【摘要】 根据"5·12"汶川地震峰值加速度衰减关系,推求坝址基岩EW、NS、UD方向峰值加速度分别为0.52g、0.46g、0.43g,然后采用比例法将实测加速度记录(051MXT)换算得到紫坪铺大坝动力计算的输入加速度时程;在利用建设阶段变形监测资料反演堆石体静力模型参数得到大坝静应力的基础上,结合吉林台、猴子岩等工程室内试验资料类比得到了堆石体反映振动硬化特性动力模型的初步参数,并结合关门山、察汗乌苏等工程的现场原位试验资料和大坝实测地震加速度的频谱特性进行了调整复核;通过计算输入地震加速度的等效振动周数,利用实测资料对大坝堆石体的永久变形参数进行了反演分析。结论认为:振动硬化动力模型反映了大坝堆石体地震过程中的"震缩"现象,"5·12"汶川地震主震时间较长和坝址近震的铅直向加速度较大,是紫坪铺大坝震后永久变形较大的主要原因,Ⅱ、Ⅲ期混凝土面板的错台由于堆石体永久变形引起的次生破坏。现有土石坝动力分析理论和方法基本可以反映土石坝的抗震性能。更多还原

【Abstract】 Based on the"5·12"Wenchuan Earthquake peak acceleration attenuation relations,the peak acceleration of the decided dam bedrock ground on the EW,NS,UD directions were 0.52g,0.46g,and 0.43g,respectively,and the measured acceleration records(051MXT) were converted to the input acceleration time history of Zipingpu Dam by using the ratio method.Based on rockfill E-B model parameters inversion by the construction phase deformation monitoring data and Jilintai,Houziyan and other projects laboratory test data,the initial parameters of dynamic models with vibration hardening characteristics were gained,which were adjusted to theGuanmenshan,Chahanwusu-situ testing data and the dam measured spectral characteristics of the earthquake acceleration.By calculating effective vibration times to the input earthquake acceleration and using the measured data,the rockfill permanent deformation parameters were decided by the inversion analysis.It was concluded that the vibration hardening dynamic model reflects the rockfill material’shock shrinkage’phenomenon during an earthquake.The main reason of the larger Zipingpu dam permanent deformation during "5 ·12" Wenchuan earthquake are both the longer main shock time and the near earthquake.The shear failure of concrete slab between Ⅱ and Ⅲ stage is secondary damage caused by rockfill permanent deformation.Existing dynamic analysis theories and methods of embankment dam can basically reflect earth rock dam seismic characteristics.更多还原