and the stability of the structure will decrease greatly; the function relationship between the acceleration of the third floor and the reduction coefficient of rigidity is obtained by taking different values of the reduction coefficient of rigidity.

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