乐昌峡大坝地震响应分析

Seismic Rsponse Analysis of Lechangxia Dam

乐昌峡大坝位于广东省韶关市乐昌市境内,建造时按照Ⅴ度区进行抗震设计,随着2016年第五代地震动参数区划图的实施,该区设防烈度提高为Ⅵ度,大坝在Ⅵ度地震影响下是否安全需要进行分析。利用图纸资料建立了大坝的三维有限元模型,计算分析了多水位下特征坝段的频率和大坝的地震响应,结果表明:溢流坝段的频率小于两岸挡水坝段。地震作用下,大坝位移最大值出现在坝顶处,应力最大处出现在闸墩、牛腿及坝踵处,但均处于安全范围,证明大坝抗震性能良好;库水水位会显著影响大坝的频率及地震响应,在抗震设计时,应引起注意。

The Lechangxia Dam is located in Lechang City, Shaoguan City, Guangdong Province., and was constructed according to the seismic design of the Ⅴ degree zone. With the implementation of the fifth-generation ground motion parameter zoning map in 2016, the fortification intensity of this area has been increased to Ⅵ degree and whether the dam is safe under the influence of Ⅵ degree earthquake needs to be analyzed. By using the drawing data,the article establishes a three-dimensional finite element model of the dam,calculates and analyzes the frequency of the characteristic dam section under multiple water levels and the seismic response of the dam. The results show that the frequency of the overflow dam section is less than that of the retaining dam sections on both banks. Under earthquake,the maximum displacement of the dam appears at the top of the dam,and the maximum stress appears at the piers,corbels and heels of the dam,but they are all in a safe range,which proves that the dam has good seismic performance. The reservoir water level will significantly affect the frequency and seismic response of the dam,which should be paid attention to during seismic design.