基于EMD分离水压分量的重力坝变形参数反演分析

Back analysis of deformation parameters of gravity dam based on EMD separated water pressure component

通过材料参数反分析建立能准确模拟大坝结构行为的数值模型,是大坝安全监控的重要手段之一。根据监测数据的水压分量进行混凝土坝参数反分析是目前常用的方法。提出了一种利用经验模态分解(EMD)剔除监测数据的时效分量后再分离水压分量的方法,有助于提高水压分量分离的准确性;同时,结合响应面代理模型和遗传算法,提高了参数反分析效率。以YL重力坝为例,根据其坝顶顺河向位移和坝体应变的实测数据,对坝体和坝基的弹性模量进行了反演。结果表明,与设计参数相比,采用反演参数模拟的坝体位移水压分量与实测值更为吻合,能够更加准确地对该重力坝的工作性态进行分析和解释。

It is an important means for dam safety monitoring to establish a numerical model which can accurately simulate the behavior of dam structure through back analysis on material parameters.Back analysis on concrete dam parameters based on water pressure component in monitoring data is a common method at present.Empirical Mode Decomposition(EMD)is an intrinsic mode function that can eliminate the time effect component in monitoring data and separate water pressure component.It facilitates accurate water pressure component separation.At the same time,the response surface surrogate model and genetic algorithm are integrated into the analysis to improve the parameter back analysis efficiency.Taking a YL Gravity Dam as an example,the elastic moduli of the dam body and dam foundation were back analyzed based on the measured dam crest displacement along river and the strain of dam body.The results show that the water pressure component of displacement simulated based on inversion parameters is more consistent with the measured value than that simulated based on design parameters,thus the working behavior of the gravity dam can be analyzed and interpreted more accurately.