Seismic behavior of MSCSS based on story drift and failure path

A new model that can simulate the behavior of construction joint subjected to seismic forces was proposed. Nonlinear time-history analysis was carried out for reinforced concrete regular frame structures designed in different seismic intensity regions as well as with different height-to-width ratios. Two kinds of numerical models are adopted to simulate the seismic behavior of each frame, one with construction joint using the new proposed model and the other without construction joint using the conventional model. Results show that the influence of construction joint on the seismic behavior of reinforced concrete frame is strongly related to structural nonlinearity. It may increase the top displacement and the inter-story drift, change the inter-story drift distributions, and exacerbated the local reaction of key members. The influence of construction joint cannot be ignored for structures with low emergency capacity against major earthquake. Seismic design suggestions are proposed from the aspect of calculation analysis method.

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Seismic Behavior Factor of Moment Resisting Steel Frame-Steel Plate Shear Wall

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.638-640.1932 ◽

2014 ◽

Vol 638-640 ◽

pp. 1932-1936 ◽

Cited By ~ 1

Author(s):

Jian Hua Shao ◽

Qun Wu

Keyword(s):

Seismic Behavior ◽

Steel Plate ◽

Shear Wall ◽

Reduction Factor ◽

Steel Frame ◽

Steel Plate Shear Wall ◽

Behavior Factor ◽

Drift Ratio ◽

Story Drift ◽

Moment Resisting

The seismic behavior factor of moment resisting steel frame-steel plate shear wall under two different horizontal loading patterns was investigated according to the maximum inter-story drift ratio reaching 1/50. It could be achieved with the same calculated standard as the foreign codes and the determined behavior factor was compared with foreign research results. The method using the software SAP2000 to calculate seismic behavior factor according to the maximum inter-story drift ratio reaching 1/50 was presented and the specific example was used to elaborate the operating process. The seismic behavior factor R, the overstrength factor RΩ and the ductility reduction factor Rμ of 10-storey 3-span steel frame-steel plate shear wall under the inverted triangle load are respectively 6.07, 2.96 and 2.05. while they are respectively 7.2, 3.37 and 2.13 under the uniform load. Finally, it can be concluded that the economic and reasonable design goals are achieved for this structure.

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Seismic Behavior of a Class of Mixed Reinforced Concrete-Steel Buildings Subjected to Near-Fault Motions

Infrastructures ◽

10.3390/infrastructures6120172 ◽

2021 ◽

Vol 6 (12) ◽

pp. 172

Author(s):

Paraskevi K. Askouni ◽

George A. Papagiannopoulos

Keyword(s):

Reinforced Concrete ◽

Seismic Response ◽

Seismic Design ◽

Seismic Behavior ◽

Time History ◽

Steel Buildings ◽

Seismic Codes ◽

Near Fault ◽

Non Linear ◽

Story Drift

This paper investigates the seismic behavior of a class of mixed reinforced concrete–steel buildings. In particular, mixed buildings constructed by r/c (reinforced concrete) at their lower story(ies) and structural steel at their upper story(ies) are studied from the viewpoint of their wide application in engineering praxis. The need to investigate the seismic behavior for this type of mixed buildings arises from the fact that the existent literature is small and that modern seismic codes do not offer specific seismic design recommendations for them. To study the seismic behavior of mixed r/c-steel buildings, a 3-D numerical model is employed and five realistic r/c-steel mixed buildings are simulated. Two cases of the support condition, i.e., fixed or pinned, of the lowest steel story to the upper r/c one are examined. The r/c and steel parts of the mixed buildings are initially designed as separate structures by making use of the relevant seismic design guidelines of Eurocode 8, and then the seismic response of these buildings is computed through non-linear time-history analyses. The special category of near-fault seismic motions is selected in these time-history analyses to force the mixed r/c-steel buildings under study to exhibit a strong non-linear response. Seismic response indices in terms of inter-story drift ratio, residual inter-story drift ratio and peak floor absolute accelerations are computed. The maximum values of these indices are discussed by comparing the two aforementioned kinds of support conditions and checking the satisfaction of specific seismic performance limits. Conclusions regarding the expected seismic behavior of mixed r/c-steel buildings under near-fault seismic motions are drawn. Finally, the need to introduce specific design recommendations for mixed r/c-steel buildings in modern seismic codes is stressed.

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Mechanism of Frictional Mortar-Less Panel and its Application in Reinforcement Concrete Frame

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.894.82 ◽

2014 ◽

Vol 894 ◽

pp. 82-86

Author(s):

Xiao Hong Zhou

Keyword(s):

Finite Element ◽

Seismic Behavior ◽

Horizontal Displacement ◽

Frame Structure ◽

Rc Frame ◽

Base Shear ◽

Concrete Frame ◽

Rc Frame Structure ◽

Story Drift ◽

Considerable Benefit

In order to improve the seismic behavior of the reinforcement concrete frame, a frictional mortar-less panel (FMP) was researched. In this masonry, the bricks are built without mortar and the lateral capability is supported by the friction between bricks. FMP has less rigid in-plane contribution, and contribute mostly to the energy dissipation of structure. To investigate the seismic behavior of FMP, a simple finite element modeling method has been proposed and verified with ANSYS. After that, the FMP was infilled in a typical reinforcement concrete frame structure and a Taft wave has been applied to research on its seismic behavior. The horizontal displacement, story drift, acceleration and base shear/axial force of RC frame has been achieved, results showed the FMP has considerable benefit to the seismic behavior of RC frame structure and worth to be promoted.

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Seismic Behavior of Turbine-Generator Foundation under Strong Earthquake Action in Different Directions

Advances in Civil Engineering ◽

10.1155/2018/2506264 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10

Author(s):

Dong An ◽

Tie-jun Qu

Keyword(s):

Seismic Response ◽

Seismic Design ◽

Seismic Behavior ◽

Turbine Generator ◽

Maximum Displacement ◽

Scaled Model ◽

Seismic Displacement ◽

Limit Value ◽

Seismic Design Code ◽

Story Drift

In order to study seismic behavior of half-speed turbine-generator foundation under horizontal earthquake loading in different directions, the 1/10 scaled model was designed and fabricated. The rigid foundation of half-speed turbine-generator sets can be seen as a complex space frame system. The tests were conducted under eight earthquake waves in two directions separately. The loading directions were along the axis of longitudinal and transverse. The seismic response of displacement and story drift was investigated by a pseudodynamic test. The hysteresis behavior and crack propagation were analyzed. From the research, it is shown that the maximum displacement of the foundation under the earthquake of intensity 7 is 15.20 mm (longitudinal), basically in the range of elastic deformation. The seismic response of earthquake input in different directions is obviously different. Under the same earthquake input, the seismic displacement along the axis of longitudinal is larger than that of transverse. Under the rarely earthquake of intensity 8, the foundation still keeps good working condition. The maximum elastic-plastic story drift is 1/191 under the limit value 1/50 provided in the Code for Seismic Design of Buildings. The deformation capacity of the structure meets the requirements of the current seismic design code of China.

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Study on Seismic Behavior of Steel Frame with Different Brace Patterns

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.147.231 ◽

2011 ◽

Vol 147 ◽

pp. 231-235

Author(s):

Yun Zou ◽

Tian Qi Li ◽

Da Lin Zhang ◽

Peng Fei Zhang

Keyword(s):

Structural Design ◽

Seismic Behavior ◽

Time History ◽

Steel Frame ◽

Structural Stiffness ◽

Structural System ◽

History Analysis ◽

Story Drift ◽

Practical Engineering ◽

System Selection

In order to analyze dynamic characteristics of steel frame with different pattern braces, three structures with brace of X, V and Λ patterns were designed utilizing STS of PKPM software respectively. Sizes of main members were provided through designed. Based on structural design, time history analysis under different earth waves were made by using ANSYS to investigate the effects exerted from different pattern braces on structural stiffness. Results showed that three different braces played an important role in strengthening structural stiffness. Braces with V and Λ patterns had approximate properties. The story drift ratio and the overall torsion of three different braces met the requirements regulated by Chinese design codes. Conclusions might be useful in practical engineering design during structural system selection.

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Seismic Assessment and Rehabilitation of a RC Structure Under Mainshock-Aftershock Seismic Sequences Using Beam-Column Bonded CFRP Strategy

10.21203/rs.3.rs-1026929/v1 ◽

2021 ◽

Author(s):

Omid Karimzade Soureshjani ◽

Gholamreza Nouri

Keyword(s):

Structural Damage ◽

Seismic Behavior ◽

Aftershock Sequence ◽

Average Growth ◽

Seismic Sequences ◽

Weak Beam ◽

Drift Ratio ◽

Rc Structure ◽

Specific Performance ◽

Story Drift

Abstract A mainshock is usually accompanied by a group of ground motions. In many design codes, the effects of the seismic sequences have been neglected or underestimated. Aftershocks can increase structural damage or even cause failure. The current study evaluated the seismic behavior of a rehabilitated and as-built RC structure under real scaled mainshock-aftershocks using nonlinear analysis. Verification was done in two modes. The inter-story drift ratio, maximum residual, and relative displacements were studied. The seismic study of the as-built structure showed that the residual displacement grew, on average, more than 90% under the mainshock-aftershock sequence compared to the mainshock-only record. A beam-column bonded CFRP rehabilitation strategy using six layers of T-700 CFRP was chosen based on the specific performance level. The strategy showed the ability to transfer the plastic strain from the columns to the beams, which could be considered as a change from a weak column-strong beam concept to a strong column-weak beam concept. Compared to the as-built structure under the seismic sequences, the rehabilitated structure showed an average growth of 78% in the first-story drift ratio, which was significant. Unlike the as-built structure, seismic sequences caused no growth drift in the rehabilitated structure. It also was observed that the ratio of aftershock PGA to mainshock PGA could have an intensive effect on the seismic behavior of both rehabilitated and as-built structures.

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Research of the Influence of Dual Functional Hysteretic Dampers on Seismic Behavior of Structure with Big Openings

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.482.217 ◽

2013 ◽

Vol 482 ◽

pp. 217-220

Author(s):

Yan Liu ◽

Yan Li ◽

Hui Ling Wang

Keyword(s):

Energy Dissipation ◽

Seismic Behavior ◽

Vibration Mode ◽

Plastic State ◽

Elastic State ◽

Rare Occurrence ◽

Natural Period ◽

Dual Functional ◽

Story Drift ◽

Hysteretic Dampers

The dissertation shows the formation and failure characteristic of the dual functional hysteretic dampers. SAP2000 was used to analyze the natural period of vibration and vibration mode of structures, the story drift under frequent earthquake and rare occurrence earthquake with different arrangements of dampers and the energy dissipation of dampers. The results show that dual functional hysteretic dampers keep elastic state under frequent earthquake while enter plastic state before the structure under rare occurrence earthquake.

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Seismic Behavior of RC Moment Resisting Structures with Concrete Shear Wall under Mainshock-aftershock Seismic Sequences

10.21203/rs.3.rs-739616/v1 ◽

2021 ◽

Author(s):

Omid Karimzade Soureshjani ◽

Ali Massumi

Keyword(s):

Seismic Behavior ◽

Shear Wall ◽

Relative Displacement ◽

Structure Model ◽

Residual Displacement ◽

Significant Growth ◽

Seismic Sequences ◽

Drift Ratio ◽

Story Drift ◽

Moment Resisting

Abstract A structure may subject to several aftershocks after a mainshock. In many seismic design provisions, the effect of the seismic sequences is not directly considered or underestimated. This paper studies the seismic behavior of RC moment-resisting structures with concrete shear wall under seismic sequences. Two three-dimensional structures of short and medium height were designed and analyzed. The former models were studied under a group of real mainshock-aftershock seismic sequences. The models were loaded and designed according to the fourth edition of the Iranian seismic code of standard no. 2800 and ACI-318 respectively. Furthermore, the non-linear dynamic time-history finite element analysis of models was performed via the explicit method. The parameters of maximum displacement, inter-story drift ratio, residual displacement, and finally the effect of the ratio of aftershock acceleration to mainshock acceleration were investigated and assessed. Due to the high lateral stiffness of shear walls, parallel with the complete elastic behavior, aftershocks cause no growth in inter-story drift ratio and relative displacement in the short structure model. In contrast, compared to the structure under the solely mainshock, the medium height structure model under seismic sequences showed significant growth in the amount of relative displacement (even more than 50% growth), inter-story drift ratio, plastic strain, and residual displacement (almost 30% growth). Furthermore, unlike the moment-resisting frame structures, models showed no significant growth in the drift ratio with the height. Assessments indicated that the ratio of aftershock to mainshock acceleration is a determinative parameter in structural behavior under seismic sequences.

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Seismic Behavior of Concentrically Braced Steel Frames with Out-of-Plane Offset Irregularity

The Open Civil Engineering Journal ◽

10.2174/1874149501711010485 ◽

2017 ◽

Vol 11 (1) ◽

pp. 485-495 ◽

Cited By ~ 1

Author(s):

Amin Mohebkhah ◽

Marzieh Akefi

Keyword(s):

Seismic Design ◽

Seismic Behavior ◽

Steel Frames ◽

Design Parameters ◽

Braced Frames ◽

Concentrically Braced Frames ◽

Overstrength Factor ◽

Concentrically Braced ◽

Out Of Plane ◽

Story Drift

Braced steel frames are sometimes designed with out-of-plane shifted bracing members on the first story due to architectural or functional considerations. Such frames are classified and designated as frames having the Type-4 horizontal structural irregularity entitled “frames with out-of-plane offset irregularity” as per theMinimum Design Loads for Building and Other Structures(ASCE 7-10). The purpose of this study is to investigate the nonlinear seismic behavior of ordinary steel concentrically braced frames with out-of-plane offset irregularity and evaluate their seismic design parameters. To this end, two 3-story and 6-story three-dimensional ordinary concentrically braced frames (OCBFs) with and without out-of-plane offset of one of the vertical elements on the first story were considered (i.e. irregular and regular configurations). The seismic design parameters considered in this study includes: frame overall overstrength factor, column overstrength factor and the inelastic dynamic inter-story drift demands. Nonlinear time-history dynamic analysis of the frames showed that overall overstrength factor of the low- and mid-rise irregular frames studied in this research is lower than that of the regular ones. Moreover, it was found that theSeismic Provisionsprescribed overstrength factor (i.e. Ωo=2.0) to amplify columns axial seismic forces in OCBFs is not conservative for the studied regular frames’ columns as well as the columns in the vicinity of the shifted bracing members on the first story of the irregular frames. Also, it was shown that the studied low- and mid-rise regular and irregular concentrically braced frames experience greater inter-story drift demands than predicted by the amplified elastic analysis proposed in the codes.

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