【摘要】 提出一种计算直立坝面上地震动水压力的高精度时域公式,与坝体有限元模型结合用于考虑坝-水动力相互作用,避免半无限库水区域的数值模拟。在频域内,基于库水区域分离变量解析解和坝-水交界面条件推导精确的坝面动水力-坝面绝对水平运动关系,之后利用作者已经提出的时间卷积局部化方法将该关系转化为含有辅助变量的高阶精度时域公式。该公式的时空离散形式与坝体有限元模型的耦合方程,可以采用显式时间积分方法求解。为了能够利用商用有限元平台分析非线性坝体-库水动力相互作用问题,在ABAQUS有限元软件中通过UEL用户单元子程序二次开发实现了提出的动水力公式,公式用户单元在有限元建模阶段与坝体有限元模型无缝结合,后续动力计算过程中无须重启动等任何特别处理。刚性坝面地震动水压力分析表明,提出公式的计算结果稳定,并与解析解较好吻合;之后将该公式应用于Koyna重力坝地震反应分析。更多还原

【Abstract】 A high-accuracy time-domain formulation for the seismic hydrodynamic pressure on the vertical up-stream face of dam is proposed,which couples with the dam finite element model to consider the dam-reservoir interaction.The numerical model of the semi-infinite reservoir is thus avoided.In frequency domain,the exact relationship between hydrodynamic force and total horizontal motion is obtained based on the analytical solution of reservoir and the dam-reservoir interface condition.This relationship is transformed into the high-accuracy time-domain formulation with auxiUary functions by using the temporal convolution localization method proposed by authors.This formulation,in spatially and temporally discrete form,can be incorporated into the dam model,leading to the dynamic equations of a dam-reservoir system,which is solved by an explicit algorithm developed by authors.It is implemented by an UEL module of ABAQUS so that the commercial code can be used to analyze a seismic nonlinear dam-reservoir interaction problem,and the UEL module can couple with the dam model in construction of the finite element model,avoiding any special treatment such as restart in solution process.Application of this new formulation to hydrodynamic pressure on a rigid dam demonstrates that the solution is stable and agrees very well with the analytical results.A seismic response analysis of Koyna gravity dam is also given.更多还原