Study of Response Characteristics and Strength Parameter Evaluation of Water Intake Tower Under Different Amplitude Modulation Modes

This study selected a simplified water intake tower model, simplifying the physical structure into a cantilever model, and MATLAB software (R2010b) was used to develop a rapid seismic response analysis program for the structure. Thirty near-fault pulse and non-pulse ground motions were selected as the input ground motions for this analysis. Peak ground velocity (PGV) was used as the intensity parameter for the ground motions. The acceleration, cross-sectional rotation, and lateral curvature of the simplified water intake tower model were calculated for ground motions modulated with different PGA amplitudes. The acceleration, maximum shear force, and cross-sectional rotation of the simplified water intake tower model were also calculated for ground motions modulated with improved effective peak acceleration (IEPA) and improved effective peak velocity (IEPV). The study showed that the seismic response of the simplified water intake tower model for near-fault ground motions modulated with different intensities of PGV amplitude modulation was closer to the unmodulated response order. PGV as an intensity parameter did not affect the acceleration response amplification factor of the water intake tower and hoist chamber. The AC coefficient indicated that PGV was less suitable for pulse-type earthquake amplitude modulation than PGA. Compared with PGA amplitude modulation, IEPA amplitude modulation is more suitable for pulse-type seismic motion, while IEPV amplitude modulation has less impact on pulse-type seismic motion.