케이슨 방파제의 사용년수 동안의 기대활동량은 방파제의 안정성 평가 기준으로서 한계점이 있다. 기대활동량은 사용년수 동안의 모의 활동량의 평균으로 계산되기 때문에 실제 활동량은 평균을 초과할 가능성이 있다. 이를 극복하기 위해 허용활동량에 대한 초과확률을 산정하여 안정성을 평가하였다. 초과확률을 산정하기 위해 Latin Hypercube sampling과 Crude Monte Carlo simulation을 사용하였다. 또한 확률변수의 분포함수로 정규 분포가 가지는 단점을 해결하기 위해 이중절단정규분포를 사용하였다. 정규분포를 사용한 경우의 모든 한계상태에서 옥계항, 화순항, 동해 NI의 보강 전 단면은 불안정한 것으로 평가되었다. 한편, 이중절단정규분포를 적용한 경우에서 보수가능 한계상태의 화순항과 모든 한계상태의 동해 NI의 보강 전 단면만 불안정한 것으로 해석되었다. 결론적으로 안정성 평가 기준으로 기대활동량이 가지는 단점을 발견하였고 허용활동량에 대한 초과확률을 이용하여 국내 케이슨 방파제의 활동에 대한 안정성을 합리적으로 평가하였다.
케이슨 방파제의 사용년수 동안의 기대활동량은 방파제의 안정성 평가 기준으로서 한계점이 있다. 기대활동량은 사용년수 동안의 모의 활동량의 평균으로 계산되기 때문에 실제 활동량은 평균을 초과할 가능성이 있다. 이를 극복하기 위해 허용활동량에 대한 초과확률을 산정하여 안정성을 평가하였다. 초과확률을 산정하기 위해 Latin Hypercube sampling과 Crude Monte Carlo simulation을 사용하였다. 또한 확률변수의 분포함수로 정규 분포가 가지는 단점을 해결하기 위해 이중절단정규분포를 사용하였다. 정규분포를 사용한 경우의 모든 한계상태에서 옥계항, 화순항, 동해 NI의 보강 전 단면은 불안정한 것으로 평가되었다. 한편, 이중절단정규분포를 적용한 경우에서 보수가능 한계상태의 화순항과 모든 한계상태의 동해 NI의 보강 전 단면만 불안정한 것으로 해석되었다. 결론적으로 안정성 평가 기준으로 기대활동량이 가지는 단점을 발견하였고 허용활동량에 대한 초과확률을 이용하여 국내 케이슨 방파제의 활동에 대한 안정성을 합리적으로 평가하였다.
The expected sliding distance for the lifetime of a caisson breakwater has a limitation to be used as the stability criterion of the breakwater. Since the expected sliding distance is calculated as the mean of simulated sliding distances for the lifetime, there is possibility for the actual sliding ...
The expected sliding distance for the lifetime of a caisson breakwater has a limitation to be used as the stability criterion of the breakwater. Since the expected sliding distance is calculated as the mean of simulated sliding distances for the lifetime, there is possibility for the actual sliding distance to exceed the expected sliding distance. To overcome this problem, the exceedance probability of the allowable sliding distance is used to assess the stability of sliding. Latin Hypercube sampling and Crude Monte Carlo simulation were used to calculate the exceedance probability. The doubly-truncated normal distribution was considered to complement the physical disadvantage of the normal distribution as the random variable distribution. In the case of using the normal distribution, the cross-sections of Okgye, Hwasun, and Donghae NI before reinforcement were found to be unstable in all the limit states. On the other hand, when applying the doubly-truncated normal distribution, the cross-sections of Hwasun and Donghae NI before reinforcement were evaluated to be unstable in the repairable limit state and all the limit states, respectively. Finally, the shortcoming of the expected sliding distance as the stability criterion was investigated, and we reasonably assessed the stability of sliding of caissons by using the exceedance probability of allowable sliding distance for the caisson breakwaters in Korea.
The expected sliding distance for the lifetime of a caisson breakwater has a limitation to be used as the stability criterion of the breakwater. Since the expected sliding distance is calculated as the mean of simulated sliding distances for the lifetime, there is possibility for the actual sliding distance to exceed the expected sliding distance. To overcome this problem, the exceedance probability of the allowable sliding distance is used to assess the stability of sliding. Latin Hypercube sampling and Crude Monte Carlo simulation were used to calculate the exceedance probability. The doubly-truncated normal distribution was considered to complement the physical disadvantage of the normal distribution as the random variable distribution. In the case of using the normal distribution, the cross-sections of Okgye, Hwasun, and Donghae NI before reinforcement were found to be unstable in all the limit states. On the other hand, when applying the doubly-truncated normal distribution, the cross-sections of Hwasun and Donghae NI before reinforcement were evaluated to be unstable in the repairable limit state and all the limit states, respectively. Finally, the shortcoming of the expected sliding distance as the stability criterion was investigated, and we reasonably assessed the stability of sliding of caissons by using the exceedance probability of allowable sliding distance for the caisson breakwaters in Korea.
Burcharth, H.F. (1992). Uncertainty related to environmental data and estimated extreme events, Final Report of PIANC Working Group 12, Group B, June 1992
European Committee for Standardisation (1991). Eurocode 1 for Actions on Structures, European Committee for Standardisation
European Committee for Standardisation (1992). Eurocode 2 for Design of Concrete Structures, European Committee for Standardisation
Goda, Y.(1974). A new method of wave pressure calculation for the design of composite breakwater, Proc. 14th International Conference on Coastal Engineering, ASCE, Copenhagen, 1702-1720
Goda, Y. (2001). Performance-based design of caisson breakwaters with new approach to extreme wave statistics. Coastal Eng. J., 43, 289-316
Ikesue, S. (1999). Study on reliability design method of composite breakwaters using the expected sliding distance, Master Thesis, Kyoto University (in Japanese)
JPHA (2007). Japan Port and Harbor Association, Technical Standards for Port and Harbor Facilities in Japan (in Japanese)
Kim, S.-W. and Suh, K.-D. (2006) Application of reliability design methods to Donghae harbor breakwater, Coastal Engrg. J. 48(1), 31-57
Kim, T.M. and T. Takayama (2003). Computational improvement for expected sliding distance of a caisson-type breakwater by introduction of a doubly-truncated normal distribution. Coastal Eng. J., 45, 387-419
Oumeraci H., Kortenhaus A., Allsop W., de Groot M., Crouch R., Vrijling H., Voortman H. (2001). Probabilistic design tools for vertical breakwaters, Sweta & Zeitlinger B.V., Lisse
Park, S.K. and Miller, K.W. (1988). Communications of the ACM, 31, 1192-1201
Shimosako, K. and Takahashi, S. (2000). Application of deformation- based reliability design for coatal structures. Proc. Int. Conf. Coastal Struct., A.A. Balkema, Spain, 363-371
Takayama, T. and Ikeda, N. (1992) Estimation of sliding failure probability of present breakwaters for probabilistic design, Report of the Port and Harbour Research Institute, vol.31, No.5
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