碾压混凝土坝等效黏弹性参数反演

Inversion of the Equivalent Viscoelastic Parameters of the Roller Compacted Concrete Dam

根据碾压混凝土坝的成层结构特性,将层面影响概化到整个坝体中,将碾压混凝土坝视为横观各向同性体,建立了碾压混凝土坝等效黏弹性模型。根据位移实测资料,采用偏最小二乘法建立位移统计模型,分离水压分量和时效分量,建立反演碾压混凝土坝双向异性黏弹性参数的目标函数,并利用混沌遗传算法对黏弹性参数进行反演。工程实例中,将反演得到的黏弹性参数作为已知值,计算测点在相应时间段变形的水压和时效分量之和,并与分离出的实测值进行对比,结果表明:计算值与实测值比较接近,说明反演方法是正确、可行的。

According to the layer feature of roller compacted concrete dam （ RCCD）, this paper generalized the layer influence to the entire dam, and took roller compacted concrete dam as transverse isotropy, then built the equivalent viscoelastic model. According to the measured data, the dam displacement statistical model was established to separate the water pressure component and the aging component using the partial least squares regression method. And the objective function was established to inverse the hiaxial anisotropic viscoelastic parameters of roller compacted concrete dam utilizing chaos genetic algorithm. Through an engineering example, the inversed viscoelastic parameters were set as known values; the sum of the water pressure component and the aging component was calculated and was compared with the measured value. The results show that the calcu- lated value approximates to the objective value and prove that this inversion method is feasible.