区间分析在桥墩抗震性能评估中的应用

Application of interval analysis to evaluating aseismatic properties of bridge piers

介绍了现存桥梁抗震性能评估过程 ,用区间建模评估过程中的不确定性量及区间运算求地震力和最大弯矩的值域 ,评估过程应用测试的环境振动 ,评估计算分两种情况 :一是只能估计现存桥梁的固有频率 ,应用迭代过程可求得等效长度的区间向量 ;二是固有频率和振型都可以使用 ,直接可计算桥墩的等效长度。区间分析给出桥墩最大弯矩的值域 ,对抗震评估更接近于实际情况 ,并给出一个具体实例 。

The procedure of evaluating aseismatic properties of the existing bridge is presented in this paper. The uncertainty parameters and intervals arithmetic are used to calculate the range value of the earthquake force and maximum bending moment. Using the measurement data of ambient vibration, the nature frequencies and modal shapes are estimated,and employed to compute the equivalent interval length of a bridge piers. If the nature frequencies are only available, a iterative process is developed for calculating the equivalent length. An example is studied,which shows that it is better to use interval analysis than conventional arithmetic.