基于有限元法的高拱坝分区变形模量反演分析

Parameter Inversion of Regional Deformation Modulus for High Arch Dam Using FEM

针对高拱坝位移响应模型复杂以及常规有限元反演方法计算量大的难题,提出了一种新的高拱坝分区变形模量快速近似反演方法.首先依据实际材料分区及几何特性,将坝体及坝基有限元模型分成若干区域;依据实际数值分布范围预设若干组线性无关的变形模量组合,并结合全过程或选取某时间区段的实际库水位变化过程,进行有限元正分析,得到各种组合下监测点的位移响应序列;以这些序列作为基序列,取代传统回归模型中的水压因子分量,并通过最优化拟合得到各因子回归系数;利用位移分量和分区弹模间的力学关系,进一步计算得到各分区综合变形模量的反演值.通过鱼简河工程实例对该方法进行了介绍和验证,结果显示回归水压分量与水位相关关系良好,回归系数合理,分区变形模量反演结果与设计值较为接近.

Concerning the complexity of displacement model and the time-costing problem of conventional FEM simulation for high arch dam,a novel and efficient approach is proposed for the parameter inversion of the zoning deformation moduli.Firstly the FE model including dam body and rock basement are divided into several zones according to the material distribution and geometric features;several linearly independent groups of deformation moduli are pre-selected within the possible range.Based on the monitored reservoir water level variation during the whole life or a certain time period,an associate displacement series can be obtained for each group via the finite element analysis;in replacement of the conventional water pressure component,here these displacement series are used to construct the regression model for the monitored displacement;and the regression coefficients are then calculated using optimization approach.According to their mechanical relationships with the displacement,the zoning elastic moduli can thus be calculated.The Yujianhe Arch Dam is taken as a demonstration and verification for the proposed method;and the simulated results show that the obtained water component has a good relationship with the water level;the regression coefficients are reasonable;and the calculated zoning deformation moduli are close to the designed values.