Reliability Analysis for Fracture of Concrete Armour Units

콘크리트 피복재의 단면파괴에 대한 신뢰성 해석

  • Published : 2003.06.01

Abstract

A fracture or breakage of the concrete armor units in the primary cover layer of breakwaters is studied by using the reliability analysis which may be defined as the structural stability. The reliability function can be derived as a function of the angle of rotation that represents the rocking of armor units quantitatively. The relative influences of all of random variables related to the material and geometric properties on the fracture of armor units is analyzed in detail. In addition, the probability of failure for the fracture of individual armor unit can be evaluated as a function of the incident wave height. Finally, Bernoulli random process and the allowable fracture ratio may be introduced together in this paper, by which the probability of failure of a breakwater due to the fracture of armer units can be obtained straightforwardly. It is found that the probability of failure of a breakwater due to the fracture of armor units may be varied with the several allowable fracture ratios. Therefore, it should be necessary to consider the structural stability as well as the hydraulic stability for the design of breakwaters with multi-leg slender concrete armor units of large size under wave action in deep water.

방파제의 경사면에 거치된 콘크리트 피복재의 단면파괴에 대한 신뢰성 해석을 수행하였다. 신뢰함수는 피복재의 흔들림 또는 동요의 크기를 정량적으로 나타내는 회전각의 함수로 유도되었다. 방파제 단면에 거치된 피복재의 재질적 성질 및 기하학적 형상과 관련된 확률변수들의 단면파괴에 미치는 영향 정도가 자세히 해석되었다. 또한 파고의 함수로 피복재 개개의 단면파괴에 대한 파괴확률이 산정 되었다. 마지막으로 Bernoulli과정과 허용파손율의 개념을 동시에 고려하여 피복재의 단면파괴가 어떻게 방파제 제체의 파괴확률로 이어지는가가 해석되었다. 허용파손율 개념은 본 연구에서 도입된 것으로, 허용파손율을 어떻게 정의하느냐에 따라 피복재의 단면파괴에 의하여 유발되는 방파제 제체의 파괴확률이 다르게 거동되는 것을 확인할 수 있었다 따라서 상대적으로 수심이 깊은 곳에 중량이 큰 콘크리트 피복재를 사용하여 방파제를 설계할 때는 수리학적 안전성뿐만 아니라 구조적 안전성도 중요하게 고려되어야 한다.

Keywords

References

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