• Title/Summary/Keyword: design provisions

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Critical review of the EC8 design provisions for buildings with eccentric braces

  • Bosco, Melina;Marino, Edoardo M.;Rossi, Pier Paolo
    • Earthquakes and Structures
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    • v.8 no.6
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    • pp.1407-1433
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    • 2015
  • The objections raised by researchers to the design provisions reported in Eurocode 8 make the efficient seismic performance of the eccentrically braced structures designed according to this code unlikely. Given the rationality and the number of the objections, this paper aims to summarize the criticism of researchers and report the opinion of the Authors. The objections raised to the design procedure of eccentrically braced structures regard aspects common to the design of steel structures and aspects specifically related to the design of eccentrically braced structures. The significance of these objections is also shown by means of exemplary cases.

Quasi-Static Tests on SRC Composite Columns (SRC 합성교각의 준정적 실험)

  • Shim, Chang-Su;Chung, Young-Soo;Jung, In-Keun;Min, Jin;Han, Jung-Hun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.299-302
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    • 2005
  • This study deals with the quasi-static tests on steel reinforced concrete composite columns with single embedded steel or multiple members. For the design of bridge piers, the composite section needs to have low steel ratio for cost savings because the dimension of the pier section is usually large. There is lack of design guidelines for these composite columns with low steel ratio, but the design provisions for the normal reinforced concrete column can be used for the design because of the low steel ratio. It is necessary to provide the design provisions in terms of the strength limit state and seismic performance by the detail requirements on the longitudinal steel and the transverse steel. The test parameters in this study were determined considering the current design provisions on RC columns. Through the quasi-static tests, the seismic performance of the composite columns were discussed.

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Review of Code Provisions on Seismic Design of Fire Protection System (소방설비 내진설계에 관한 각국 기준 비교 연구)

  • Lee, Hyun-Jin;Shin, Yi-Chul;Lee, Jae-Young;Seo, Dong-Goo;Han, Byung-Chan;Kim, Jae-Hwan;Kwon, Young-Jin
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.238-241
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    • 2008
  • In this paper, provisions related with the seismic design and equipments of fire protection system are being considered. The provisions from various international codes on seismic design fire protection system were reviewed. The codes, reviewed are, Japanese code, NFPA guideline and Korean code. It is noted that all the codes excepted to korean code consider earthquake effect to evaluate seismic forces and behaviors. But, korean provision are not covered in seismic response in all. A brief description on limitations in korean code is also presented.

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Optimum Reliablity Based Design Criteria for Bridge Cassion Foundation (교량케이슨기초의 최적신뢰성 설계 규준)

  • 손용우;신형우;이증빈;정철원
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1992.10a
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    • pp.79-89
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    • 1992
  • This study is directed to propose a stability analysis and Design Criteria for Bridge Caisson foundations, with Could possibly replace the traditionals W.S.D. provisions of the Current Code, based on the FBOR(Load Factors based on optimum Reliability). The optimum reliability indices(Vertical bearing Capacity : $\beta$opt : 3.19, Lateral bearing Capacity : $\beta$opt= 3.15(ordinary), $\beta$opt : 2.93 (earthquake), Shearing resistance Capacity ; $\beta$opt : 2.87) are Selected as optimal Values Considering our practice base on the Calibration with the current Bridge Caisson foundation design Safety provisions, Load and resistance factors are measure by Using the proposed uncertainties and the Selected optimum reliability indices. furthermore, a set of nominal safety factors are proposed for the U.S.D. design provisions.

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The design of reinforced concrete beams for shear in current practice: A new analytical model

  • Londhe, R.S.
    • Structural Engineering and Mechanics
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    • v.31 no.2
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    • pp.225-235
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    • 2009
  • The present paper reviews the shear design (of reinforced concrete beam) provisions of four different national codes and proposes a new but simplified shear strength empirical expression, incorporating variables such as compressive strength of concrete, percentage of longitudinal and vertical steel/s, depth of beam in terms of shear span-to-depth ratio, for reinforced concrete (RC) beams without shear reinforcement. The expression is based on the experimental investigation on RC beams without shear reinforcement. Further, the comparisons of shear design provisions of four National codes viz.: (i) IS 456-2000, (iii) BS 8110-1997, (iv) ACI 318-2002 (v) EuroCode-2-2002 and the proposed expression for the prediction of shear capacity of normal beam/s, have been made by solving a numerical example. The results of the numerical example worked out suggest that there is need for revision in the shear design procedure of different codes. Also, the proposed expression is less conservative among the IS, BS & Eurocode.

Development of the Damping Coefficients for Weak and Moderate Earthquake Ground Motions

  • Kim, Myeong-Han
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.5
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    • pp.1-6
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    • 2008
  • Most of seismic design code provisions provide the design response spectra for defining design earthquake ground motions. The design spectra in the code provisions generally come under the 5% of critical damping value, which corresponds to the responses of common structure under the design earthquake. Energy dissipation devices and seismic isolation systems became more popular and the design response spectra at higher damping levels are required. Damping coefficients can be effectively used in conversion of 5%-damped design spectra into other damping levels. These coefficients in the current seismic design code provisions are based on the strong ground motion records. Since the weak and moderate earthquake data have different characteristics from those of strong earthquake data, the application of these coefficients should be investigated in the weak and moderate earthquakes zones. In this study, damping coefficients based on the weak and moderate ground motions were developed and compared to those of current seismic design code provisions.

Investigation of design methods in calculating the load-carrying capacity of mortise-tenon joint of timber structure

  • Hafshah Salamah;Seung Heon Lee;Thomas H.-K. Kang
    • Earthquakes and Structures
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    • v.25 no.5
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    • pp.307-323
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    • 2023
  • This study compares two prominent design provisions, National Design Specification (NDS) and Eurocode 5, on load-carrying capacity calculations and failure analysis for mortise-tenon joints. Design procedures of double-shear connection from both provisions were used to calculate load-carrying capacity of mortise-tenon joints with eight different bolt sizes. From this calculation, the result was validated using finite element analysis and failure criteria models. Although both provisions share similar failure modes, their distinct calculation methods significantly influence the design load-carrying capacity values. Notably, Eurocode 5 predicts a 6% higher design load-carrying capacity for mortise-tenon joints with varying bolt diameters under horizontal loads and 14% higher under vertical loads compared to NDS. However, the results from failure criteria models indicate that NDS closely aligns with the actual load-carrying capacity. This indicates that Eurocode 5 presents a less conservative design and potentially requires fewer fasteners in the final timber connection design. This evaluation initiates the potential for the development of a wider range of timber connections, including mortise-tenon joints with wooden pegs.

Equivalent lateral force method for buildings with setback: adequacy in elastic range

  • Roy, Rana;Mahato, Somen
    • Earthquakes and Structures
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    • v.4 no.6
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    • pp.685-710
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    • 2013
  • Static torsional provisions employing equivalent lateral force method (ELF) require that the earthquake-induced lateral force at each story be applied at a distance equal to design eccentricity ($e_d$) from a reference resistance centre of the corresponding story. Such code torsional provisions, albeit not explicitly stated, are generally believed to be applicable to the regularly asymmetric buildings. Examined herein is the applicability of such code-torsional provisions to buildings with set-back using rigid as well as flexible diaphragm model. Response of a number of set-back systems computed through ELF with static torsional provisions is compared to that by response spectrum based procedure. Influence of infill wall with a range of opening is also investigated. Results of comprehensive parametric studies suggest that the ELF may, with rational engineering judgment, be used for practical purposes taking some care of the surroundings of the setback for stiff systems in particular.

Modal rigidity center: it's use for assessing elastic torsion in asymmetric buildings

  • Georgoussis, George K.
    • Earthquakes and Structures
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    • v.1 no.2
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    • pp.163-175
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    • 2010
  • The vertical axis through the modal center of rigidity (m-CR) is used for interpreting the code torsional provisions in the design of eccentric multi-story building structures. The concept of m-CR has been demonstrated by the author in an earlier paper and the particular feature of this point is that when the vertical line of the centers of mass at the floor levels is passing through m-CR, minimum base torsion is developed. For this reason the aforesaid axis is used as reference axis for implementing the code provisions required by the equivalent static analysis. The study examines uniform mixed-bent-type multistory buildings with simple eccentricity, ranging from torsionally stiff to torsionally flexible systems. Using the results of a dynamic response spectrum analysis as a basis for comparisons, it is shown that the results of the code static design are on the safe side in torsionally stiff buildings, but unable to predict the required strength of bents on the stiff side of systems with a predominantly torsional response. Suggestions are made for improving the code provisions in such cases.

Significant Changes in the Seismic Design Provisions of the 2005 KBC (KBC 2005 내진설계 주요 개정사항)

  • Chung, Kwang-Rhang;Yoo, Byoung-Eok
    • Journal of the Korean Professional Engineers Association
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    • v.38 no.5
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    • pp.5-9
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    • 2005
  • The seismic design provisions of the 2005 KBC has been based on the 2000 IBC and has considered the building code situations in Korea. There are site ground motion, soil class, seismic design category in the significant changes of the 2005 KBC. In the case of soft soil condition, the response spectrum acceleration of the 2005 KBC is larger than that of previous code. To reduce the seismic force of the 2005 KBC, it need to introduce the eqrthauke force resisting system with high ductility.

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