大坝设计地震的规定美国垦务局规定了作用在大坝结构上的三种地震荷载及相应的结构反应。这三种地震称做运行依据地震(OBE)、设计依据地震(DBE)和最大可信地震(MCE)。三种地震的确定准则和结构物的允许反应,规定如下:1.运行依据地震运行依据地震规定为,在结构经济寿命期间可发生若干次的地震。在奥本坝区,这种地震的重复时间间隔为25年一次。其震级由震级-频度曲线确定。该曲 Provisions for Dam Design Earthquakes The US Bureau of Reclamation provides for the three seismic loads acting on the dam structure and the corresponding structural responses. These three earthquakes are termed OBE and are based on DBE and MCE. The criteria for determining the three earthquakes and the allowable reactions of the structure are defined as follows: 1. Operational basis The seismic operation is based on the seismic regulation that several earthquakes may occur during the structural economic life. In the Oban dam area, the interval of such earthquakes is 25 years. Its magnitude is determined by the magnitude-frequency curve. The song