• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.553-558
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• 2015

교량의 주탑, 초고층빌딩과 같이 세장비가 큰 대형구조물의 경우 풍하중에 취약한 특성을 지니고 있어서 바람에 의해 직각 방향으로 발산 진동하는 갤로핑(galloping) 현상이 발생하게 된다. 구조물의 진동을 억제하려는 방안으로 단면 형상에 변화를 주어 공기역학적 불안정성을 감소시키는 방법이 사용되고 있다. 본 논문에서는 Edison_CFD를 이용하여 모서리 절단부의 비율과 받음각에 따른 공기력 특성에 대한 전산해석을 수행하였다.

• Geotechnical Engineering
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• v.11 no.2
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• pp.29-36
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• 1995

Load testis are executed on model reticulated root piles (RRP) to figure out the optimum slanting angle in the piles installation. One set of model RRP consists of 8 slanting piles which are installed in circular patterns forming two concentric circles, each of which is made by 4 piles. Each pile which is a steel bar of 5m in diameter and 300mm in length is coated to become a pile of 6.5mm in diameter. The slanting angle of the model RRP varies from 0$^{\circ}$ to 20$^{\circ}$ Comparing ultimate bearing capacities of the model RRP of different installation angles, it is observed that the ultimate capacities of the RRP increase as the installation angle increases until 15$^{\circ}$, and the optimum slanting angle of the RRP is around 15$^{\circ}$ The ultimate bearing capacity of the 15$^{\circ}$-RRP is found to be 22% bigger than that of the vertical RRP and 120% bigger than that of the circular surface footing whose diameter is same with the circle formed by outer root piles'heads. However, it is noticed that when the slanting angle of the RRP is increased over 15$^{\circ}$, the ultimate capacity starts to be reduced. The ultimate capacity of 20$^{\circ}$-RRP is even smaller than that of the vertical RRP by as much as 5%. From the observation of the load settlement curve obtained during the RRP load tests, it is known that as the slanting angle gets bigger the load -settlement behavior becomes more ductile.