• Title/Summary/Keyword: Seismic Overturning Moment

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Experimental Study on the Seismic Response of High-Rise RC Bearing-Wall Structures with Irregularity (고층 RC 벽식 비정정 구조물의 지진거동에 관한 실험적 연구)

  • 이한선;고동우
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.321-328
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    • 2003
  • The objective of this study is to investigate the seismic response of high-rise RC bearing-wall structures with irregularity. For this purpose, three 1:12 scale 17-story reinforced concrete model structures were constructed according to the similitude law, in which the upper 15 stories have a bearing-wall system while the lower 2-story frames have three different layouts of the plan : The first one is a moment-resisting frame system, the second has a infilled shear wall with symmetric plan and the third has a infilled shear wall with eccentricity, Then, these models were subjected to a series of earthquake excitations. The test results show the followings: 1) the existence of shear wall reduced greatly shear deformation at the piloti frame, but has almost the negligible effect on the reduction of the overturning-moment angle, 2) the frame with shear wall resists most of overturning moment in severe earthquake, 3) the torsional behavior is almost independent of the translational, 4) the absorbed energy due to the overturning deformation has the largest portion in the total absorbed energy.

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Analytical solution of seismic stability against overturning for a rock slope with water-filled tension crack

  • Zhang, Yanjun;Nian, Tingkai;Zheng, Defeng;Zheng, Lu
    • Geomechanics and Engineering
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    • v.11 no.4
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    • pp.457-469
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    • 2016
  • Steep rock slope with water-filled tension crack will happen to overturn around the toe of the slope under seismic loading. This failure type is completely different from the common toppling failure occurring in anti-dipping layered rock mass slopes with steeply dipping discontinuities. This paper presents an analytical approach to determine the seismic factor of safety against overturning for an intact rock mass slope with water-filled tension crack considering horizontal and vertical seismic coefficients. This solution is a generalized explicit expression and is derived using the moment equilibrium approach. A numerical program based on discontinuous deformation analysis (DDA) is adopted to validate the analytical results. The parametric study is carried out to adequately investigate the effect of horizontal and vertical seismic coefficients on the overall stability against overturning for a saturated rock slope under two water pressure modes. The analytical results show that vertically upward seismic inertia force or/and second water pressure distribution mode will remarkably decrease the slope stability against overturning. Finally, several representative design charts of slopes also are presented for the practical application.

Seismic Design Guidelines for Welded Steel Oil Storge Tank (KS B 6225) (강제석유저장탱크(KS B 6225)의 내진설계기준 개선 안)

  • Park, Jong-Ryul;O, Taek-Yeol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.544-552
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    • 2002
  • Recommended seismic design guide for the flat bottom vortical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

Seismic Design Guidelines for Welded Steel Oil Storge Tank (KS B 6225) (강제 석유 저장 탱크(KS B 6225)의 내진 설계 기준 개선 안)

  • Park, Jong-Ryul;Oh, Taek- Yul
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.166-173
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    • 2001
  • Recommended seismic design guide for the flat bottom vertical-cylindrical oil storage tanks in KS B 6225 is presented. Under earthquake excitations, the hydrodynamic pressure exerted on the tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea, zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described.

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Seismic Design Program for Oil Storage Tank (액체저장탱크의 내진설계 프로그램 개발)

  • 박종률;오택열
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.551-555
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    • 1997
  • IJnder earthquake excitations, the hydrodynamic pressure exerted on the flat bottom vertical-cylindrical oil storage tank walls produces overturning moment which may cause either a failure of the anchors or a buckling of the tank shell near its base. The basis for establishing design loads due to hydrodynamic pressure is described including seismic zone risk map in Korea. zone coefficients and the essential facilities factor. This procedure for calculating applied compressive stress on the shell base subjecting to seismic load and for estimating the allowable buckling stress is described. And seismic design program for the tanks is presented.

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Seismic behavior of steel frames with replaceable reinforced concrete wall panels

  • Wu, Hanheng;Zhou, Tianhua;Liao, Fangfang;Lv, Jing
    • Steel and Composite Structures
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    • v.22 no.5
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    • pp.1055-1071
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    • 2016
  • The paper presents an innovative steel moment frame with the replaceable reinforced concrete wall panel (SRW) structural system, in which the replaceable concrete wall can play a role to increase the overall lateral stiffness of the frame system. Two full scale specimens composed of the steel frames and the replaceable reinforced concrete wall panels were tested under the cyclic horizontal load. The failure mode, load-displacement response, deformability, and the energy dissipation capacity of SRW specimens were investigated. Test results show that the two-stage failure mode is characterized by the sequential failure process of the replaceable RC wall panel and the steel moment frame. It can be found that the replaceable RC wall panels damage at the lateral drift ratio greater than 0.5%. After the replacement of a new RC wall panel, the new specimen maintained the similar capacity of resisting lateral load as the previous one. The decrease of the bearing capacity was presented between the two stages because of the connection failure on the top of the replaceable RC wall panel. With the increase of the lateral drift, the percentage of the lateral force and the overturning moment resisted by the wall panel decreased for the reason of the reduction of its lateral stiffness. After the failure of the wall panel, the steel moment frame shared almost all the lateral force and the overturning moment.

Structural member stiffness influence on vertical earthquake behaviour of mid-rise R/C frame buildings in Turkey

  • Selcuk Bas
    • Computers and Concrete
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    • v.33 no.6
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    • pp.689-706
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    • 2024
  • This study is aimed at identifying structural element stiffness influence on vertical earthquake response of mid-rise R/C frame buildings. To this aim, a mid-rise RC building structure is designed as per the new Turkish Seismic Code for Buildings-2018, and 3D FE model of the building is established. Based on the established FE model, a total number of six buildings are considered depending on certain percentage increase in beam, slab, and column. The time-history response analyses (THA) are performed separately for only horizontal (H) and horizontal +vertical (H+V) earthquake motions to make a comparison between the load cases. The analysis results are presented comparatively in terms of the monitoring parameters of the base overturning moment (Mo), the top-story lateral displacement (dL) and the top-story vertical displacement (dV). The obtained results reveal that the base overturning moment and the top-story vertical displacement are affected by vertical earthquake motion regardless of the increase in the dimension of beam, slab, and column. However, vertical earthquake motion is not effective on the top-story lateral displacement due to no change between H and H+V load. The dimensional increase in either slab or beam leads to a considerable increase in the base overturning moment and the top-story vertical displacement while causing decrease in the top-story lateral displacement. In addition, the dimensional increase in column has a positive effect on the decrease in the monitoring parameters of the base overturning moment (Mo), the top-story lateral displacement (dL) and the top-story vertical displacement (dV).

Experimental Evaluation on the Base Shear Force of a Bas Isolation System (면진구조물의 기초전단력에 대한 실험적 평가)

  • 김영중
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.04a
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    • pp.169-177
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    • 1999
  • The base shear force and the overturning moment are important factors for the earthquake design of a structure. These should be predicted exactly especially when the nonlinear seismic isolation bearings are used against earthquake motions. Generally these are derived by the acceleration responses of a structure with the he assumed masses. However these can be contaminated by the noise in the measured responses and the uncertainty of assumed masses. This paper presents the results of the derived base shear force and overturning moment compared with the measured results by multi-axis load cells. Also discussions are made on the cross-coupling effects of the multi-axis load cell.

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A Study on Hybrid Wall System on Connection Type of Coupling Beam (커플링 보의 접합방식에 따른 복합 벽체 시스템에 관한 연구)

  • Yun, Hyun-Do;Park, Wan-Shin;Han, Byung-Chan;Yun, Yeo-Jin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.4
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    • pp.201-208
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    • 2003
  • The Hybrid Wall System(HWS) building composed of center core reinforced concrete walls and exterior steel frame has open space around the center core walls. It is necessary to develop design methodologies for the HWS building that the coupled shear walls withstand the most of lateral load and expect the most energy dissipation at the coupling beams and at wall foots. Major factors considered in this paper are connection type of coupling beams and scale of story. The studies of the system are investigated in terms of shear force, overturning moment, maximum lateral displacement, story drift ratio, and dynamical characteristics under the action of vertical and lateral forces such as wind and seismic loads.

Configuration and Design of the Large Multi-Electromagnetic Shaking System (대형 멀티 전자기 가진 시스템의 구성 및 설계)

  • 우성현;김홍배;문상무;김영기;임종민
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.618-622
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    • 2004
  • The vibration test system of SITC(Satellite Integration and Test Center) at KARI(Korea Aerospace Research Institute) has been used successfully for the environmental tests of a majority of korean space programs, such as KOMPSAT, Koreasat KITSAT, STSAT and KSR program since 1996. To meet the recent needs of large size test facility available for the vibrational tests of the huge launch vehicles and tole-communication satellites which will be developed in the near future, KARI undertook to construct the large size multi-electromagnetic shaking system with 3 $\times$ 3m head expander system. The new system will consist of three electromagnetic shakers which has 160 kN thrust force individually, and be able te sustain up to 8 tons test load and 300 kNm overturing moment. And to avoid the tremendous cost and effort to furnish the seismic block with large size and weight, it will adopt a Lin-E-Air type configuration with which the seismic block is less severe than a Solid-Truninon type. In addition, to fulfill the strong requirement of high overturning moment the additional guidance system including a central bearing system on a central support and several pad bearings around the head expander body is now considered. This paper describes the configuration and the design parameters of the multi-shaking system which is under development by KARI's engineers.

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