考虑沉箱相互作用的直立式核电护岸地震响应分析

Seismic response analysis of upright revetment considering caisson interaction

以某核电站海域工程直立护岸为背景,通过运用接触单元对直立式沉箱在地震作用时的相互作用进行模拟,结合PL-Finn大变形模型,对比研究沉箱护岸在考虑沉箱间相互作用与不考虑相互作用情况下的地震响应,从沉箱间的接触挤压力、加速度时程、位移时程、结构变形、超孔压比、液化区域等方面定量评价护岸结构并总结地震响应规律。数值模拟结果表明:沉箱间的接触挤压作用将会加剧地震的作用效果,对加速度、变形以及砂土液化都会产生影响;且地震作用引发地基液化变形,沉箱易出现向海侧倾斜;砂土层超孔压比较大的区域主要集中在置换砂以及回填砂附近;所得到的结论可为以后类似项目提供参考。

Taking a vertical revetment of one Nuclear plant as background. Combined with the PL-Finn large deformation model, using contact unit of FLAC3 D finite analysis software. Compare the earthquake response of caisson revetment with caisson interaction and without caisson interaction. The revetment is evaluated from the contact force, the acceleration time course, the displacement time course, the structural deformation, the excess pore pressure ratio and the liquefaction area. The numerical simulation results shows the contact squeezing effect between the caissons will exacerbate the effect of the earthquake, which will affect the acceleration, deformation and liquefaction of the sand. The seismic action often causes the liquefaction deformation of the foundation, and the caisson will rotate and tilted to the sea side when strong earthquake encountered. Sand layer with large excess pore pressure ratio is mainly encountered in the replacement of sand area. The conclusion obtained in this paper can provide reference for similar projects in the future.