| 초록 |
The formulas for computing natural frequencies and the modes of varied section dam on layered foundation with exponential function shear modulu are derived according to shear beam theory. Furthermore, the seismic responses of the dam and the layered foundation are calculated using mode-superposition scheme. Dynamic responses of the dams and the layered foundations to earthquake are studied by the theory of random vibration, in which two cases Of power spectral intensity function for earthquake acceleration inputing at base rock are considered: the white noise spectrum and the filter white noise spectrum. The numerical calculation results show that: (1) In the case that the power spectral density of the earthquake acceleration inputing at base rock is the white noise spectrum, the maximum expected responses of the layered foundation and the dam are different from the case of the filter white noise spectrum. (2) In stationary importing and exporting, the maximum expected responses of the dam and the foundation are as same as that in the case of stationary importing and no stationary exporting. (3) In both case of the earthquake acceleration inputing at base rock and the stationary random response process, the random responses of the foundation and the dam are over-estimated . |
