scholarly journals Rapid Prediction of Seismic Incident Angle's Influence on the Damage Level of RC Buildings Using Artificial Neural Networks

2021 ◽  
Author(s):  
Konstantinos Morfidis ◽  
Konstantinos Kostinakis
Keyword(s):  
Neural Networks ◽  
Seismic Response ◽  
Critical Angle ◽  
Structural Parameters ◽  
Time History ◽  
Seismic Damage ◽  
Rc Buildings ◽  
Damage Level ◽  
Pattern Recognition Problem ◽  
Time Required

The angle of seismic excitation is a significant factor of the seismic response of RC buildings. The procedure required for the calculation of the angle for which the potential seismic damage is maximized (critical angle) contains multiple nonlinear time history analyses using in each one of them different angles of incidence. Moreover, the seismic codes recommend the application of more than one accelerograms for the evaluation of seismic response. Thus, the whole procedure becomes time consuming. Herein, a method to reduce the time required for the estimation of the critical angle based on Multilayered Feedforward Perceptron Neural Networks is proposed. The basic idea is the detection of cases in which the critical angle increases the class of seismic damage compared to the class which arises from the application of the seismic motion along the buildings’ structural axes. To this end, the problem is expressed and solved as Pattern Recognition problem. As inputs of networks the ratios of seismic parameters’ values along the two horizontal seismic records' components, as well as appropriately chosen structural parameters, were used. The results of analyses show that the neural networks can reliably detect the cases in which the calculation of the critical angle is essential.

SEISMIC RESPONSE CONTROL OF SUPER HIGH-RISE RC BUILDINGS UTILIZING BUCKLING RESTRAINED BRACES

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Yusuke Maida ◽  
Toshio Maegawa ◽  
Toshihiko Demizu ◽  
Makoto Hamada ◽  
Zhe Qu ◽  
...  
Keyword(s):  
Seismic Response ◽  
Reference Model ◽  
Time History ◽  
Frame Structure ◽  
Nonlinear Time History Analysis ◽  
Rc Beams ◽  
Rc Buildings ◽  
Response Control ◽  
Seismic Response Control ◽  
High Rise

In this paper, the seismic response control of BRBs in super high-rise RC buildings subjected to earthquake ground motions is investigated by nonlinear time history analysis. The analysis model is a 36 stories super high-rise RC building. A bare frame structure is used as a reference model. The parameter of the analysis was the configuration of the BRBs. Two kinds of seismic response controlled building models were examined. In one model, the RC frame was braced by BRBs in each story (each model) and in the other one, each BRB spanned over two stories (over model). The RC beams in the braced span of the over model were abandoned. By comparing the maximum story drift ratio of the reference model with the braced ones, the seismic response control was confirmed for both the each model and the over model. In addition, the over model exhibited almost the same seismic response control as compared to the each model, although the number of BRBs was significantly reduced and the RC beams in the braced span were abandoned.

scholarly journals Seismic Damage Study of Asymmetric Continuous Rigid Frame Bridge Based on Nonlinear Time History Analysis

2015 ◽  
Vol 9 (1) ◽  
pp. 489-494
Author(s):  
Wu Tong ◽  
Sun Quansheng
Keyword(s):  
Seismic Response ◽  
Time History ◽  
Seismic Damage ◽  
Time History Analysis ◽  
Nonlinear Time History Analysis ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Rigid Frame Bridge

Continuous rigid frame bridge is a common type of bridge in California, where is a seismically active areas. Main structural features of the bridge, including asymmetry, hinge structure, concretion of girder and piers affect the seismic response of the bridge significantly. In order to evaluate the safety of the bridge under earthquake, the nonlinear models of girder, limiting steels in hinge, abutment backfill, abutment bearing, pier are simulated in great detail, and a numerical dynamic overall model, composed of the above components, is made through OpenSees program. On the basis of nonlinear time history analysis with Northridge earthquake load, seismic damage of this kind of bridge is monitored. The research results acquire the accurate damage area of the bridge. Under earthquake, asymmetric continuous rigid frame bridge with curved girder tends to move to the external rim of curve. Asymmetry is detrimental to coinstantaneous vibration of frames, which can cause the large nonlinear damage of limiting steels in hinge. Due to large longitudinal relative seismic response between girder and abutment, the damage of abutment bearing and backfill could be severe. The area on the top and bottom of shorter piers in both sides of bridge is vulnerable because longitudinal steel bars in these areas are liable to yield under repeating shaking of earthquake.

Comparison of Interstorey Drift in General RC Buildings in Pounding and No Pounding Case

2020 ◽  
Vol 2 (1) ◽  
pp. 40-47
Author(s):  
Anand Dev Bhatt
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Case Analysis ◽  
Rc Buildings ◽  
Adjacent Buildings ◽  
Sufficient Distance ◽  
Earthquake Load ◽  
Interstorey Drift ◽  
Lower Height

 Inter-storey drift is an important parameter of structural behavior in seismic analysis of buildings. Pounding effect in building simply means collision between adjacent buildings due to earthquake load caused by out of phase vibration of adjacent buildings. There is variation in inter-storey drift of adjacent buildings during pounding case and no pounding case. The main objective of this research was to compare the inter-storey drift of general adjacent RC buildings in pounding and no pounding case. For this study two adjacent RC buildings having same number of stories have been considered. For pounding case analysis there is no gap in between adjacent buildings and for no pounding case analysis there is sufficient distance between adjacent buildings. The model consists of adjacent buildings having 4 and 4 stories but unequal storey height. Both the buildings have same material & sectional properties. Fast non-linear time history analysis was performed by using El-centro earthquake data as ground motion. Adjacent buildings having different overall height were modelled in SAP 2000 v 15 using gap element for pounding case. Finally, analysis was done and inter-storey drift was compared. It was found that in higher building inter-storey drift is greater in no pounding case than in pounding case but in adjacent lower height building the result was reversed. Additionally, it was found that in general residential RC buildings maximum inter-storey drift occurs in 2nd floor.

scholarly journals Investigating the Use of Natural and Artificial Records for Prediction of Seismic Response of Regular and Irregular RC Bridges Considering Displacement Directions

2021 ◽  
Vol 11 (3) ◽  
pp. 906
Author(s):  
Payam Tehrani ◽  
Denis Mitchell
Keyword(s):  
Seismic Response ◽  
Radial Displacement ◽  
Time History ◽  
Good Prediction ◽  
3D Analysis ◽  
Combination Rules ◽  
Principal Axes ◽  
Artificial Records ◽  
The Mean ◽  
Irregular Bridges

The seismic responses of continuous multi-span reinforced concrete (RC) bridges were predicted using inelastic time history analyses (ITHA) and incremental dynamic analysis (IDA). Some important issues in ITHA were studied in this research, including: the effects of using artificial and natural records on predictions of the mean seismic demands, effects of displacement directions on predictions of the mean seismic response, the use of 2D analysis with combination rules for prediction of the response obtained using 3D analysis, and prediction of the maximum radial displacement demands compared to the displacements obtained along the principal axes of the bridges. In addition, IDA was conducted and predictions were obtained at different damage states. These issues were investigated for the case of regular and irregular bridges using three different sets of natural and artificial records. The results indicated that the use of natural and artificial records typically resulted in similar predictions for the cases studied. The effect of displacement direction was important in predicting the mean seismic response. It was shown that 2D analyses with the combination rules resulted in good predictions of the radial displacement demands obtained from 3D analyses. The use of artificial records in IDA resulted in good prediction of the median collapse capacity.

scholarly journals Numerical Study of the Seismic Response of an Instrumented Building with Underground Stories

2021 ◽  
Vol 11 (7) ◽  
pp. 3190
Author(s):  
Edmundo Schanze ◽  
Gilberto Leiva ◽  
Miguel Gómez ◽  
Alvaro Lopez
Keyword(s):  
Seismic Response ◽  
Soil Structure ◽  
Numerical Study ◽  
Time History ◽  
Building Design ◽  
Average Height ◽  
The Real ◽  
Vibration Data ◽  
Finite Element Software ◽  
Stiffness Reduction

Engineering practitioners do not usually include soil–structure interactions in building design; rather, it is common to model and design foundations as embedded joints with joint–based reactions. In some cases, foundation structures are modeled as rigid bodies, embedding the first story into lower vertical elements. Given that the effects of underground floors on the seismic response are not generally included in current building design provisions, it has been little explored in the literature. This work compares and analyzes models to study the effects of different underground stories modeling approaches using earthquake vibration data recorded for the 16–story Alcazar building office in downtown Viña del Mar (Chile). The modeling expands beyond an embedded first story structure to soil with equivalent springs, representing soil–structure interaction (SSI), with varying rigid soil homogeneity. The building was modeled in a finite element software considering only dead load as a static load case because the structure remained in the framing stage when the monitoring system was operating. The instruments registered 72 aftershocks from the 2010 Maule Earthquake, and this study focused on 11 aftershocks of different hypocenters and magnitudes to collect representative information. The comparisons between empirical records and models in this study showed a better fit between the model and the real vibration data for the models that do consider the SSI using horizontal springs attached to the retaining walls of the underground stories. In addition, it was observed that applying a stiffness reduction factor of 0.7 to all elements in deformation verification models for average–height buildings was suitable to analyze the behavior under small earthquakes; better results are obtained embedding the structure in the foundation level than embedding in the street level; the use of horizontal springs with Kuesel’s model with traction for the analysis of the structure yields appropriate results; it is necessary to carefully select the spring constants to be used, paying special attention to the vertical springs. Even though the results presented herein indicate that the use of vertical springs to simulate the SSI of the base slab can result in major differences concerning the real response, it is necessary to obtain more data from instrumentation across a wider variety of structures to continue to evaluate better design and modeling practices. Similarly, further analyses, including nonlinear time–history and high–intensity events, are needed to best regulate building design.

Nonlinear Dynamic Analysis of the Damping Frame Structure System

2012 ◽  
Vol 594-597 ◽  
pp. 886-890 ◽  
Author(s):  
Gan Hong ◽  
Mei Li ◽  
Yi Zhen Yang
Keyword(s):  
Energy Dissipation ◽  
Seismic Response ◽  
Nonlinear Dynamic ◽  
Time History ◽  
Time History Analysis ◽  
Frame Structure ◽  
Force Model ◽  
Operating Characteristics ◽  
Restoring Force ◽  
History Analysis

Abstract. In the paper, take full account of energy dissipation operating characteristics. Interlayer shear-frame structure for the analysis of the Wilson-Θmethod ELASTOPLASTIC schedule, the design of a nonlinear dynamic time history analysis procedure. On this basis, taking into account the restoring force characteristics of the energy dissipation system, the inflection point in the restoring force model treatment, to avoid a result of the calculation results of distortion due to the iterative error. A frame structure seismic response time history analysis results show that: the framework of the energy dissipation significantly lower than the seismic response of the common framework, and its role in the earthquake when more significant.

A Development of the Visco-Elastic Damper for Timber Structure and a Suggestion of the Technological Design Assistance System

2013 ◽  
Vol 778 ◽  
pp. 714-721
Author(s):  
Katsuhiko Kohara ◽  
Takeshi Nomura ◽  
Kazuyoshi Koumoto
Keyword(s):  
Seismic Response ◽  
Elastic Body ◽  
Structural Model ◽  
Time History ◽  
Timber Structure ◽  
Response Analysis ◽  
Frame Design ◽  
Timber Frame ◽  
Loading Tests ◽  
Controlled Structure

Our research team developed a brace type and an angle brace type of the visco-elastic damper on seismic-response controlled structure for timber structure. We performed various dependence evaluations by the materials examination of the styrene olefin-based visco-elastic body which we developed newly. We made a structural model using the performance that loading tests in timber frame. We inspected the validity of the structural model. In addition, we built a technical support system for damper setting by the time history response analysis so that a general design architect was easy to use the damper. We could express dynamics properties of visco-elastic body properties by Voigt model, and the structural model almost accorded with an examination property value. We made a structural model of the whole frame system by Kb of installation rigidity obtained from loading tests in timber frame. Because a design level almost accorded with experimental value, the validity of the frame design on seismic-response controlled structure in consideration of the dependence (distortion, frequency, temperature) of the visco-elastic body was confirmed. This visco-elastic damper on seismic-response controlled structure acquired minister authorization of Ministry of Land, Infrastructure and Transport. In addition, this damper acquired the certification of the Japan Building Disaster Prevention Association.

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