• Title/Summary/Keyword: 동적 수평하중

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Earth Pressure Acting on Rigid Retaining Wall due to the Dynamic Load (동하중에 의한 강성벽체에 작용하는 토압)

  • 박종덕;전용백
    • Journal of the Korean Geotechnical Society
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    • v.16 no.5
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    • pp.157-168
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    • 2000
  • 토류구조물의 안정문제로는 장단기적으로 정적인 경우와 동적인 경우, 그리고 지반의 동적 거동특성, 흙의 강도저하 등을 미리 파악하여 기술적인 대처를 할 필요가 있을 것이다. 본 연구에서는 실내 모형 실험을 통하여 구조물의 배면에 토성이 다른 일반모래, 표준모래, 점성토를 뒷채움하여 다짐없이 강사만 하고, 룰러다짐, 진동다짐을 하여 토피의 수평 진동거리를 길게, 짧게 그리고 중간으로 하여 강성벽체에 작요?는 수평토압에 대한 정적, 동적 특성을 규명하는 것이다. 모형 실험장치로는 실험대, 토조, 토압측정장치, 진동하중 발생장치, 진동측정장치, 강사기, 롤러 등을 설치하여 거리에 따른 병진운동으로 가속도와 수평토압, 수평토압계수, 전체토압, 토압의 작용점, 지진토압증분 증을 구하여, 실험결과와 기존 이론결과, 그리고 유한요소 해석결과와 비교 고찰하였다.

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Characteristics of the Human Strength Acting on the Lightweight Wall of Buildings (인간이 경량벽체에 가하는 수평하중의 크기에 관한 연구)

  • Choi, Soo-Kyung;Roh, Yong-Woon;Kim, Sang-Heon;Lee, Young-Do
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.5
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    • pp.473-481
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    • 2015
  • The purpose of this research is to comprehend experimentally the characteristics of human strength for using as the basic data of impact resistance test method of lightweight wall. Human motions exerting static load are classified to 4 types. Pushes with two hands or shoulder are defined as the instantaneously forcing motions with hands or shoulder put on the force plate. Leanings back or one-hand against the wall are defined as motions of taking a rest in their respective comfortable posture. Human motions exerting dynamic load are classified to 3 types. Selecting 3 levels of motion strength (weak, middle, strong), 3 levels of force plate stiffness (A: 20kN/cm, B: 4.7kN/cm, C: 2.2kN/cm), and 30 male subjects, load was measured when they applied strength to the force plate. Results of this research are as follows: (1) The maximum load ratio (Pmax/W) of static load for each motion was 1.17-1.25 in two hands pushing, 0.95-0.99 in shoulder pushing, 0.16-0.18 in back leaning, and 0.12-0.15 in one hand leaning. (2) Human dynamic load and object collision were different in the load characteristics. (3) The maximum load ratio of dynamic load for each motion was 10.07 in heel kick, 4.46 in shoulder hitting, and 5.58 in fist blow.

Mechanical Characterization of Lead-Rubber Bearing by Horizontal Shear Tests (수평 전단시험에 의한 납 삽입 적층고무베어링의 기계적 특성 평가)

  • 전영선;최인길;유문식
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.6
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    • pp.1-10
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    • 2001
  • In this study, the horizontal loading tests of 10ton and 200ton capacity of LRB(lead-rubber bearing) were performed for the evaluation of the dynamic properties of the LRB. It is noted from the test results that dynamic properties of the LRB are dependent on the loading frequency, vertical load and shear strain. A Slender bearing subjected to large deformation will tend to develop plastic hinges in the end regions of the lead plug which will cause the failure of the lead plug. It is recommended that the appropriate mechanical properties of LRB considering the level of structural response and input ground motion should be used in the design of base isolated structures.

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The effect on fatigue life for dynamic behavior of external fuel tank horizontal fin (외부 연료탱크 수평 핀 동적거동이 피로수명에 미치는 영향)

  • Kim, Geun-Won;Shin, Ki-Su
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.3
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    • pp.209-214
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    • 2012
  • Recently, there were significantly increased cracks failure for external fuel tank horizontal fin of F-5 aircraft. In this paper, the dynamic behavior of horizontal fin was to quantitate by using Finite Element Method. To achieve this goal, the fatigue analysis for time and frequeucy domain has been performed by using the dynamic load spectrum of speed brake. In conclusion, it was proved that fatigue life of the horizontal fin was reduced by the influence of dynamic behavior.

The Effect of Dynamic Behavior on Changing Pile Cap Size of Pile Group in Sandy Soil (사질토 지반에서 말뚝 캡 크기가 무리말뚝의 동적거동에 미치는 영향)

  • Lee, Hyunkun;Ahn, Kwangkuk;Kang, Hongsig
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.8
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    • pp.5-12
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    • 2019
  • A pile group, that consists of several piles connected by a pile cap, is used as the superstructure. The pile supports vertical and horizontal load to design the pile group, but the effect of bearing capacity of the pile cap has not considered. Various researches have been conducted to reflect the effect of bearing capacity of the pile cap in order to reduce the amount of piles in the range of the stability under the vertical load of the superstructure. However, the effect of bearing capacity under the horizontal seismic load has not been studied adequately. Therefore, a shaking table test was carried out with different-sized pile caps that support the superstructure in this study. This test was to verify the influence of the size of the pile cap in the group pile under the horizontal load. The result shows that the size of the pile cap affects to the dynamic behavior of the superstructure and the pile group. Also, the bigger size of the pile group makes the larger constraint effect of ground, and it results that both the ground and the pile moves as a whole.

Behavior of Horizontally Curved I-Girder Bridges under Seismic Loading (지진하중하에서의 수평곡선I형교의 거동특성)

  • Yoon, Ki Yong;Sung, Ik Hyun;Choi, Jin Yu;Kang, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.14 no.6
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    • pp.793-802
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    • 2002
  • This study presented a finite element formulation for the dynamic analysis of horizontally curved I-girder bridges. The stiffness and mass matrices of the curved and the straight beam elements are formulated. Each node of both elements has seven degrees of freedom, including the warping degree of freedom. The curved beam element is derived from Kang and Yoo's theory of thin-walled curved beams. The computer program EQCVB has been developed to perform dynamic analyses of various horizontally curved I-girder bridges. The Gupta method is used to solve the eigenvalue problem efficiently, while the Wilson-${\theta}$ method is used for the seismic analysis. The efficiency of EQCVB is demonstrated by comparing solution time with ABAQUS. Using EQCVB, the study is applied to investigate the dynamic behavior of horizontally curved I-girder bridges under seismic loading.

Behaviour Characteristics of Single Batter Pile under Dynamic Lateral Loads (동적 수평하중에 의한 단일 경사말뚝의 거동특성)

  • Kim, Jiseong;Noh, Jeongseob;Kang, Gi-Chun
    • Journal of the Korean Geotechnical Society
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    • v.33 no.9
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    • pp.49-60
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    • 2017
  • The purpose of this study is to investigate the behavior of a single batter pile with repeated lateral loading through model tests. Repeated loads were applied in one direction and two directions, and lateral resistance and bending moment were analyzed by varying the relative density of the ground. As a result, lateral resistance and maximum bending moment were increased in the order of Out batter, Plumb, and In batter when one-way and two-way dynamic lateral loads were applied. The depth at the maximum bending moment was more deeper with the loading. The moments at bottom layer were decreased in the order of Out batter, Plumb, and In batter but upper moments were increased with the same order. Also, various bottom and upper moments were small when the two-way dynamic lateral load was applied compared to one-way lateral load.

Experimental Study on the Characteristics of Steel Hysteretic Dampers with E-Shape Elements (E-Shape 강재이력댐퍼의 거동 분석)

  • 김인배;강형택;이민구;서주원
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.457-464
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    • 2003
  • 최근 교량의 건설에 있어서 내진설계가 주요문제로 부각되면서, 구조물의 진동응답을 제어 하는 갖가지 형태의 진동제어 기법이 적용되고 있다. LRB(Lead Rebbe. Bearing), LUD(Lock Up Device)등 다양한 지진격리장치가 설계에 적용되고 있으며 특히, 설계변경 .내진보수보강과 같이 제약 조건이 있는 상황에서 유용한 면진방법으로 사용되고 있다. 이러한 지진격리장치는 기본적인 설계특성인 수평강성, 감쇠성능에 대한 검증을 필요로 한다. 특히, 지진과 같은 동적하중에 대하여 하중속도, 수직력, 변형률 등에 대한 의존성과 내구성의 검토가 필요하며 유사장치에 대하여 검증실험기준의 정립이 진행 중에 있다. 강재이력댐퍼인 E-Shape 댐퍼는 지진격리장치로서 교각의 고정단에 교좌장치로 설치되어 상시에는 탄성영역 내에서 거동하는 고정단의 역할을 하다가, 지진발생시에는 E-Shape형태의 강재댐퍼가 소성변형을 통한 이력거동으로 에너지 소산기능을 가진 교좌장치이다. 최근 LRB에 대하여는 다양한 특성실험이 수행되고 있으나 상대적으로 강재이력댐퍼에 대하여는 이러한 검증실험이 수반되지 않고 사용되고 있다. 본 실험연구에서는 E-Shape 강재이력댐퍼에 대하여 연직하중, 수평변형률, 수평속도에 패한 동적특성을 평가함으로서 강재이력댐퍼를 이용한 지진격리설계의 타당성과 면진성능을 평가해 보았다.

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Research on Dynamic Behavior of Double-Layer Barrelvault Arch Systems Subjected to Earthquake Loadings (지진하중에 대한 복층 배럴볼트 시스템의 동적거동에 대한 연구)

  • Shin, Ji-Wook;Lee, Ki-Hak;Jung, Chan-Woo;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.9 no.1
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    • pp.87-94
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    • 2009
  • This paper presents dynamic behavior of double-layer barrelvault systems subjected to earthquake loadings. In order to investigate different seismic behaviors according to Time History Analysis (THA), six open angles were employed and different fundamental frequencies corresponding to each open angle were considered. A total of 24 double-layer structures were developed by using Midas Gen., which is a computer analysis program and then THA with three different earthquakes with 5% damping ratio was performed. This study investigated the characteristics of the dynamic response for X-, Y- and Z- directions, both subjected to the horizontal earthquake (H) and applied to the vertical earthquake (V) with respect to the each variable, which assumed to be important aspects for spatial structure. In order to examine the dynamic characteristics, the ratio of acceleration in specific nodes of barrelvaults was evaluated at the time with maximum response. The main purpose of this study is to obtain equations of the equivalent earthquake loading with respect to the barrelvault systems.

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A Review of the Types and Characteristics of Horizontal Load Affecting the Structural Safety of the Lightweight Dry Walls (건식 경량벽체의 구조안전성에 영향을 미치는 수평하중의 종류 및 특성 고찰)

  • Song, Jung-Hyeon;Roh, Yong-Woon;Kin, Ki-Jun;Choi, Soo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.43-45
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    • 2013
  • The purpose of this study is to obtain basic data for making performance criteria about the structural safety of lightweight dry wall later by examining types and characteristics of horizontal load acting on the wall. The subjects applying horizontal load to the wall are human and objects. The types of horizontal load are classified as static load and dynamic load depending on the difference of acting time. The magnitude of horizontal load "0.25kN/㎡" defined by KBC 2009 has no significant meaning since it is the unsubstantial nominal load. The result of examining types and characteristics of horizontal load is as follows. (1) Static load by human needs to have more systematic investigation including differences in wall hardness and human weight. (2) Dynamic load by human needs to raise the significance of study result by increasing the number of subjects. (3) Dynamic load by objects needs to accumulate the load specific data for various load subjects considering real situations.

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