• Title/Summary/Keyword: parapet

Search Result 31, Processing Time 0.025 seconds

Shaking Table Test of Full Scale Parapet Models for the Evaluation of Intensities of Historical Earthquakes (성첩 모델의 진동대 실험과 역사지진의 세기 평가)

  • 김재관
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • 2001.04a
    • /
    • pp.461-467
    • /
    • 2001
  • Shaking table tests were performed with full scale models of stone parapet on the ancient rampart. The objectives of these tests are to study the seismic behavior of the parapet and to obtain quantitative estimation of the intensities of historical earthquakes. Two test models were made based on the structure of the parapet remnant of a mountain fortress in Bukhan-San located in Seoul. Two types of infilling material are considered. The responses to models were tested subjected to three kinds of input motion.

  • PDF

Stability Evaluation of Rear-Parapet Caisson Breakwaters under Regular Waves by Numerical Simulation (수치해석을 통한 규칙파를 받는 후부 패러핏 케이슨 방파제의 안정성 평가)

  • Lee, Byeong Wook;Park, Woo-Sun;Ahn, Sukjin
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.32 no.2
    • /
    • pp.95-105
    • /
    • 2020
  • In this study, using the CADMAS-SURF model, the characteristics of the wave pressures and the wave forces were analyzed according to the installation position of the parapet on top of the caisson, and the stability evaluation was carried out using estimated wave forces for the design wave condition. Numerical results show that adopting the rear-parapet reduces the front maximum wave pressures and wave forces, and the maximum wave pressure acting on the rear-parapet increases slightly compared to the front parapet, but the wave force acting on the rear-parapet has little effect on the stability of the breakwater due to the phase difference with the wave force acting on the front of the breakwater. In addition, impulsive wave pressures did not occur, as Yamamoto et al. (2013) pointed out the problem of the rear-parapet breakwater. As a result of the stability against sliding and overturning, it was estimated that the target safety factor of 1.2 could be secured by the self-weight of 13% less than the case of the front parapet. At this time, the maximum ground pressure was also reduced by 30%, and the applicability of the rear-parapet structure to the actual site was evaluated as high.

Effect of parapets to pressure distribution on flat top of a finite cylinder

  • Ozmen, Y.
    • Wind and Structures
    • /
    • v.17 no.5
    • /
    • pp.465-477
    • /
    • 2013
  • In this paper, the effects of parapets on the mean and fluctuating wind pressures which are acting on a flat top of a finite cylinder vertically placed on a flat plate have experimentally been investigated. The aspect ratio (AR) of cylinder is 1 and the Reynolds number (Re) based on cylinder diameter and free stream velocity is 150000. The pressure distributions on the flat top and the side wall of the finite cylinder immersed in a simulated atmospheric boundary layer have been obtained for different parapet heights. The large magnitudes of mean and minimum suction pressures occurring near the leading edge were measured for the cases with and without parapet. They shift to the further downstream on the circular top with increasing parapet height. It is seen that the parapets reduce the local high suction on the top up to 24%.

Effects of the Facade of the Buildings on the Sound Characteristics in an Apartment Complex (공동주택 입면 변화에 따른 단지 내 소음특성)

  • Kim, Yong-Hee;Lee, Pyoung-Jik;Jeon, Jin-Yong;Lee, Byung-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.11a
    • /
    • pp.367-370
    • /
    • 2005
  • This paper investigated the sound characteristics in an apartment complex. The field measurement was conducted in order to examine the acoustical characteristics of the apartment complex in situ. As a result, it shows that there are around 3 sec. reverberation time and the additional sound reinforcements at the area of high height due to the surrounded buildings. Thus, 1:50 Scale model measurement and Raynoise computer simulation were carried out with insertion of the parapet and the canopy on the balcony. In case of a single building, the parapet was effective to reduce noise level at low floor levels, and the canopy was effective to reduce noise level at high floor levels. But it also shows that both the parapet and the canopy were not effective to reduce noise level at middle floor levels. In case of an apartment complex, the canopy was less effective to reduce noise level at each floor in comparison with case of the single building.

  • PDF

Experimental Study for Downfall Pressure on the Floor behind Rubble-Mound Structure by Wave Overtopping: Non-Breaking Condition (월파에 의한 경사식구조물 배후면에 작용하는 낙하파압에 대한 실험적 연구: 비쇄파조건)

  • Lee, Jong-In;Moon, Gang Il;Kim, Young Il
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.34 no.2
    • /
    • pp.27-36
    • /
    • 2022
  • The large uprush could be occurred when the waves hit the coastal structure and this uprush by wave could make the overtopping. The downfall of the wave overtopping water over the structure brought about the vertical impact loads. The vertical impact loads should be evaluated in order to design the pavement behind the crown wall however these loads were still unclear. In this study, the hydraulic model tests for the downfall impact loads by wave overtopping were performed and the various conditions were applied to the tests. The effect of the incident wave condition, the freeboard, the armour crest height and the height of the parapet were investigated. The test results showed that the parapet on the crown wall could reduce the wave overtopping however the inclusion of parapet could lead to the increased downfall wave pressures behind the crown wall. The empirical formulae were proposed for evaluating the maximum downfall pressures behind the crown wall of rubble mound structure.

Development of a Dynamic Deformable Rubber Membrane Parapet to Cope with the Long Term Sea Level Rise and the Abnormal Waves (장기해수면 상승 및 이상파랑에 대비한 동적 가변형 고무막체 파라펫 개발)

  • Kim, Sun-Sin;Chun, In-Sik;Lee, Young-Gun;Ko, Jang-Hee;Hong, Seung-Ik
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.23 no.1
    • /
    • pp.34-42
    • /
    • 2011
  • It's been reported that the global warming effect has invoked the ever increasing typhoon intensity and long-term sea level rise which jointly cause severe wave overtopping over breakwaters or shore dykes. A simple measure to cope with this undesirable change may be just to increase the crest height of the dykes and breakwaters. This is surely effective to prevent wave overtopping, but it also decreases the seaward visibility of coastal waterfront. In this paper, a dynamic deformable rubber membrane parapet which not only reduces wave overtopping in storm period but also secures seascapes in normal days is presented. Several optimal configurations of the parapet are proposed. Through numerical analyses using a nonlinear finite element model and hydraulic experiments, the air controlled expansion and contraction of the parapets, their behavior against wave overtopping and structural stability are investigated.

Evaluation on the Photovoltaic Module Arrangement Planning Considering Shading Conditions in Apartment Buildings (음영조건을 고려한 공동주택 옥상 태양광모듈의 배치계획 평가 연구)

  • Lee, Keo-Re;Lee, Yoon-Sun;Lim, Jae-Han
    • Journal of the Architectural Institute of Korea Structure & Construction
    • /
    • v.35 no.5
    • /
    • pp.169-179
    • /
    • 2019
  • During the initial design stage of apartment complex, the photovoltaic(PV) system has been considered as an alternative of renewable energy system and planned to install at the rooftop floor level in general. The electric power generation characteristics can be influenced by the block layout, building orientation and roof top structure because of azimuth angle, tilt angle, and partial shading. This study aims to investigate power generation characteristics of photovoltaic system in apartment buildings by considering the partial shading conditions due to the block layout, building orientation and roof-top structures. For the photovoltaic module arrangement planning in rooftop floor level, shading areas were firstly analyzed due to the adjacent building structure. And the annual and seasonal power generation of PV system were analyzed through the PVsyst simulation results. The results show that shading period at the roof top surface can be increased due to the parapet and water tank. Initial design power capacity can be decreased by considering the daily insolation period and distance between PV modules through the shading simulation. As the number of PV modules decreases, the annual power generation can be decreased. However annual power generation per unit area of PV modules can be increased and performance ratio can be increased above 80%. Also the power generation of PV system can be critically affected by building orientation and the performance ratio can be drastically decreased in east-oriented buildings due to the shading problems caused by adjacent structures at roof top level such as parapet and water tank.