【摘要】 坝身泄洪的拱坝振动位移均方差是反映坝体振动强烈程度的重要指标,由于开展拱坝原型振动测试的测点有限,难以全面准确反映拱坝坝体的整体振动响应场分布特性,仅利用有限测点的动位移均方差进行坝体振动安全评价显得不够全面和具体,因此通过有限测点的实测响应反演出整个坝体结构的动位移场具有重要意义。以二滩高拱坝为工程实例,对其开展了原型泄洪振动测试,通过布置于坝体上的有限测点的原型实测动位移响应,基于遗传算法和有限元模态分析对该拱坝原型整体动位移场进行了反演,并给出了拱坝原型动位移场反演的具体流程图;反演结果表明,仅利用坝体顶拱拱圈的7个动位移响应测点实测值反演出了整个拱坝在泄洪工况下的动位移场,且反演结果与实测结果较为吻合,该方法为高拱坝的泄洪振动安全的正确评估提供了新的技术手段。更多还原

【Abstract】 The mean square deviation of the dynamic displacement of an arch dam during the flood discharge period is an important indicator for evaluating the intensity of vibration. It is difficult to reflect the distribution characteristics of a whole vibration response field accurately if relying directly on the limited points measurement in dynamic test and also it is not comprehensive and concrete to evaluate the dam vibration safety only with the data measured at limited points. So it is of great significance to inverse the whole dynamic displacement field of the arch dam based on the dynamic response measurement at limited measuring points. Taking the Ertan high arch dam as an engineering example,the dam vibration test under flood discharge excitation was carried out. In accordance with the dynamic displacement responses at limited measuring points arranged on the prototype arch dam,the whole dam dynamic displacement field was inversed by using the genetic algorithm and finite element modal analysis. The specific flow chart of the inversion was provided. The inversion results show that the whole dam dynamic displacement field can be obtained through the dynamic displacement response measurement at only seven measuring points arranged on the top arch of the dam. Simultaneously,the inversion results and the measured values are in good agreement. The method provides a new technique for the reasonable safety assessment of high arch dam during the flood discharge period.更多还原