• Title/Summary/Keyword: Construction Sequence Analysis

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Applications of Construction Sequence Analyses to Prototype Models of Twisted Tall Buildings (비틀림 초고층 프로토타입 모델에 대한 시공단계해석의 적용)

  • Choe, Mi-Mi;Kim, Jae-Yo;Eom, Tae-Sung;Jang, Dong-Woon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.89-97
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    • 2013
  • With regard to complex-shaped tall buildings whose plans and constructions have been gradually on the increase, this study was aimed to analyze their structural behaviors during construction by applications of construction sequences analyses to prototype models. For twisted tall buildings, total 18 models of with three conditions of a lateral load-resisting system, a twisting angle, and a construction method were selected. A diagrid system and a braced tube system were applied as a lateral load-resisting system. For each lateral load-resisting system, three types of plan with $0^{\circ}$, $1^{\circ}$, and $2^{\circ}$ twisting angles and three construction methods with construction sequences of exterior tube and interior frame were assumed. The structural performances of tall buildings under constructions were analyzed with results of lateral displacements from construction sequence analyses. Also, construction performances of the construction period and the maximum lift weight were compared.

Finite Element Analysis of Underground Electrical Power Cable Structures Considering the Effects of Construction Sequence (시공단계별 영향을 고려한 터널 전력구의 유한요소해석)

  • Kim, Sun-Hoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.2
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    • pp.147-155
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    • 2013
  • In this paper structural analysis of underground electrical power cable structures which is excavated below the surface of the earth in the downtown area is carried out considering the effect of construction sequence. There are many various life-line facilities below the surface of the earth in the downtown area. MPDAP was used for finite element analysis of underground electrical power cable structures. Three typical sections are simulated by finite element models. Unbalanced equilibrium problems may be occurred when conventional finite element procedures were used for simulation of tunnel excavation. Therefore equilibrium perturbation concept was applied to solve these problems. The effects of time-dependent deformations in advancing tunnel excavation are considered in the stages of construction sequences as using the load distribution factor. It is shown that values of maximum displacement of both soil and rock surrounding underground electrical power cable structures obtained by our numerical studies are less than allowable values.

Applications of Practical Analysis Scheme for Evaluating Effects of Over-Loads during Construction on Deflections of Flat Plate System (플랫 플레이트 시스템의 처짐에 대한 시공 중 과하중의 영향 평가를 위한 실용해석 기법의 적용)

  • Kim, Jae-Yo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.1
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    • pp.25-34
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    • 2009
  • RC flat plate, which has no large flexural stiffness by boundary beams, may be governed by serviceability as well as strength condition. A construction sequence and its impact on distributions of construction loads among slabs tied by shores are decisive factors on immediate and long term performances of flat plate. The over-loading and tensile cracking in early-aged slabs significantly increase the deflection of flat plate system. In this study, for slab deflections, the practical analysis scheme using a linear analysis program is formulated with considering construction sequence and concrete cracking effects. The concept of the effective moment of inertia in calculating deflections of one-way bending member, that is presented in structural design codes, is extended to the finite element analysis of the two-way slab system of flat plates. Effects of over-loads during construction on deflections of flat plate system are analyzed by applying the proposed practical analysis scheme into the critical construction load conditions calculated from the simplified method.

Isolation of a cDNA Encoding a Chloroplast Triosephosphate Isomerase from Strawberry

  • Kim, In-Jung;Lee, Byung-Hyun;Jinki Jo;Chung, Won-Il
    • Journal of Plant Biotechnology
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    • v.2 no.3
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    • pp.115-121
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    • 2000
  • A cDNA clone encoding chloroplast triosephosphate isomerase (TPI-cp) was isolated from strawberry fruit cDNA library. Sequence analyses indicated that the cDNA contains an open reading frame of 314 amino acids (33.5 kDa) composed of a transit peptide (59 amino acids) in amino terminal region and mature protein (255 amino acids). The existence of transit peptide in the deduced amino acid sequence implies that it encodes a chloroplast isoform. The protein sequence is more similar to other plant chloroplast isoforms than cytosolic isoforms. RNA blot analysis indicated that its expression is ubiquitous in examined five tissues, flowers, leaves, petioles, roots and fruits, and shows differential pattern according to fruit ripening. Genomic DNA blot analysis showed that TPI-cp is encoded by multiple genes in strawberry. Through sequence comparison and phylogenetic tree construction, TPI-cp is distinctively grouped into dicot and chloroplast isoforms.

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Evaluation and Adjustment of Lateral Displacement of Complex-shaped RC Tall Buildings Considering the Displacement by Tilt Angle of Each Floor (층경사각에 의한 횡변위를 고려한 비정형 고층건물의 횡변위 평가/보정)

  • Kim, Yungon
    • Journal of the Korea Concrete Institute
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    • v.27 no.5
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    • pp.551-558
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    • 2015
  • Lateral displacement in the most complex-shaped tall buildings is caused by eccentric gravity loads which are induced by the difference in location between a center of mass and a center of stiffness. The lateral displacements obtained from analysis, using conventional procedures, are prone to overestimate the actual values because much of realignment efforts made during construction phase are ignored. In construction sequence analysis, the self-leveling of slab and the verticality of columns/walls could be considered at each construction stage. Moreover, the displacement compensation can be achieved by manual process such as re-centering - locating to global coordinates through surveying. Because the lateral displacement increases with the building height, it is necessary to set up adjustment plan through construction stage analysis in advance in order to result in displacements less than the allowable limits. Because analytical solution includes lots of assumptions, the pre-adjusting displacement should be reasonably controlled with considerations for the uncertainty due to these assumptions.

Binary Sequence Family for Chaotic Compressed Sensing

  • Lu, Cunbo;Chen, Wengu;Xu, Haibo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.9
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    • pp.4645-4664
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    • 2019
  • It is significant to construct deterministic measurement matrices with easy hardware implementation, good sensing performance and good cryptographic property for practical compressed sensing (CS) applications. In this paper, a deterministic construction method of bipolar chaotic measurement matrices is presented based on binary sequence family (BSF) and Chebyshev chaotic sequence. The column vectors of these matrices are the sequences of BSF, where 1 is substituted with -1 and 0 is with 1. The proposed matrices, which exploit the pseudo-randomness of Chebyshev sequence, are sensitive to the initial state. The performance of proposed matrices is analyzed from the perspective of coherence. Theoretical analysis and simulation experiments show that the proposed matrices have limited influence on the recovery accuracy in different initial states and they outperform their Gaussian and Bernoulli counterparts in recovery accuracy. The proposed matrices can make the hardware implement easy by means of linear feedback shift register (LFSR) structures and numeric converter, which is conducive to practical CS.

Simplified sequential construction analysis of buildings with the new proposed method

  • Afshari, Mohammad Jalilzadeh;Kheyroddin, Ali;Gholhaki, Majid
    • Structural Engineering and Mechanics
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    • v.63 no.1
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    • pp.77-88
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    • 2017
  • Correction Factor Method (CFM) is one of the earliest methods for simulating the actual behavior of structure according to construction sequences and practical implementation steps of the construction process which corrects the results of the conventional analysis just by the application of correction factors. The most important advantages of CFM are the simplicity and time-efficiency of the computations in estimating the final modified forces of the beams. However, considerable inaccuracy in evaluating the internal forces of the other structural members obtained by the moment equilibrium equation in the connection joints is the biggest disadvantage of the method. This paper proposes a novel method to eliminate the aforementioned defect of CFM by using the column shortening correction factors of the CFM to modify the axial stiffness of columns. In this method, the effects of construction sequences are considered by performing a single step analysis which is more time-efficient when compared to the staged analysis especially in tall buildings with higher number of elements. In order to validate the proposed method, three structures with different properties are chosen and their behaviors are investigated by application of all four methods of: conventional one-step analysis, sequential construction analysis (SCA), CFM, and currently proposed method.

Realistic Analysis Method for Continuously Block-Placed Mass Concrete Structures Considering Block Size and Sequence of Concrete Placement (매스 콘크리트 구조물의 연속 분할타설시 타설블록의 크기 및 타설순서를 고려한 합리적인 수화열 해석)

  • 오병환;전세진;유성원
    • Journal of the Korea Concrete Institute
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    • v.11 no.3
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    • pp.59-67
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    • 1999
  • The mass concrete structures are generally constructed in an incremental manner by deviding the whole structures by a series of many blocks. The temperature and stress distributions of any specific block are continuously affected by the blocks placed before and after the specific block. For an accurate analysis of mass concrete structures, the sequence of all the blocks must be accordingly considered including the change of material properties with time for those blocks considered. The purpose of this study is to propose a realistic analysis method which can take into account not only the influence of the sequence, time interval and size of concrete block placement on the temperatures and stresses, but also the change of material properties with time. It is seen from this study that the conventional simplified analysis, which neglects material property changes of some blocks with time and does not consider the effect of adjacent blocks in the analysis, may yield large discrepancies in the temperature and stress distributions of mass concrete structures. This study gives a method to choose the minimum number of blocks required to obtain reasonably accurate results in analysis. The study provides a realistic method which can determine the appropriate size and time interval of block placement, and can be efficiently used in the design and construction of mass concrete structures.