考虑参数—激励复合随机的渡槽结构非线性地震响应与抗震可靠性分析

地震灾害对渡槽结构的破坏受多种因素的影响和制约，混凝土力学参数的随机性和地震激励的随机性为两种较为重要的影响因素，会对渡槽结构的破坏模式产生显著影响。进行混凝土力学参数和地震激励两种随机性耦合作用下的渡槽结构随机动力响应分析，以某大型渡槽结构为例，提出考虑参数—激励复合随机的渡槽结构抗震可靠性分析方法。基于概率密度演化理论，该方法阐明了渡槽结构在复合随机作用下可靠性分析的基本原理和应用途径。与单一地震随机作用的比较研究发现，复合随机作用下渡槽结构的位移响应明显加剧，且位移响应产生的残余变形和位移的变异性较大；随着阈值的减小，渡槽结构在复合随机作用下的可靠度与单一随机地震作用下的可靠度之间的差距呈不断增大趋势，且渡槽结构在两种工况下的可靠度均不断减小。

Nonlinear seismic response and reliability analysis of aqueducts subjected to coupled randomness from structural parameters and excitations

The damage of aqueduct structures caused by earthquake disaster is influenced and restricted by various factors. The randomness in concrete mechanical properties and seismic excitations are two of the significant factors that may alter the failure modes of aqueduct structures. To this end, this paper carried out systematically the random dynamic response analysis of aqueducts subjected to the above two coupled randomness condition. Further, the anti-seismic reliability analysis method for aqueducts considering the coupled randomness from both structural parameters and excitations is developed taking a large aqueduct structure as an example. The basic research principles and application approaches of the developed framework were illustrated in detail based on the probability density evolution theory. The results show that the displacement response of the aqueduct structure under the coupled randomness condition intensifies obviously, and the residual deformation and displacement variability of the displacement response are larger than that caused by the single randomness earthquake condition. With the decrease of threshold value, the gap between the reliability of aqueduct structure under coupled randomness condition and that under single randomness earthquake condition is increasing, and the reliability of aqueduct structure under the above two conditions is decreasing continuously.