• Title/Summary/Keyword: regularity in elevation

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Approximate methods to evaluate storey stiffness and interstory drift of RC buildings in seismic area

  • Caterino, N.;Cosenza, E.;Azmoodeh, B.M.
    • Structural Engineering and Mechanics
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    • v.46 no.2
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    • pp.245-267
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    • 2013
  • During preliminary design of a RC building located in a seismic area, having quick but reliable analytical measurement of interstory drifts and storey stiffnesses might be helpful in order to check the fulfillment of damage limit state and stiffness regularity in elevation required by seismic design codes. This paper presents two approximate methods, strongly interrelated each other, and addressed to achieve each of these two purposes for frame buildings. A brief description of some already existing methods addressed to the same aims is included to compare the main differences in terms of general approaches and assumptions. Both new approximate methods are then applied to 9 'ideal' frames and 2 'real' buildings designed according to the Italian seismic code. The results are compared with the 'exact' values obtained by the code-based standard calculation, performed via FEM models, showing a satisfactory range of accuracy. Compared with those by the other methods from literature, they indicate the proposed procedures lead to a better approximation of the objective structural parameters, especially for those buildings designed according to the modern 'capacity design' philosophy.

A study on the effects of vertical mass irregularity on seismic performance of tunnel-form structural system

  • Mohsenian, Vahid;Nikkhoo, Ali
    • Advances in concrete construction
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    • v.7 no.3
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    • pp.131-141
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    • 2019
  • Irregular distribution of mass in elevation is regarded as a structural irregularity by which the modes with high energy levels are excited and in addition, it can lead the structure to withstanding concentration of nonlinear deformations and consequently, suffer from unpredictable local or global damages. Accordingly, with respect to the lack of knowledge and insight towards the performance of concrete buildings making use of tunnel-form structural system in seismic events, it is of utmost significance to assess seismic vulnerability of such structures involved in vertical mass irregularity. To resolve such a crucial drawback, this papers aims to seismically assess vulnerability of RC tunnel-form buildings considering effects of irregular mass distribution. The results indicate that modal responses are not affected by building's height and patterns of mass distribution in elevation. Moreover, there was no considerable effect observed on the performance levels under DBE and MCE hazard scenarios within different patterns of irregular mass distribution. In conclusion, it appears that necessarily of vertical regularity for tunnel-form buildings, is somehow drastic and conservative at least for the buildings and irregularity patterns studied herein.

A Study on the Performance Elevation Methods of Next Generation Railway Freight Vehicles (한국형 고속열차를 이용한 고속선-기존선 연결구간의 속도향상 가능성에 관한 연구)

  • Ham Y.S.;Hong J.S.;Oh T.Y.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.12-15
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    • 2005
  • In April 1, 2004, age of high-speed railway was opened to korea railroad. The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail farce, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, examined speed elevation possibility use the korean style high speed railway vehicle for reduce the running time of high-speed railway between high speed line and conventional line.

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A Study on the Dom-Ino system and Proportion in Le Corbusier′s Houses (Le Corbusier의 주거건축에 나타나는 Dom-Ino시스템과 비례체계에 관한 연구)

  • Cho Sung-Hyun;Kim Chul-Kyu
    • Journal of the Korean housing association
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    • v.15 no.4
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    • pp.107-115
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    • 2004
  • The purpose of this paper is to study on the architectural value in Dom-Ino system. Dom-Ino system by Le Corbusier is a structural system for effective production in terms of physical reproductivity and a modeling system from the view of formal composition. It creates planar grid with a fixed ratio, manipulates the user group, and becomes the basic construction method. Form comes out of geometrical proportion system, and grid-based plan provides regularity and order to elevation planning. Production requires standardization. Indoor space is maintained by uniformed and integrated service facilities. Dom-Ino system was a transitional step of the Modulor system which was created by Le Corbusier in 1945 and composes of and equivalent proportional system. The fact that the numerical proportion system is the one of appropriate design methods implys a progressive concept that architectural configurations are controlled by the technology of that time. And also the system is one of the object type of Corbusier's housing architecture.

Effectiveness of different standard and advanced pushover procedures for regular and irregular RC frames

  • Landi, Luca;Pollioa, Bernardino;Diotallevi, Pier Paolo
    • Structural Engineering and Mechanics
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    • v.51 no.3
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    • pp.433-446
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    • 2014
  • The purpose of the research presented in this paper was to investigate the effectiveness of several conventional, multi-modal and adaptive pushover procedures. In particular, an extensive numerical study was performed considering eight RC frames characterized by a variable number of storeys and different properties in terms of regularity in elevation. The results of pushover analyses were compared with those of nonlinear dynamic analyses, which were carried out considering different earthquake records and increasing values of earthquake intensity. The study was performed with reference to base shear-top displacement curves and to different storey response parameters. The obtained results allowed a direct comparison between the pushover procedures, which in general were able to give a fairly good estimate of seismic demand with a tendency to better results for lower frames. The advanced procedures, in particular the multi-modal pushover, provided an improvement of the results, more evident for the irregular frames.

A Study on the Altitude Restrictions of Obstructions outside Airport Obstacle Limitation Surfaces of Korea (한국의 비행장 장애물 제한구역 밖의 장애물이 항공안전에 미치는 영향에 관한 연구)

  • Yang, Han-Mo;Kim, Byung-Jong;Kim, Do-Hyun
    • Journal of Korean Society of Transportation
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    • v.23 no.6 s.84
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    • pp.41-53
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    • 2005
  • The effective utilization of an airport is considerably influenced by natural features and man-made structures inside and outside its boundary. These obstacles affect the airspace available for approaches and departures and the weather minima which dictates the necessary weather conditions for aircraft to be allowed to take-off or land. Certain areas of the airspace near airports must be regarded as the integral parts of the airport system. The availability of the required airspace is as important as are the runway and their associated strips to the safe and efficient use of the airport. For these reasons, ICAO and the member states have established the standards regarding the obstacle limitation surfaces and regulated the construction of the man-made structures in and beyond the surfaces. Existing objects that extend above a obstacle limitation surfaces should as for as practicable be removed except when, in the opinion of the appropriate authority, an objects is shielded an existing immovable objects, or after aeronautical study it is determined that the object would not adversely affect the safety or significantly affect the regularity of operations of airplanes. However, Korea's aviation law does not specified the outer horizontal surface in the obstacle limitation surfaces, while ICAO and most member states do. The absence of the outer horizontal surface regulation has created legal disputes between regulating agencies and private parties. The case study in this paper found that a skyscraper planned beyond Korea's obstacle limitation surfaces does affect the flight safety and the efficient use of an airport. Therefore, in areas beyond the obstacle limitation surfaces. those objects which extend to a height of 150m or more above ground elevation should be regarded as obstacle, unless a special aeronautical study indicates that they do not constitute a hazard to airplanes. We proposed low alternative regulatory schemes for resolving the issues raised in this paper, and we recommended to adopt ICAO's standards and recommended practices.