基于实测应变反演大坝混凝土实际徐变度

Inversion of actual creep degree of dam concrete based on the measured strain

探讨了基于实测应变的大坝混凝土实际徐变度的反演方法.首先基于无应力计测值统计模型反演了混凝土热膨胀系数,并获得了降噪后的自生体积变形表达式;接着建立了施工期应变计测值统计模型,获得降噪后实测应变曲线;最后基于实测应变和计算应变,建立了反演徐变度表达式8参数的非线性规划约束极值问题模型,给出了徐变度表达式8参数的反演算法.结合建设中的西南某混凝土坝工程,验证了建议算法的适用性.分析结果表明,当加荷龄期较小时,反演徐变度较室内徐变值小;当加荷龄期较大时,反演徐变度在初期时小于室内徐变值,后期则大于室内徐变值.

Inversion of the actual creep degree of dam concrete based on the measured strain is discussed in the paper. The thermal expansion coefficient of the concrete is first inversed based on the statistical model with no stress measured, and the formula of the volume deformation is got after the noise reduction. Then we set up the strain gauge during the measurement of values of the statistical models, and get the strain curve after the noise reduction. Finally, based on the measured strain and calculated strain, the model for the inversion of creep degree with 8 parameters is established, and the inversion algorithm of the creep degree with 8 parameters is given. Combined with the construction of the concrete dam project located in the southwest region, the applicability of the algorithm in this paper is verified. Analysis shows that when the loading age is short, inversion creep degree is less than the indoor creep; when the loading age is long, the inversion creep degree in early time is less than indoor creep value, and the later inversion creep degree is more than indoor creep value.