scholarly journals Seismic performance of steel moment and hinged frames with rocking shear walls

2021 ◽  
Author(s):  
Mehrdad Piri ◽  
Ali Massumi
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Shear Walls ◽  
Seismic Energy ◽  
Shear Wall ◽  
3D Models ◽  
Initial Position ◽  
Economic Effects ◽  
Moment Frames ◽  
Nonlinear Time History

Abstract The addition of a rocking structural system will soften the connection between a foundation and superstructure and help the beam-column connections to become softer than typical ones. These structures, with the addition of rocking structural systems, follow the elastic gap opening mechanism to soften the structural seismic response. Post-tensioned energy dissipating devices and dampers are used in rocking systems to enable the structure to return to its initial position (self-centering) and to dissipate seismic energy, respectively. The current study investigated the use of a rocking shear wall system in steel moment-resistant and hinged frames and determined the amount of damage and the economic effects on the structures. For this purpose, 3D models of 3-, 9-, and 20-story SAC-project steel frames were modeled and validated according to FEMA-355C and then a hybrid rocking shear wall was added to them. The structures were designed and modeled according to common seismic codes and were analyzed using nonlinear time history when subjected to a series of records from FEMA-355C. The results showed that the use of a hinged frame attached to a rocking concrete shear wall (HFR) increased the fundamental period and inter-story displacement and decreased the amount of steel used in the 3-, 9-, and 20-story models compared to similar models with fixed connections in moment frames (MFR). The HFR shear wall models exhibited better seismic performance than MFR models, which increased their load-bearing capacity and reduced their weight, which reduced construction costs.

scholarly journals Investigation of Behaviors of Concrete Shear Wall in High-Rise Steel Buildings

2018 ◽  
Vol 7 (3.2) ◽  
pp. 135
Author(s):  
Hajiyev Mukhlis Ahmad ◽  
Hasan Dabbaghasadollahi Poor
Keyword(s):  
Time History ◽  
Shear Walls ◽  
Steel Structures ◽  
Shear Wall ◽  
Target Point ◽  
Steel Buildings ◽  
High Rise ◽  
Reinforced Steel ◽  
Structural Plan ◽  
Nonlinear Time History

This study focuses on an analytical study on reinforced steel structures with concrete shear wall. The structures studied was analyzed using nonlinear time history method and the effect of installing  concrete shear walls in the structural plan on the target point displacement. By comparing the roofs' displacement diagrams in different structures with different layout of the shear wall in the plan, it is concluded that in order to achieve the proper result in the design of the structures, the shear walls must be located in the middle of the plan in form of core and enclosed with structural columns.  

scholarly journals Assessment of the Seismic Performance for a Low-Code RC Shear Walls Structure in Bucharest (Romania)

2020 ◽  
Vol 14 (1) ◽  
pp. 111-123
Author(s):  
Florin Pavel ◽  
Radu Vacareanu
Keyword(s):  
Seismic Performance ◽  
Significant Proportion ◽  
Time History ◽  
Shear Walls ◽  
Seismic Rehabilitation ◽  
Nonlinear Time History Analyses ◽  
Principal Directions ◽  
Section Type ◽  
Nonlinear Time History ◽  
Sectional Analysis

Background: Low-code RC shear walls structures house a significant proportion (over 20%) of the inhabitants of Bucharest. Objective: In this research, the seismic performance of a low-code reinforced concrete shear walls structure located in various sites in Bucharest (Romania) is assessed. Methods: The seismic performance is assessed using both static and dynamic nonlinear time-history analyses, as well as detailed sectional analysis of the RC shear walls. Results: The results show that the structure has significant capacity differences in the two principal directions. Moreover, it has been observed that the maximum top displacements obtained from nonlinear time history analyses are larger in the transversal direction. Conclusion: Considering the behaviour of such structures during the 1977 Vrancea earthquake, the fact that these structures are already 40 – 50 years old and given the results of some of the analyses shown in this study, it can be concluded that immediate seismic rehabilitation measures are needed in order to correct, at least partially the structural issues of this section type.

Study of the Seismic Performance of Composite Shear Walls with Embedded Steel Truss For Use in High-rise Buildings

Bauingenieur ◽  
2020 ◽  
Vol 95 (11) ◽  
pp. S 12-S 21
Author(s):  
Rudolf Heuer ◽  
Andreas Kolbisch ◽  
Ali Khazei
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Seismic Performance ◽  
Time History ◽  
Shear Walls ◽  
Shear Wall ◽  
Time History Analysis ◽  
Braced Frames ◽  
History Analysis ◽  
Composite Wall

Abstract The composite wall with encased steel braces (ESB wall) is a novel type of steel–concrete composite wall that consists of a steel braced frame embedded in reinforced concrete. This arrangement is supposed to enhance the seismic performance of the wall, as the steel columns encased in the boundary elements can increase the flexural strength of the wall and the steel braces encased in the web can increase the shear strength. ESB walls have seen use in super tall building structures constructed in regions of high seismicity. The ESB walls are commonly used on stories where the shear force demand is very high. Currently, no design guidelines exist for the design of ESB Walls in the Eurocode. More research is required before a distinct set of guidelines can be prescribed for the design of ESB Walls. The present research will investigate behavior of composite walls with encased steel braces (ESB walls). Time history analysis will be performed to examine the shear strength and stiffness of the ESB walls. In this study, two frames with three floors and five floors will be modeled in ABAQUS software. Then the X- shaped braces and inverted V brace is added to frames. Later, reinforced concrete shear wall will be added to braced frames, so the steel braces encased in the reinforced concrete shear wall. Time history analysis, on the braced frames will be done Compare and note with each other. The results of the study are in good agreement with those of previous studies. However, none of these studies examined the effect of using V- and X-shaped struts and shear walls simultaneously, nor did they examine which struts reinforce the structures more strongly against earthquake vibrations. This has led the study to examine the effect of these reinforcements under various earthquakes. In future studies, reinforced concrete structures can also be used in addition to steel structures, and the results can be compared. In addition, these braces can also be used in other parts of the building. To meet this objective, one can use the very important data provided in this thesis, and ultimately better and more accurate results can be extracted using this approach. The main aim of this thesis is to study the effect of increasing the number of floors on how to extend the stress on the building structure. To this end, the number of floors increased from three to five. Therefore, it can be concluded that an increase in the number of floors also more than 5 storey causes stress values, but these modes are quite consistent with the three- and five-storey buildings.

scholarly journals Numerical study on the seismic performance of hybrid steel moment frames with CLT balloon shear walls

2020 ◽  
Author(s):  
◽  
Mehdi Khajehpour
Keyword(s):  
Numerical Study ◽  
Time History ◽  
Shear Walls ◽  
Shear Wall ◽  
Hybrid Structure ◽  
Reduction Factor ◽  
Base Shear ◽  
Moment Frames ◽  
Response Modification Factor ◽  
Capacity Curves

A proposed hybrid lateral load resisting system combining a moderately ductile steel moment resisting frame (SMRF) with Cross-laminated Timber (CLT) balloon-framed shear walls is investigated on 8, 12 and 16-storey case-study buildings using equivalent static, linear dynamic (modal), nonlinear static (push-over) and nonlinear dynamic (time history) analyses. First, a SMRF is designed using ETABS, then the hybrid structures are analysed in OpenSees. By adding the CLT shear wall to steel moment frame, the period of structure decreased and its stiffness increased. The time history analyses result revealed that by adding the CLT shear wall the maximum drift decreased, while the maximum base shear in hybrid structure slightly increased. The hold down uplift forces under earthquake records are reported and compared to each other. Using push-over capacity-curves, a ductility reduction factor of 3.6, an over strength factor of 1.57 and a seismic response modification factor of 5.67 are derived.

Study on Rational Ratios of Lateral Stiffness for Masonry Building with Frame Structure at First Two Stories

2012 ◽  
Vol 174-177 ◽  
pp. 2012-2015
Author(s):  
Xiao Long Zhou ◽  
Ying Min Li ◽  
Lin Bo Song ◽  
Qian Tan
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Shear Wall ◽  
Calculation Model ◽  
Frame Structure ◽  
Wall Structure ◽  
Masonry Building ◽  
Lateral Stiffness ◽  
Stiffness Ratio ◽  
Lateral Stiffness Ratio

There are two typical seismic damage characteristics to the masonry building with frame shear wall structure at first two stories, and the lateral stiffness ratio of the third storey to the second storey is one of the key factors mostly affecting the seismic performance of this kind of building. However, some factors are not considered sufficiently in current Chinese seismic codes. According to the theory of performance-based seismic design, the seismic performance of this kind of structure is analyzed in this paper by taking time-history analysis on models which with different storey stiffness ratios. The results show that when the lateral stiffness ratio controlled in a reasonable range, the upper masonry deformation can be ensured in a range of elastic roughly, and the bottom frame can be guaranteed to have sufficient deformation and energy dissipation capacity. Finally, according to the seismic performance characteristics of masonry building with frame shear wall structure at first two stories, especially the characteristics under strong earthquakes, a method of simplified calculation model for the upper masonry is discussed in this paper.

Study on Seismic Behavior of the L-Shape Steel Reinforced Concrete Short-Pier Shear Wall with Different Concrete Strength

2013 ◽  
Vol 353-356 ◽  
pp. 1990-1999
Author(s):  
Yi Sheng Su ◽  
Er Cong Meng ◽  
Zu Lin Xiao ◽  
Yun Dong Pi ◽  
Yi Bin Yang
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Seismic Performance ◽  
Seismic Behavior ◽  
Concrete Strength ◽  
Shear Walls ◽  
Shear Wall ◽  
Simulation Software ◽  
Steel Reinforced Concrete ◽  
Shrinkage Effect

In order to discuss the effect of different concrete strength on the seismic behavior of the L-shape steel reinforced concrete (SRC) short-pier shear wall , this article analyze three L-shape steel reinforced concrete short-pier shear walls of different concrete strength with the numerical simulation software ABAQUS, revealing the effects of concrete strength on the walls seismic behavior. The results of the study show that the concrete strength obviously influence the seismic performance. With the concrete strength grade rise, the bearing capacity of the shear wall becomes large, the ductility becomes low, the pinch shrinkage effect of the hysteresis loop becomes more obvious.

scholarly journals Steel Plate Cold-Rolled Section Steel Embedded High-Strength Concrete Low-Rise Shear Wall Seismic Performance

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Min Gan ◽  
Yu Yu ◽  
Liren Li ◽  
Xisheng Lu
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
Steel Plate ◽  
Shear Walls ◽  
High Strength ◽  
Shear Wall ◽  
Steel Plates ◽  
Strength Concrete

Four test pieces with different steel plate center-to-center distances and reinforcement ratios are subjected to low-cycle repeat quasistatic loading to optimize properties as failure mode, hysteretic curve, skeleton curve, energy dissipation parameters, strength parameters, and seismic performance of high-strength concrete low-rise shear walls. The embedded steel plates are shown to effectively restrict wall crack propagation, enhance the overall steel ratio, and improve the failure mode of the wall while reducing the degree of brittle failure. Under the same conditions, increasing the spacing between the steel plates in the steel plate concrete shear wall can effectively preserve the horizontal bearing capacity of the shear wall under an ultimate load. The embedded steel plates perform better than concealed bracing in delaying stiffness degeneration in the low-rise shear walls, thus safeguarding their long-term bearing capacity. The results presented here may provide a workable basis for shear wall design optimization.

scholarly journals Influence of Optimal Intensity Measures Selection in Engineering Demand Parameter of Fixed Jacket Offshore Platform

2021 ◽  
Vol 11 (22) ◽  
pp. 10745
Author(s):  
Sajib Sarker ◽  
Dookie Kim ◽  
Md Samdani Azad ◽  
Chana Sinsabvarodom ◽  
Seongoh Guk
Keyword(s):  
Seismic Performance ◽  
Oil And Gas ◽  
Time History ◽  
Coefficient Of Determination ◽  
Statistical Parameters ◽  
Ground Acceleration ◽  
Jacket Platform ◽  
Intensity Measures ◽  
Optimal Intensity ◽  
Nonlinear Time History

This research identifies the significant optimal intensity measures (IM) for seismic performance assessments of the fixed offshore jacket platforms. A four-legged jacket platform for the oil and gas operation is deployed to investigate the seismic performance. The jacket platform is applied with nonlinearly modeled using finite element (FE) software OpenSees. A total of 80 ground motions and 21 different IMs are incorporated for numerical analyses. Nonlinear time-history analyses are performed to obtain the jacket structure’s engineering demand parameters (EDP): peak acceleration and displacement at the top of the structure. Four important statistical parameters: practicality, efficiency, proficiency, and coefficient of determination, are then calculated to find the significant IMs for seismic performance of the jacket structure. The results show that acceleration-related IMs: effective design acceleration (EDA), A95 parameter, and peak ground acceleration (PGA) are optimal IMs, and the acceleration-related IMs have good agreements with the acceleration-related EDP.

Effect of bidirectional excitation on seismic performance of regular RC frame buildings designed for modern codes

2021 ◽  
pp. 875529302110478
Author(s):  
Payal Gwalani ◽  
Yogendra Singh ◽  
Humberto Varum
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Inelastic Behavior ◽  
Moment Frame ◽  
Frame Buildings ◽  
Bidirectional Excitation ◽  
Rc Frame Buildings ◽  
Nonlinear Time History ◽  
Hinge Model

The existing practice to estimate seismic performance of a regular building is to carry out nonlinear time history analysis using two-dimensional models subjected to unidirectional excitations, even though the multiple components of ground motion can affect the seismic response, significantly. During seismic shaking, columns are invariably subjected to bending in two orthogonal vertical planes, which leads to a complex interaction of axial force with the biaxial bending moments. This article compares the seismic performance of regular and symmetric RC moment frame buildings for unidirectional and bidirectional ground motions. The buildings are designed and detailed according to the Indian codes, which are at par with the other modern seismic codes. A fiber-hinge model, duly calibrated with the biaxial experimental results, is utilized to simulate the inelastic behavior of columns under bidirectional bending. A comparison of the estimated seismic collapse capacity is presented, illustrating the importance of considering the bidirectional effects. The results from fragility analysis indicate that the failure probabilities of buildings under the bidirectional excitation are significantly higher as compared to those obtained under the unidirectional excitation.

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