• Title/Summary/Keyword: 풍하중기준

Search Result 56, Processing Time 0.018 seconds

Verification on the Application of Monitoring for Frame Structures Using the VRS-RTK Method through the Free Vibration Test (자유 진동 실험을 통한 VRS-RTK 기법을 이용한 골조 구조물의 모니터링 적용성 검토)

  • Choi, Se-Woon;Park, Hyo-Seon;Kim, Bub-Ryur;Lee, Hong-Min;Kim, You-Sok
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.18 no.1
    • /
    • pp.174-182
    • /
    • 2014
  • To monitor the wind-induced responses of buildings, conventional real-time kinematic (RTK) methods based on two global positioning system (GPS) receivers (e.g., a reference and a rover) are widely applied. However, these methods can encounter problems such as difficulty in securing and maintaining a space for a reference station. With the recently developed virtual reference station (VRS)-RTK approach, the position of a structure can be measured using only a rover receiver. In this study, to evaluate the applicability of VRS-RTK methods in monitoring the lateral structural responses of frame structures, we performed free vibration tests on a one-story frame model (the first natural frequency of 1 Hz) and a three-story frame model (the first natural frequency of 0.85 Hz). To assess the reliability of the displacement and acceleration responses measured by the GPS, we performed a concurrent measurement using laser displacement sensors and an accelerometer. The accelerometer results were consistent with the GPS measurements in terms of the time history and frequency content. Furthermore, to derive an appropriate sampling rate for the continuous monitoring of buildings, the errors in the displacement responses were evaluated at different GPS sampling rates (5, 10, 20 Hz). The results indicate that as the sampling rate increased, the errors in the displacement responses decreased. In addition, in the three-story model, all modal components (first, second, and third modes) could be recorded at a sampling rate of 20 Hz.

Estimation of Topographic Effects over 3-Dimensional Hills with Different Slopes through Wind Tunnel Tests (경사가 다른 3차원 산악지형에서의 풍동실험을 통한 풍속할증평가)

  • Cho, Kang-Pyo;Cheong, Myung-Chae;Cho, Gi-Sung
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.20 no.3
    • /
    • pp.379-386
    • /
    • 2007
  • In this paper, topographic factors over 3-dimensional hills were estimated through wind tunnel tests. Topographic models having five different slopes of $5.71^{\circ}, \;11.31^{\circ},\;16.70^{\circ},\;21.80^{\circ}$, and $26.57^{\circ}$ which were based on Korean Building Code(KBC(2005), were made for wind tunnel tests. From the result of wind tunnel tests, topographic factors over 3-dimensional hills were obtained at various locations, and the ranges of topographic effects were decided. The ranges of topographic effects was whole area of the hills in the horizontal ranges and heights of 3.5 times of the hills in the vortical ranges. Topographic effects was large at the top of hills, and wind velocity was increased 57% over hill of $5.71^{\circ}$, 75% over hill of $11.31^{\circ}$, 79% over hill of $16.70^{\circ}$, 81% over hill of $21.80^{\circ}$, and 61% over hill of $26.57^{\circ}$. Wind velocity was bigger over surface of across-wind direction of hills than one over surface of wind direction of hills, and wind velocity was increased $10{\sim}30%$ at locations of across-wind direction.

Behaviors of Pile Croup Installed Near Inclined Ground (경사지반에 인접하여 설치된 무리말뚝의 거동연구)

  • Chae, Kwang-Seok;Ugai, Keizo;Yoon, Gil-Lim
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.3
    • /
    • pp.53-64
    • /
    • 2003
  • Many transmission towers, high-rise buildings and bridges are constructed near steep slopes and are supported by large-diameter piles. These structures may be subjected to large lateral loads, such as violent winds and earthquakes. Widely used types of foundations for these structures are pier foundations, which have large-diameters with high stiffness. The behavior of a pier foundation subjected to lateral loads is similar to that of a short rigid pile because both elements seem to fail by rotation developing passive resistance on opposite faces above and below the rotation point, unlike the behavior of a long flexible pile. This paper describes the results of several numerical studies performed with a three-dimensional finite element method (FEM) of model tests of a laterally loaded short pile located near slopes, respectively. In this paper, the results of model tests of single piles and pile groups subjected to lateral loading, in homogeneous sand with 30$^{\circ}$ slopes and horizontal ground were analyzed by the 3-D FE analyses. The pile was assumed to be linearly elastic. The sand was assumed to have non-associative characteristics, following the MC-DP model. The failure criterion is governed by the Mohr-Coulomb equation and the plastic potential is given by the Drucker-Prager equation. The main purpose of this paper is the validation of the 3-D elasto-plastic FEM by comparisons with the experimental data.

An Empirical Study of Soundproof wall with Reduced Wind Load (풍하중 저감형 방음판의 실증 연구)

  • Choi, Jin-Gyu;Lee, Chan-Young
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.12
    • /
    • pp.272-278
    • /
    • 2018
  • Traffic volume has been greatly increasing due to urban development and the improvement of living standards, and many complaints are being raised due to the increasing road noise. As a countermeasure against these problems, highly soundproof walls are installed on the sides of roads. However, the ability to bear wind loads is a major design requirement for soundproof walls, which contributes to the exponential increases in construction costs and restricts the height of the walls. The aim of this study is to improve the performance of soundproof walls and to dramatically reduce wind loads while maintaining excellent price competitiveness. Based on Helmholz's resonator theory, a new concept is proposed for a ventilation-type soundproofing plate that can pass through a fluid like air and reduce noise. A full-scale metal soundproofing plate was produced to satisfy the quality standards of highways by conducting a sound-pressure transmission-loss test, wind tunnel test, and material quality test. To verify the reliability, the wall was manufactured and installed, and the sound insulation effect was examined by measuring the noise over time. In the future, ventilated soundproof walls on roads could create a pleasant living environment due to the high noise-insulation effect.

Structural Performance Evaluation of a Multi-span Greenhouse with Venlo-type Roof According to Bracing Installation (가새 설치에 따른 벤로형 지붕 연동온실의 구조성능 평가)

  • Shin, Hyun Ho;Choi, Man Kwon;Cho, Myeong Whan;Kim, Jin Hyun;Seo, Tae Cheol;Lee, Choung Kuen;Kim, Seung Yu
    • Journal of Bio-Environment Control
    • /
    • v.31 no.4
    • /
    • pp.438-443
    • /
    • 2022
  • In this study, the lateral loading test was performed to analyze structural performance of multi-span plastic greenhouse through full-scale experiment and numerical analysis. In order to analyze the lateral stiffness and stress, we installed 9 displacement sensors and 19 strain gauge sensors on the specimen, respectively, and load of l mm per minute was applied until the specimen failure. In the comparison between the full-scale experiment and the structural analysis results of a multi-span greenhouse with venlo-type roof according to bracing installation, there was a large difference in the lateral stiffness of the structure. By installing a brace system, the lateral stiffness measured near the side elevation of the specimen increased by up 44%. As the bracing joint used in the field did not secure sufficient rigidity, the external force could not be transmitted to the entire structure properly. Therefore, it is necessary to establish a bracing construction method and design standards in order for a greenhouse to which bracing applied to have sufficient performance.

Effect of Wind Load on Pile Foundation Stability in Solar Power Facilities on Slopes (풍하중이 경사지 태양광 발전시설의 기초 안정성에 미치는 영향 분석)

  • Woo, Jong-Won;Yu, Jeong-Yeon;Song, Ki-Il
    • Journal of the Korean Geotechnical Society
    • /
    • v.39 no.12
    • /
    • pp.47-60
    • /
    • 2023
  • At present, in South Korea, there is a growing concern regarding solar power facilities installed on slopes because they are prone to damage caused by natural disasters, such as heavy rainfall and typhoons. Each year, these solar power facilities experience soil erosion due to heavy rainfall and foundation damage or detachment caused by strong wind loads. Despite these challenges, the interaction between the ground and structures is not adequately considered. Current analyses primarily focus on the structural stability under external loads; the overall facility site's stability-excluding the solar structures-in relation to its surrounding slopes is neglected. Therefore, in this study, we use finite-difference method analysis to simulate the behavior of the foundation and piles to assess changes in lateral displacement and bending stress in piles, as well as the safety factor of sloped terrains, in response to various influencing factors, such as pile diameter, spacing between piles, pile-embedding depth, wind loads, and dry and wet conditions. The analysis results indicate that pile spacing and wind loads significantly influence lateral displacement and bending stress in piles, whereas pile-embedding depth strongly influences the safety factor of sloped terrains. Moreover, we found that under certain conditions, the design criteria in domestic standards may not be met.