Seismic performance evaluation of a 34‐story steel building retrofitted with response modification elements

Weng, Yuan‐Tao; Tsai, Keh‐Chyuan; Chen, Pei‐Ching; Chou, Chung‐Che; Chan, Ya-Ran; Jhuang, Sheng‐Jhih; Wang, Yung-Yu

doi:10.1002/eqe.865

Cited by 8 publications

(8 citation statements)

References 11 publications

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“…A research [16] investigating the seismic demands for the existing and retrofitted buildings subjected to design-based and maximum-considered earthquakes confirmed the effectiveness of those retrofitting structural elements. Owing to the financial difficulties faced by the developer, the construction of the original hotel was suspended for 10 years.…”

Section: Introductionmentioning

confidence: 70%

“…Specimens were tested until connection failure occurred or limitations of the test setup were reached. Although the existing connection specimen before rehabilitation shows good performance, exceeding seismic demands (1-1.5% drift) obtained from inelastic time history analyses of the steel frame [16], it fails to satisfy a current ductility requirement (4% drift) prescribed in AISC seismic provisions [13]. Minor whitewash flaking, indicating beam yield, was observed in the beam flange near the groove weld at an inter-story drift of 0.75%.…”

Section: Test Setup and Loading Protocolmentioning

confidence: 99%

See 1 more Smart Citation

Seismic rehabilitation performance of steel side plate moment connections

Chou¹,

Tsai²,

Wang³

et al. 2009

Earthq Engng Struct Dyn

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Moment connections in an existing steel building located in Kaohsiung, Taiwan were rehabilitated to satisfy seismic requirements based on the 2005 AISC seismic provisions. Construction of the building was ceased in 1996 due to financial difficulties and was recommenced in 2007 with enhanced connection performance. Steel moment connections in the existing building were constructed by groove welding the beam flanges and bolting the beam web to the column. Four moment connections, two from the existing steel building, were cyclically tested. A non-rehabilitated moment connection with bolted web-welded flanges was tested as a benchmark. Three moment connections rehabilitated by welding full-depth side plates between the column face and beam flange inner side were tested to validate the rehabilitation performance. Test results revealed that (1) the non-rehabilitated existing moment connection made by in situ welding process prior to 1996 had similar deformation capacity as contemporary connection specimens made by laboratory welding process, (2) all rehabilitated moment connections exhibited excellent performance, exceeding a 4% drift without fractures of beam flange groove-welded joints, and (3) presence of the full-depth side plates effectively reduced beam flange tensile strain near the column face by almost half compared with the non-rehabilitated moment connection. The connection specimens were also modeled using the non-linear finite element computer program ABAQUS to further confirm the effectiveness of the side plate in transferring beam moments to the column and to investigate potential sources of connection failure. A design procedure was made based on experimental and analytical studies. Figure 15. Side plate strain comparisons between test and finite element model: (a) Specimen SP2 and (b) Specimen SP3.fillet welds between the shear plate and the beam web, and (3) continuity plates in the box column are as thick as the beam flange. Owing to the limited test data available for this type connection, the box column width should be less than 2.8 times the beam width, and the column thickness should be larger than 1.25 times the beam flange thickness to maintain locally stiff column relative to the beam. The step-by-step design procedure is summarized as follows:Step 1: Select a side plate length, L s , based on the beam dimension and strength (Equation (4)).Step 2: Compute the beam plastic moment at the column face using a strain hardening factor, , of 1.5 (Equation (1)).Step 3: Use Equation (5) to compute the side plate thickness with a rehabilitated beam moment capacity-demand ratio, , of 1.11-1.16.Step 4: Check for strong column-weak beam condition (Equation (6)). CONCLUSIONSFour exterior moment connection specimens, each composed of an ASTM A572 Gr. 50 welded box column and an ASTM A36 wide-flange beam, were cyclically tested. Two bolted web-welded flange moment connections were removed from the existing steel building in Taiwan. One of the connections was rehabilitated by welding two side plates between t...

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Section: Introductionmentioning

confidence: 70%

Section: Test Setup and Loading Protocolmentioning

confidence: 99%

Seismic rehabilitation performance of steel side plate moment connections

Chou¹,

Tsai²,

Wang³

et al. 2009

Earthq Engng Struct Dyn

Self Cite

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“…The effects of the number of modes incorporated into the MMS method were not studied extensively in the previous study (Weng et al 2009). It is worth noting that only two modes were sufficient for the three SAC-LA buildings to meet the 90% effective mass requirements.…”

Section: Effect Of the Number Of Vibration Modesmentioning

confidence: 99%

“…Figure 11 shows the typical structural framing plan of this 34-story building. The details of this high-rise building can be found in the reference (Weng et al 2009). In that study, only the first three modes constituting 84% effective mass were considered in the MMS procedure.…”

Section: Effect Of the Number Of Vibration Modesmentioning

confidence: 99%

A Ground Motion Scaling Method considering Higher-Mode Effects and Structural Characteristics

Weng

Tsai

Chan³

2010

Earthquake Spectra

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As nonlinear response history analysis (NLRHA) becomes a frequently used procedure for the seismic demand evaluation of multistory buildings, it becomes increasingly important to develop a ground motion scaling method which properly includes the dominating modes in the seismic demand estimates. This paper proposes a multimode ground motion scaling (MMS) method, which applies the square root of the sum of the squares (SRSS) or complete quadratic combination (CQC) rule in computing peak seismic demands. The aim is to minimize the weighted sum of the square differences between the spectral responses of a given ground motion and the design response spectrum for the first few modes. Using four case studies, this paper compares the effectiveness of the MMS method with the other common scaling procedures. It is illustrated that the MMS method is effective in reducing the scatter in the peak seismic demands computed from both the response spectral analysis (RSA) and the NLRHA. Recommendations for selecting the ground motion records for the application of MMS method are also provided.

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“…A real‐time hybrid online test 14–18 can allow for velocity‐dependency, but the current state‐of‐the‐practice has not reached the level of reliable applications particularly for large‐scale tests. A quasi‐static test in an in situ condition is notable, too, but to find a test specimen requires fortuity 19. In reference to those pros and cons, a shaking table test using alarge‐scale shaking table was adopted 20.…”

Section: Introductionmentioning

confidence: 99%

Seismic resistance capacity of beam–column connections in high‐rise buildings: E‐Defense shaking table test

Chung

Nagae

Matsumiya

et al. 2010

Earthq Engng Struct Dyn

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A series of E-Defense shaking table tests are conducted on a large-scale test specimen that represents a high-rise steel building. Two types of connections featuring the connection details commonly used in 1970s, in the early days of high-rise construction in Japan, are adopted: the field-welded connection consisting of welded unreinforced flanges and a bolted web type, and the shop-welded connection in which the flanges and web are all-welded to the column flange in the shop. To examine the seismic capacity of a total of 24 beam-to-column connections of the specimen, particularly when it is subjected to long-period ground motion characterized not so much by large amplitude as by very many cycles of repeated loading, the test specimen is shaken repeatedly until the connections fractured. The test results indicate that a few of the field-welded connections fractured from the bottom flange weld boundary in a relatively small cumulative rotation primarily due to the difficulties in ensuring the welding and inspection performance in the actual field welding. The shop-welded connections are able to sustain many cycles of plastic rotation, with an averaged cumulative plastic rotation of 0.86 rad. Two shop-welded connections exhibit ductile fractures but only after experiencing many cycles. The presence of RC floor slabs promotes the strain concentration at the toe of the weld access hole in the bottom flange by at least twice compared with the case without the slab, which had resulted in a decrease in the cumulative plastic rotation by about 50%. 606 Y.-L. CHUNG ET AL.existing high-rise buildings, long-period ground motions could demand significantly larger energy dissipation than the design waves commonly used in the Japanese seismic design, especially to beam-to-column connections, with anticipated cumulative deformations amounting to several to 10 times larger than those expected for the design waves [4].The 1994 Northridge and the 1995 Hyogoken-Nanbu earthquakes tested the seismic performance of steel moment frames, which have been widely used in seismic design in the U.S. and Japan. In the earthquakes, severe damage was observed in the welded unreinforced flanges and bolted web connections (WUF-B) [5][6][7]. A number of Japanese high-rise buildings built in the 1970s had also adopted WUF-B connections, although connection details were similar but not exactly identical to those damaged in the earthquakes.Considering those circumstance, the writers decided to experimentally evaluate the seismic performance of the high-rise buildings subjected to long-period ground motions. Several alternatives were considered for the type of testing, i.e. a shaking table test, a hybrid online test, and a quasi-static loading test. In all cases, the test specimen had to preserve a realistic scale since the behavior involving serious damage such as fractures was to be simulated. A substructure-based hybrid online test [8][9][10][11][12][13] was appealing to conduct such a test, but quasi-static loading was not necessarily preferable a...

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Seismic performance evaluation of a 34‐story steel building retrofitted with response modification elements

Cited by 8 publications

References 11 publications

Seismic rehabilitation performance of steel side plate moment connections

Seismic rehabilitation performance of steel side plate moment connections

A Ground Motion Scaling Method considering Higher-Mode Effects and Structural Characteristics

Seismic resistance capacity of beam–column connections in high‐rise buildings: E‐Defense shaking table test

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