Seismic Performance of a Base Isolated Structure by Shake Table Tests

This paper presents the findings of a research that focused on the seismic performance of masonry-infilled, nonductile, RC frames. This research has resulted in improved analytical methods and effective retrofit techniques to assess and enhance the performance of these structures. The methods were validated by a series of quasi-static tests conducted on one-story frame specimens as well as shake-table tests conducted on two 2/3-scale, three-story, two-bay, masonry-infilled, RC frames. This paper focuses on the observations from the shake-table tests and the further insight gained from a numerical study conducted with finite element models. The first shake-table test specimen had no retrofit measures, and the second had infill walls in the first and second stories strengthened with Engineered Cementitious Composite (ECC) and Fiber Reinforced Polymeric (FRP) overlays, respectively. The tests demonstrated the effectiveness of the retrofit measures. Finite element models that combine smeared and discrete cracks have been used in a numerical study to examine the benefits of the ECC retrofit and the influence of the capacity of the shear dowels that connect an ECC overlay to the RC beams on structural performance. It has been shown that these shear dowels play a critical role in enhancing both the strength and ductility of a retrofitted structure.

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Physical Model Study of the Seismic Performance of Highway Embankments with and without Geotextile

Journal of Earthquake and Tsunami ◽

10.1142/s1793431117500038 ◽

2017 ◽

Vol 11 (02) ◽

pp. 1750003 ◽

Cited By ~ 1

Author(s):

Ayşe Edinçliler ◽

Yasin Sait Toksoy

Keyword(s):

Seismic Performance ◽

Structural Safety ◽

Shake Table ◽

Geosynthetic Reinforcement ◽

Shake Table Tests ◽

Seismic Safety ◽

Dynamic Motion ◽

Slope Inclination ◽

Highway Embankments ◽

Motion Characteristics

In order to ensure structural safety and integrity in earthquake conditions, it may be useful or even necessary to increase the seismic safety of the highway embankments with reinforcement inclusions. The inclusion of geosynthetics in highway embankments may provide an additional tensile strength and durability to construct more stable and earthquake resistant embankments. In this study, the contributions of the primary factors as inclusion of the geotextile reinforcement, slope inclination and dynamic motion characteristics affecting the seismic performance of the highway embankments are evaluated. Shake table models of the unreinforced and geosynthetic reinforced highway embankments with different slope inclinations are designed. An extensive series of shake table tests were performed under dynamic motions with different predominant frequencies. Test results revealed that inclusion of geotextiles in the embankment model causes deamplification of the transmitted accelerations traveling through the reinforced embankment models. Thus, the geosynthetic reinforcement successfully enhances the seismic performance and mitigates earthquake-related hazards. Contribution of this study to the literature is that the efficiency of the geosynthetic reinforcement by means of energy absorption properties is highly dependent on the dynamic motion characteristics but less dependent to the degree of slope inclination.

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Seismic Performance of Stone Masonry Buildings Used in the Himalayan Belt

Earthquake Spectra ◽

10.1193/091711eqs228m ◽

2013 ◽

Vol 29 (4) ◽

pp. 1159-1181 ◽

Cited By ~ 11

Author(s):

Qaisar Ali ◽

Akhtar Naeem Khan ◽

Mohammad Ashraf ◽

Awais Ahmed ◽

Bashir Alam ◽

...

Keyword(s):

Seismic Performance ◽

Cost Effective ◽

Stone Masonry ◽

Shake Table ◽

Masonry Buildings ◽

Masonry Structures ◽

Limit States ◽

Shake Table Tests ◽

Capacity Curves ◽

Rubble Stone Masonry

Rubble-stone masonry structures are found abundantly in the Asian countries along the Himalayan range. Such structures are usually constructed in dry-stone masonry or are constructed in mud mortar, which makes them susceptible to damage and collapse in earthquakes. In order to study the seismic behavior of these structures, dynamic shake table tests on three reduced-scale rubble-stone masonry models were conducted. The models comprised a representative school building, a residential building, and a model incorporating simple cost-effective features in the form of horizontal and vertical reinforced concrete elements. This paper presents the results of shake table tests carried out on rubble-stone masonry buildings including: damage pattern, capacity curves, damage limit states, and response modification factors of these structures. Test data indicates that seismic performance of rubble-stone masonry structures can be significantly improved by incorporating cost-effective features such as vertical members and relatively thin horizontal bands.

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Shake Table Tests of a Novel Low-rise Bolt-Assembled Precast Concrete Sandwich Wall Panel Structure

10.21203/rs.3.rs-1212295/v1 ◽

2022 ◽

Author(s):

Feng Xiong ◽

Wen Chen ◽

Qi Ge ◽

Jiang Chen ◽

Yang Lu

Keyword(s):

Seismic Performance ◽

Precast Concrete ◽

High Strength ◽

Shake Table ◽

Wall Panel ◽

Base Shear ◽

Earthquake Excitation ◽

Shake Table Tests ◽

Sandwich Wall ◽

Sandwich Wall Panel

Abstract A novel low-rise bolt - assembled precast concrete sandwich wall panel structure for rural residential houses was proposed, in which the connections between wall and wall, and wall and floor were connected by high strength bolts and steel plates. The bolt joints can be easily installed and disassembled. They are replaceable to make the precast structure demountable and reassembled. All the components are connected together by the novel bolted connectors. This paper presents the shake-table tests of a full-scale two-story bolt-assembled precast concrete sandwich wall building. The results indicated that the proposed structural system had good seismic performance and remained in the elastic stage with no damage after 9-degree rare earthquake excitation for the Model-1. The Model-2 exhibited excellent capacity and performed satisfactorily under the excitation up to 0.8 g. Cracks were observed at the wall openings and the base of walls and columns, which was similar to that of a cast-in-situ structure. The damage statuses were mainly light damage and moderate damage. The bolt connection joints were not anti-seismic weak places and had good seismic performance. Equivalent base shear method is suitable for estimating the seismic demand of the proposed precast concrete sandwich wall panel structure.

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Seismic Performance of Chlorinated Polyvinyl Chloride Sprinkler Pipes

Earthquake Spectra ◽

10.1193/091217eqs181m ◽

2018 ◽

Vol 34 (3) ◽

pp. 1497-1513 ◽

Cited By ~ 1

Author(s):

Jochen Carl ◽

Zheng Peng ◽

Harold Magistrale

Keyword(s):

Numerical Simulations ◽

Polyvinyl Chloride ◽

Seismic Performance ◽

Fire Protection ◽

Bending Strength ◽

National Fire Protection Association ◽

Acceptable Level ◽

Shake Table ◽

Shake Table Tests ◽

Pipe Bending

A major concern about chlorinated polyvinyl chloride (CPVC) pipes is the large swing of branch lines during earthquake-induced motions. National Fire Protection Association (NFPA) 13 defines spacing requirements for braces and restraints, based on pipe-bending strength, but does not limit the swing. Shake table tests and numerical simulations show that the swing of CPVC branch lines can be limited to an acceptable level if the ends are braced and the spacing of restraints follows the NFPA 13 requirements for CPVC, or if restraint spacing is reduced to about half of that currently allowed in NFPA 13.

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Shake Table Tests to Measure the Dynamic Performance of Geotextile-reinforced Embankment

Periodica Polytechnica Civil Engineering ◽

10.3311/ppci.10540 ◽

2017 ◽

Cited By ~ 1

Author(s):

Ayşe Edinçliler ◽

Yasin S. Toksoy

Keyword(s):

Cyclic Loading ◽

Seismic Performance ◽

Dynamic Load ◽

Dynamic Performance ◽

Time History ◽

Shake Table ◽

Shake Table Tests ◽

Highway Embankments ◽

Highway Embankment

Using geosynthetics in highway embankments can reduce theimpact of hazardous earthquakes by transmitting less excitationto improve the seismic performance. This study uses a 1-greduced scale (1/50) approach and subjects the model embankmentto an earthquake time history as well as several levelsof uniform cyclic loading. The main focus of comparison isbetween an unreinforced embankment and a one, reinforcedwith two levels of geosynthetics material. Results reveal thatgeotextile reinforced highway embankment models performmuch better under the applied motions. Larger amplitudes causemore severe deformations as a result of the increased dynamicloads. It is also revealed that the effectiveness of the geosyntheticsis dominated by the seismic frequency. Deamplificationis observed within the geotextile reinforced embankment but thedegree of deamplification is highly depended on the predominantfrequency of the dynamic load.

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