• Title/Summary/Keyword: allowable displacement

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Performance Evaluation on Static Loading and Cyclic Loading for Structural Insulated Panels (구조용단열패널의 정적가력과 반복가력 성능 평가)

  • Nah, Hwan-Seon;Lee, Hyeon-Ju;Choi, Sung-Mo
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.4 no.1
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    • pp.33-39
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    • 2013
  • Structural insulated panels, structurally performed panels consisting of a plastic insulation bonded between two structural panel facings, are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. In Korea, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to identify fundamental performance of both monotonic load and quasi static cyclic load for SIPs in shear wall application. Static test results showed that maximum load was 44.3kN, allowable shear load was 6.1kN/m, shear stiffness was 1.23 M N/m, and ductility ratio was 3.6. Cyclic test was conducted by two kinds of specimens : single panel and double panels. Cyclic test results, which were equivalent to static test results, showed that maximum load was 45.42kN, allowable shear load was 6.3kN/m. Furthermore the accumulated energy dissipation capability for double panels was as 2.3 times as that for single panel. From performance of structural tests, it was recommended that the allowable shear load for panels was at least 6.1kN/m.

Tabu search based optimum design of geometrically non-linear steel space frames

  • Degertekin, S.O.;Hayalioglu, M.S.;Ulker, M.
    • Structural Engineering and Mechanics
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    • v.27 no.5
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    • pp.575-588
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    • 2007
  • In this paper, two algorithms are presented for the optimum design of geometrically nonlinear steel space frames using tabu search. The first algorithm utilizes the features of short-term memory (tabu list) facility and aspiration criteria and the other has long-term memory (back-tracking) facility in addition to the aforementioned features. The design algorithms obtain minimum weight frames by selecting suitable sections from a standard set of steel sections such as American Institute of Steel Construction (AISC) wide-flange (W) shapes. Stress constraints of AISC Allowable stress design (ASD) specification, maximum drift (lateral displacement) and interstorey drift constraints were imposed on the frames. The algorithms were applied to the optimum design of three space frame structures. The designs obtained using the two algorithms were compared to each other. The comparisons showed that the second algorithm resulted in lighter frames.

Optimization of Steel Jacket Subjected to Wave Forces (파랑하중을 받는 Steel Jacket의 최적화에 관한 연구)

  • 장승필;이원표;원종국
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.2 no.1
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    • pp.43-50
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    • 1990
  • This study is concerned with the optimization of steel jacket subjected to wave forces using the allowable stress design method. The optimization of member section is considered here. Objective function for the minmum cost design is obtained by considering the weight of steel jecket. Constraints are imposed to insure that structural displacement and strength are within allowable values. The nonliner otimization problems are solved by SUMT method including the modified Newton-Raphson method.

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An Analytical Study on the Relationship between Factor of Safety and Horizontal Displacement of Soil Nailed Walls (쏘일네일 보강벽체의 수평변위와 안전율과의 관계 분석연구)

  • Kim, Hongtaek;Lee, In
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.2
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    • pp.45-53
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    • 2011
  • Soil nailing method was often designed by the slope stability analysis based on limit equilibrium. However, in the case of shorten length of nails, although the calculated factor of safety is within the design factor of safety, the horizontal displacement of soil nailed walls occurred above the allowable limit. In this study, relationship between the load and factor of safety, and relationship between the load and displacement ratio based on the test results were analysed. From the analysed results, the relationship between factor of safety and displacement ratio was estimated. For the mobilized horizontal displacement of the walls within the serviceability limit corresponding to the displacement of less than 0.3% displacement ratio, the calculated factor of safety by limit equilibrium analysis had to satisfy above 1.35. Also, although the minimum factor of safety is estimated above 1.35, the maximum horizontal displacement is often mobilized above 0.3% of excavation height. Therefore, it is necessary to perform the numerical analysis of soil nailed walls in the case of low shear strength or high excavation.

A Study on Characteristics of Hybrid Damping Device Combining Rubber Core Pad and Hysteretic Steel Slit (고무코어패드와 강재이력감쇠장치를 결합한 복합감쇠장치의 이력특성에 관한 연구)

  • Park, Byung-Tae;Lee, Joon-Ho
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.1
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    • pp.45-52
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    • 2023
  • This study proposes an RCS composite damping device that can achieve seismic reinforcement of existing buildings by dissipating energy by inelastic deformation. A series of experiments assessing the performances of the rubber core pad, hysteretic steel slit damping device, and hybrid RCS damping device were conducted. The results showed that the ratios of the deviations to the mean values satisfied the domestic damping-device conformity condition for the load at maximum device displacement in each direction, at the maximum force and minimum force at zero displacement, as well as the hysteresis curve area. In addition, three analysis models based on load-displacement characteristics were proposed for application to seismic reinforcement design. In addition, the validity of the three proposed models was confirmed, as they simulated the experimental results well. Meanwhile, as the shear deformation of the rubber-core pad increased, the hysteretic behavior of super-elasticity greatly increased the horizontal force of the damping device. Therefore, limiting the allowable displacement during design is deemed to be necessary.

A Study on Horizontal Displacement Following Ability of Welded and Non-welded Building Hardware (용접형과 무용접형 하지철물의 수평변위 추종능력에 관한 연구)

  • Lee, Don-Woo;Kwak, Eui-Shin;Shon, Su-Deok;Lee, Seung-Jae
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.4
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    • pp.75-82
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    • 2016
  • Building hardware joints are welded in most cases, which have risks of fire and explosion. Besides, the secondary damage of the destruction of the welded parts can be caused by the horizontal displacement of the structure due to earthquake or wind load. This paper compared the horizontal displacement following abilities of welded building hardware and non-welded building hardware. To do this, We conducted actual formation shake table test, and checked on the horizontal displacement following ability of structure by comparing their responses to earthquake load. We made the 2m-high framework to examine the responses of the actually constructed building hardwares, and analyzed the displacement responses of the welded-typed, non-welded-typed, and cruciform bracket building hardwares. We conducted the test by increasing acceleration rate until displacement reached 40mm corresponding to allowable relative story displacement II. The result of the test showed that the building hardware using welding work made cracking and breakage on welded connections of welded building hardware, but non-welded building hardware with no use of welding work and cruciform bracket building hardware make no problem, and that non-welded building hardware is superior to that of the welded building hardware in the horizontal displacement following ability due to earthquake or wind load.

Seismic Response on Thin Shell as Structural Foundation (기초구조물로서 얇은 쉘 구조물의 지진응답)

  • Yee Hooi Min;Azizah Abdul Nassir;Kim Jae Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.24 no.2
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    • pp.31-41
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    • 2024
  • This study aims to investigate the seismic response of a large span thin shell structures and assess their displacement under seismic loads. The study employs finite element analysis to model a thin shell structure subjected to seismic excitation. The analysis includes eigenvalue analysis and time history analysis to evaluate the natural frequencies and displacement response of the structure under seismic loads. The findings show that the seismic response of the large span thin shell structure is highly dependent on the frequency content of the seismic excitation. The eigenvalue analysis reveals that the tenth mode of vibration of the structure corresponds to a large-span mode. The time history analysis further demonstrates, with 5% damping, that the displacement response of the structure at the critical node number 4920 increases with increasing seismic intensity, reaching a maximum displacement of 49.87mm at 3.615 seconds. Nevertheless, the maximum displacement is well below the allowable limit of the thin shell. The results of this study provide insight into the behaviour of complex large span thin shell structures as elevated foundations for buildings under seismic excitation, based on the displacement contours on different modes of eigenvalues. The findings suggest that the displacement response of the structure is significant for this new application of thin shell, and it is recommended to enhance the critical displacement area in the next design phase to align with the findings of this study to resist the seismic impact.

Bearing Capacity of Driven H-Piles in Embankment (성토지반에 타입된 H형강 말뚝의 지지거동)

  • 박영호;정경자;김성환;유성근;이재혁;박종면
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.173-182
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    • 2000
  • To find axial and lateral responses of impact-driven H piles in embankment(SM), the H piles are instrumented with electric strain gages, dynamic load test is performed during driving, and then the damage of strain gages is checked simultaneously. Axially and laterally static load tests are performed on the same piles after one to nine days as well. Then load-settlement behavior is measured. Furthermore, to find the set-up effect in H pile, No. 4, 16, 26, and R6 piles are restriked about 1, 2, and 14 days after driving. As results, ram height and pile capacity obtained from impact driving control method become 80cm and 210.3∼242.3ton, respectively. At 15 days after driving, allowable bearing capacity by CAPWAP analysis, which 2.5 of the factor of safety is applied for ultimate bearing capacity, increases 10.8%. Ultimate bearing capacity obtained from axially static load test is 306∼338ton. This capacity is 68.5∼75.7% at yield force of pile material and is 4∼4.5 times of design load. Allowable bearing capacity using 2 of the factor of safety is 153∼169ton. Initial stiffness response of the pile is 27.5ton/mm. As the lateral load increases, the horizontal load-settlement behaves linearly to which the lateral load reaches up to 17ton. This reason is filled with sand in the cavity formed between flange and web during pile driving. As the result of reading with electric strain gages, flange material of pile is yielded at 19ton in horizontal load. Thus allowable load of this pile material is 9.5ton when the factor of safety is 2.0. Allowable lateral displacement of this pile corresponding to this load is 23∼36mm in embankment.

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Numerical Analysis of Laterally Displacing Abutment in High Landfill Slope (고성토사면에 시공된 교대의 측방유동에 대한 수치해석적 연구)

  • Park, Min-Cheol;Jang, Seo-Yong;Shin, Baek-Chul;Han, Heui-Soo
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.2
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    • pp.27-39
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    • 2012
  • This research is to propose the reinforcing method and design code for the lateral behaviors of the abutment displacement induced from the rainfall infiltration on high landfill slope. First, to make the proper numerical analysis, in-situ soil (weathered granite soil) was taken, and the variance of strength parameters according to water content variance was examined by undrained direct shear test, furthermore, other soil parameters were calculated from the standard penetration test such as elastic modulus and Poisson's ratio etc,. Those parameters were used to calculate the lateral behavior of abutment by finite element method and the member force of pile in high landfill slope according to rainfall infiltration . From the results, the shoe displacement on abutment was calculated as 8.98cm, which is 3 times bigger than the allowable displacement, 3cm. To reinforce it, several reinforcing methods were selected and analyzed such as reinforced retaining wall, soil surcharge, pile reinforcing (5m enlargement, 3-line arrangement, 5m enlargement and 3-line arrangement). In case of 5m enlarged and 3-line arrangement piles, the lateral behavior of shoe showed lower value(2.26 cm) than allowable displacement.

Characteristics of Lateral Flow due to Embankments for Road Construction on Soft Grounds Using Vertical Drain Methods (연직배수공법이 적용된 연약지반 상에 도로성토로 인한 측방유동의 특성)

  • Hong, Won-Pyo;Kim, Jung-Hoon
    • Journal of the Korean Geotechnical Society
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    • v.28 no.9
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    • pp.5-15
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    • 2012
  • Field monitoring data for embankments in thirteen road construction sites at coastal area of the Korean Peninsula were analyzed to investigate the characteristics of lateral flow in soft grounds, to which vertical drain methods were applied. First of all, the effect of the embankment scale on the lateral flow was investigated. Thicker soft soils and lager relative embankment scale produced more horizontal displacements in soft grounds. Especially, if thick soft grounds were placed, the relative embankment scale, which was given by the ratio of thickness of soft ground to the bottom width of embankments, became larger and in turn large horizontal displacement was produced. And also higher filling velocity of embankments induced more horizontal displacements in soft grounds. The other major factors affecting the lateral flow in soft ground were the thickness and undrained shear strength of soft grounds, the soil modulus and the stability number. Maximum horizontal displacement was induced by less undrained shear strength and soil modulus of soft grounds. Also more stability numbers produced more maximum horizontal displacements. When the shear deformation does not develop, the stability number was less than 3.0 and the safety factor of bearing was more than 1.7. However, if the stability number was more than 5.14 and the safety factor of bearing was less than 1.0, the unstable shear failure developed in soft ground. 50mm can be recommended as a criterion of the allowable maximum horizontal displacement to prevent the shear deformation in soft ground, while 100mm can be recommended as a criterion of the allowable maximum horizontal displacement to prevent the shear failure in soft ground.