scholarly journals Accounting for the Spatial Variability of Seismic Motion in the Pushover Analysis of Regular and Irregular RC Buildings in the New Italian Building Code

Buildings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 177 ◽  
Author(s):  
Sergio Ruggieri ◽  
Giuseppina Uva
Keyword(s):  
Pushover Analysis ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Building Code ◽  
Rc Buildings ◽  
Capacity Curves ◽  
Conventional Procedure ◽  
Relevant Point ◽  
General Test ◽  
Global And Local

Pushover analysis is the main methodology adopted in practice-oriented applications for investigating the non-linear response of reinforced concrete (RC) buildings; it is applicable for both new and existing buildings. It is well-known that several limitations characterize this methodology and the scientific literature proposes several non-conventional approaches to provide results comparable to those of the more efficient nonlinear dynamic analysis. In most recent seismic guidelines, some improvements have been introduced, in order to overcome the main drawbacks of conventional pushover methods, in view of practice-oriented applications. In particular, new prescriptions are related to the load profiles and the choice of control nodes, aspects that lead to different results in terms of capacity curves and in the safety assessment. Another relevant point is represented by the spatial combination of effects, which suggests the opportunity of executing simultaneous bi-directional pushover analyses. The aim of this paper is to investigate the effects of the new trends followed by some guidelines about pushover analysis, such as the recent 2018 release of the Italian Building Code. In particular, after a general test of the new conventional procedure for the case of RC buildings, a set of case studies has been generated, consisting of three-dimensional RC-archetypes specifically designed and investigated in order to cover the more significant scenarios. The results in terms of global and local performances are processed and critically analyzed, with the aim of appraising the main differences between the traditional and new approaches and identifying the effectiveness and of the actual improvements achieved.

scholarly journals Development and Verification of the Capacity Curve for Two Dimensional Reinforced Concrete Moment-Resisting Frames System under Earthquake Loading

2021 ◽  
Vol 27 (6) ◽  
pp. 73-96
Author(s):  
Haider A Abass ◽  
Husain Khalaf Jarallah
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Three Dimensional ◽  
Automatic Identification ◽  
Two Dimensional ◽  
Seismic Evaluation ◽  
Concrete Frames ◽  
Capacity Curves ◽  
Comparison Of The Results

Pushover analysis is an efficient method for the seismic evaluation of buildings under severe earthquakes. This paper aims to develop and verify the pushover analysis methodology for reinforced concrete frames. This technique depends on a nonlinear representation of the structure by using SAP2000 software. The properties of plastic hinges will be defined by generating the moment-curvature analysis for all the frame sections (beams and columns). The verification of the technique above was compared with the previous study for two-dimensional frames (4-and 7-story frames). The former study leaned on automatic identification of positive and negative moments, where the concrete sections and steel reinforcement quantities the source of these moments. The comparison of the results between the two methodologies was carried out in terms of capacity curves. The results of the conducted comparison highlighted essential points. It was included the potential differences between default and user-defined hinge properties in modeling. The effect of the plastic hinge length and the transverse of shear reinforcement on the capacity curves was also observed. Accordingly, it can be considered that the current methodology in this paper more logistic in the representation of two and three-dimensional structures.  

scholarly journals Application of Nonlinear Static Procedures for the Seismic Assessment of Regular RC Moment Frame Buildings

2014 ◽  
Vol 30 (2) ◽  
pp. 767-794 ◽  
Author(s):  
Michalis Fragiadakis ◽  
Dimitrios Vamvatsikos ◽  
Mark Aschheim
Keyword(s):  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Single Mode ◽  
Moment Frame ◽  
Seismic Demands ◽  
Frame Buildings ◽  
Moment Resisting ◽  
Nonlinear Static ◽  
Global And Local ◽  
Modal Pushover

The applicability of nonlinear static procedures for estimating the seismic demands of typical regular RC moment-resisting frames is evaluated. This work, conducted within the framework of the ATC-76-6 project, shows the degree to which nonlinear static methods can characterize global and local response demands vis-à–vis those determined by nonlinear dynamic analysis for three RC moment-frame buildings. The response quantities (engineering demand parameters) considered are peak story displacements, story drifts, story shears, and floor overturning moments. The single-mode pushover methods evaluated include the N2 and the ASCE-41 coefficient methods. Multi-modal pushover methods, such as modal pushover analysis and the consecutive modal pushover method, were also evaluated. The results indicate that the relatively good performance of the single-mode methods observed for low-rise buildings rapidly deteriorates as the number of stories increases. The multi-modal techniques generally extend the range of applicability of pushover methods, but at the cost of additional computation and without ensuring the reliability of the results.

scholarly journals Effect of joint rigidity on structural behavior of RC buildings

2021 ◽  
Vol 309 ◽  
pp. 01204
Author(s):  
Kurelly Spandana ◽  
Y. Kamala Raju ◽  
G V V Satyanarayana ◽  
Atulkumar Manchalwar
Keyword(s):  
Pushover Analysis ◽  
Structural Behavior ◽  
Rc Buildings ◽  
Capacity Curves ◽  
Software Comparison ◽  
Earthquake Resistant ◽  
Non Linear ◽  
Linear Behaviour ◽  
Joint Rigidity ◽  
Rigid Joints

Non-linear static analysis or pushover analysis is now-a –days generally preferred by many researchers to analyse the non-linear behaviour of the structure. Present study includes the effect of joint rigidity on the behaviour of the structure. A building is modeled with 5 and 10 story and designed for gravity and earthquake resistant loads by considering joint rigidity factor as 0 and 1. The analysis is done in both X and Y directions by using pushover analysis in SAP2000 software. Comparison is made between then capacity curves obtained from designed models of rigidity and non-rigidity models. From the results it is concluded that structure designed using joint rigidity has more strength when compared non-rigid joints.

CASE STUDY OF 3D SEISMIC PUSHOVER ANALYSIS OF INTEGRAL ABUTMENT BRIDGE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Xinya Liu ◽  
Chung C. Fu
Keyword(s):  
Seismic Analysis ◽  
Pushover Analysis ◽  
Three Dimensional ◽  
Maintenance Cost ◽  
Seismic Evaluation ◽  
Integral Abutment ◽  
Capacity Curves ◽  
Abutment Bridges ◽  
Three Dimensional Finite Element

Integral abutment bridges (IABs) have a continuous deck monolithically encased into abutment stem, and typically using single row of piles to carry vertical loads and accommodate longitudinal thermal deformation. Except for smooth pavement and low maintenance cost, IABs have also outperformed conventional seat-type abutment bridges in seismic performance due to increased redundancy, higher damping, and smaller displacements. However, lack of information on their seismic design and performance may have discouraged their use in high seismic zones. In this study, current research and implementation of IABs are comprehensively reviewed. IABs with steel-concrete girders provided by NYDOT are chosen for intensive seismic case study. Three-dimensional finite element models of IABs for nonlinear seismic analysis are elaborated to capture the behavior of components of superstructure, abutment stem, piles, backfill, etc. Pushover analyses are carried out to obtain the capacity curves. Through parametric studies, the effects of bearing are outlined. Conclusions and some recommendations are made for seismic evaluation and design practice of IABs.

Development of Fragility Functions of RC Buildings in Yangon City Using Push over Analysis

2018 ◽  
Vol 13 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Chaitanya Krishna Gadagamma ◽  
Aung Ko Min ◽  
Hideomi Gokon ◽  
Kimiro Meguro ◽  
Khin Than Yu ◽  
...  
Keyword(s):  
Risk Evaluation ◽  
Seismic Vulnerability ◽  
Pushover Analysis ◽  
Disaster Mitigation ◽  
Rc Buildings ◽  
Seismic Vulnerability Assessment ◽  
Capacity Curves ◽  
Damage Probability ◽  
Nonlinear Static ◽  
Static Pushover Analysis

The recent apprehensions about active seismicity in Myanmar is a reminder of the significant hazards caused by earthquakes. Since some cities are subjected to high seismic risk, its assessment can be invaluable for disaster mitigation. This study focused on the development of fragility/damage probability functions for reinforced concrete (RC) buildings in Yangon city because seismic vulnerability assessment is being an essential component of risk evaluation. Nonlinear static pushover analysis is carried out on a group of 54 RC buildings (39 low-rises and 15 high-rises) by varying the material strengths, as well as and analysis based on capacity curves over the demand spectrum with fixed performance points representing the damage probability as a function of both spectral displacement and ground accelerations.

scholarly journals Electric resistivity and seismic refraction tomography, a challenging joint underwater survey at Äspö Hard Rock Laboratory

2016 ◽  
Author(s):  
Mathias Ronczka ◽  
Kristofer Hellman ◽  
Thomas Günther ◽  
Roger Wisen ◽  
Torleif Dahlin
Keyword(s):  
Nuclear Power ◽  
Hard Rock ◽  
Seismic Refraction ◽  
Three Dimensional ◽  
Test Site ◽  
Fracture Zones ◽  
Rock Laboratory ◽  
Refraction Tomography ◽  
Local Point ◽  
General Test

Abstract. Tunnelling below water passages is a challenging task in terms of planning, pre-investigation and construction. Fracture zones in the underlying bedrock lead to low rock quality and thus reduced stability. For natural reasons they tend to be more frequent at water passages. Ground investigations that provide information of the subsurface are necessary prior to the construction phase, but can be logistically difficult. Geophysics can help close the gaps between local point information and produce subsurface images. An approach that combines seismic refraction tomography and electrical resistivity tomography has been tested at the Äspö Hard Rock Laboratory (HRL). The aim was to detect fracture zones in a well-known but logistically and, from a measuring perspective, challenging area. The presented surveys cover a water passage along a part of a tunnel that connects surface facilities with an underground test laboratory. The tunnel is approximately 100 m below and 20 m east of the survey line and gives evidence for one major and several minor fracture zones. The geological and general test site conditions, e.g. with strong powerline noise from the nearby nuclear power plant, are challenging for geophysical measurements. Co-located positions for seismic and ERT sensors and source positions are used on the 450 m long underwater section of the 700 m long profile. Because of a large transition zone that appeared in the ERT result and the missing coverage of the seismic data, fracture zones at the southern and northern part of the underwater passage cannot be detected by separated inversion. A simple synthetic study shows significant three dimensional artefacts corrupting the ERT model that have to be taken into account while interpreting the results. A structural coupling cooperative inversion approach is able to image the northern fracture zone successfully. In addition, previously unknown sedimentary deposits with a significant large thickness are detected in the otherwise unusually well documented geological environment. The results significantly improve imaging of some geologic features, which would have been not detected or misinterpreted otherwise, and combines the images by means of cluster analysis to a conceptual subsurface model.

scholarly journals Evaluation of p-delta effect in structural seismic response

2018 ◽  
Vol 162 ◽  
pp. 04019 ◽  
Author(s):  
Sardasht Sardar ◽  
Ako Hama
Keyword(s):  
Seismic Response ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Steel Structure ◽  
Nonlinear Static Analysis ◽  
Structural Behavior ◽  
Finite Element Software ◽  
History Analysis ◽  
Nonlinear Static

Numerous recent studies have assessed the effect of P-Delta on the structures. This paper investigates the effect of P-Delta in seismic response of structures with different heights. For indicating the effect of P-Delta, nonlinear static analysis (pushover analysis) and nonlinear dynamic analysis (Time history analysis) were conducted by using finite element software. The results showing that the P-Delta has a significant impact on the structural behavior mainly on the peak amplitude of building when the height of the structures increased. In addition, comparison has been made between concrete and steel structure.

scholarly journals Application of ANN to evaluate effective parameters affecting failure load and displacement of RC buildings

2009 ◽  
Vol 9 (3) ◽  
pp. 967-977 ◽  
Author(s):  
M. Hakan Arslan
Keyword(s):  
Failure Load ◽  
Back Propagation ◽  
Load Level ◽  
Effective Parameters ◽  
Rc Buildings ◽  
Building Stock ◽  
Capacity Curves ◽  
Rc Building ◽  
Failure Loads ◽  
Turkish Earthquake Code

Abstract. This study investigated the efficiency of an artificial neural network (ANN) in predicting and determining failure load and failure displacement of multi story reinforced concrete (RC) buildings. The study modeled a RC building with four stories and three bays, with a load bearing system composed of columns and beams. Non-linear static pushover analysis of the key parameters in change defined in Turkish Earthquake Code (TEC-2007) for columns and beams was carried out and the capacity curves, failure loads and displacements were obtained. Totally 720 RC buildings were analyzed according to the change intervals of the parameters chosen. The input parameters were selected as longitudinal bar ratio (ρl) of columns, transverse reinforcement ratio (Asw/sc), axial load level (N/No), column and beam cross section, strength of concrete (fc) and the compression bar ratio (ρ'/ρ) on the beam supports. Data from the nonlinear analysis were assessed with ANN in terms of failure load and failure displacement. For all outputs, ANN was trained and tested using of 11 back-propagation methods. All of the ANN models were found to perform well for both failure loads and displacements. The analyses also indicated that a considerable portion of existing RC building stock in Turkey may not meet the safety standards of the Turkish Earthquake Code (TEC-2007).

Three-Dimensional Elastic Analysis of a Structure with Holes Using Accelerated Coupling-Matrix-Free Iterative s-Version FEM

2018 ◽  
Vol 15 (05) ◽  
pp. 1850036 ◽  
Author(s):  
Yasunori Yusa ◽  
Hiroshi Okada ◽  
Yosuke Yumoto
Keyword(s):  
Search Algorithm ◽  
Three Dimensional ◽  
Convergence Acceleration ◽  
Computational Time ◽  
Elastic Analysis ◽  
Coupling Matrix ◽  
Acceleration Techniques ◽  
Key Techniques ◽  
Global And Local ◽  
Matrix Free

Some improvements of the coupling-matrix-free iterative s-version finite element method (FEM) to shorten its computational time are proposed. Then, the proposed method is applied to three-dimensional stress concentration problems. For sufficiently small computational time for practical use, two key techniques are introduced. First, the iteration is accelerated drastically by using the proposed convergence acceleration techniques. Secondly, stress transfers between global and local meshes are accelerated considerably by a bucket search algorithm. The proposed method was more than one hundred times faster than the straightforward algorithm of the coupling-matrix-free iterative s-version FEM.

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