Seite - 1232 - in Book of Full Papers - Symposium Hydro Engineering

Interaction between water and solid areas is considered as frictionless and LAYZMER boundary condition is considered for the free end of the lake. Sliding of the dam heel and abutments is neglected because of being small (2). USBR code is also employed for calculation of the dead, seismic, uplift, hydrostatic and hydrodynamic loads. 3. RESULTS Five LSFs of drift failure mode for KARUN IV arch concrete dam under earthquakes loading have been extracted by RSM. The functions have been analyzed with six approaches and the ?̂? 𝑓 of dam is presented. RSM is adjusted in polynomial mode. The LSF then obtained by considering the failure drift and the performance of dam (i.e. 𝑔 (𝒙 =𝐸 𝑓 /𝐸 𝑑 )=0.0025−𝐷 𝑟 𝑖 𝑓 𝑡 ). Obtained results by six mentioned approaches are presented. 4. CONCLUSION It is concluded that CHI-CHI earthquake has the most impact on dam failure and the failure probability is much more than the other earthquakes, considering the foundation flexibility as a random variable. It is also concluded that Subset Simulation method has the best performance in terms of standard deviation of answers and it’s results are very close to MCS. Importance Sampling can be also employed for reliability analysis of dam because it is able to find the approximate (near to MCS) failure probability with a few number of function calls. REFERENCES [1] USBR, ”Guidelines for preliminary design of arch dams”, A water resources technical publication engineering monograph, No. 36, USA, 1977. [2] HUAIZHI S., JINYOU L., ZHIPING W., ZHAOQING F., Dynamic non- probabilistic reliability evaluation and service life prediction of arch dam considering time-varying effect. Applied mathematical modelling, VOL. 40, p.p. 6908-6923, 2016. [3] MAHAB GHODS (MGCE), Karun IV arch Concrete Dam General Layout and Abutment Stability, Consulting Engineers. [4] RASHKI M., MIRI M., MOGHADDAM M.A., “A new efficient simulation method to approximate the probability of failure and most probable point,” Structural Safety, Vol. 39, p.p. 22–29, 2012. [5] A. S. NOWAK AND K. R. COLLINS, Reliability of structures. CRC Press, 2012. 1232