混凝土坝振动参数区间逆分析

Interval inversion analysis for vibration parameters of concrete dam

考虑模态观测数据的不确定性 ,引入不确定问题求解的区间分析思想 ,建立了利用先验约束条件的混凝土重力坝动态参数的区间反演模型 ;并采用约束变尺度方法求解该反演模型获得待求参数的区间范围 .以某大坝空库情形为例 ,在振动观测数据不完全的条件下 ,对该方法进行了考察 .结果表明 ,在只有一阶圆频率和几个固定点处有一阶振型观测数据的情况下 ,可以可靠地识别出坝体混凝土和基础岩石的动弹性模量所在区间范围 ;该方法具有一般性 。

Considering the uncertain property of measured mode data and the prior constrained information of variables, an interval inversion analysis model was built to identify the vibration parameters of the concrete dam and the rock basement by using the interval analysis method. The constrained variable metric algorithm was used to solve the present model to obtain the intervals of the parameters. The present process was inspected by using the incomplete measured data of the concrete gravity dam under the condition of the empty reservoir. Numerical results show that the intervals of the elastic modulus of the dam concrete and the rock basement could be reliably identified by using the first order vibration mode values at several fixed points in the dam. The present process in this paper is of a general method and can be used to identify the vibration parameters of structures.