摘要
由于混凝土坝变形监测系统有时是在大坝蓄水以后才开始安装及观测,从而丢失了此前由蓄水及坝体温度变化引起的变形量,即变形初值,给安全监测分析带来了困难。为了解决该问题,本文提出了一种变形初值反演方法,据此校准观测数据,还原坝体变形的真实面貌。其实施过程主要分4个步骤:(1)确定大坝变形的基准值,文中对此也进行了探讨并给出了一种确定方法;(2)基于实测资料,运用统计分析、有限元及数值优化方法,对坝体弹性模量、导温系数、线膨胀系数等热力学参数进行反演分析;(3)模拟施工和蓄水过程,开展坝体温度场和变形场的有限元计算;(4)以实测变形与有限元计算值最佳逼近为目标,反演大坝变形初值并实现观测数据校准。对白山重力拱坝的实例计算表明,该方法是正确有效的,可以在类似工程中推广应用。
In some circumstances,the deformation monitoring system of a concrete dam was not installed or not put to use until water impounding.Therefore,the deformations due to water load and temperature change before impounding were lost,thus brought difficulties to data analysis of safety monitoring.In order to overcome such shortcoming,a method to find out these initial deformations is put forward and will be used to calibrate the observed data and expose the truth of dam deformations.The implement of this method can be divided into four steps.（1） to set up a reference value for the deformations,and a reasonable way to do so is also proposed in this paper.（2） to carry out inverse analysis for thermal and mechanical parameters including elastic modulus,thermal diffusivity and thermal expansion coefficient of the dam according to observed data with statistical analysis,FEM and numerical optimization.（3） to compute the temperature and displacement variation histories with aid of FEM by simulating the processes of dam construction and impounding.（4） to calculate the initial deformations based on best approaching between observed data and FEM outcomes and use them to calibrate the original observed data.The application of this method to deformation calibration for Baishan arch dam shows that this method is valid and can be applied to similar engineering projects.
出处
《水利学报》
EI
CSCD
北大核心
2012年第10期1223-1229,共7页
Journal of Hydraulic Engineering
基金
河海大学水文水资源与水利工程科学国家重点实验室专项基金(20095860120)
中央高校基本科研业务费专项资金(B1020083)
关键词
混凝土坝
变形初值
反演
校准
concrete dam
initial deformation
inverse analysis
calibration
