The Lucerne Valley Strong Ground Motion Record from the Lander's Earthquake of June 28, 1992

1992年6月28日发生的7.5级兰德斯地震记录了大量强地面运动和结构响应加速度图，这是自1952年以来加州发生的最大地震。由于震中位置偏远，工程结构受损相对较小。然而，从这次事件中获得的地面运动记录是迄今为止最重要的测量记录之一，特别是南加州爱迪生公司（SCE）安装和维护的自由场仪器的记录。这台仪器位于卢塞恩山谷，距离地表破裂大约一英里，因此提供了美国大地震最近的近场记录之一。对这一记录的初步分析表明，在位移中有一个非常明显的长周期脉冲，振幅约为120厘米。这种类型的地面运动可能对大型结构的响应产生严重影响。多年来，人们一直假定大地震近场存在明显的长周期运动，并提出了分析模型来描述这种近场运动。然而，没有足够的数据来证实这种运动的存在或性质。对卢塞恩谷（SCE）记录的初步分析提供了明显的强相关长周期运动的证据，这引起了地震工程师的极大兴趣和关注。该项目的目标是：(1)对场地、仪器和记录数据进行深入研究，以确定卢塞恩谷地震记录的准确性；(2)为该仪器开发适当的校正算法，并将其应用于测量到的地面运动记录；(3)研究Lucerne山谷的特征，记录任何可用的可比数据，以便更好地了解近场地震对结构反应的可能影响。

A large number of excellent strong ground motion and structural response accelerograms were recorded during the M 7.5 Landers earthquake of June 28, 1992, which was the largest to occur in California since 1952. There was relatively little damage to engineered structures due to the remote location of the epicenter. However the ground motion records obtained from this event are among the most significant measured to date, and especially the recording from a free-field instrument installed and maintained by the Southern California Edison Co. (SCE). This instrument was located in Lucerne Valley within approximately one mile of the surface rupture, thus providing one of the closest near- field recordings of a major U.S. earthquake. A preliminary analysis of this record shows a very pronounced long-period pulse in the displacement with an amplitude of about 120 cm. This type of ground motion could have a serious effect on the response of large structures. The existence of significant long-period motion in the near-field of a large earthquake has been postulated for some years and analytical models have been proposed to characterize this near-field motion. However there has been insufficient data with which to verify either the existence or the nature of this type of motion. The evidence of significant strongly correlated long-period motion provided by a preliminary analysis of the Lucerne Valley (SCE) record is of very great interest and concern to earthquake engineers. The objective of this project is: (1) to undertake a thorough study of the site, the instrument, and the recorded data so as to determine the accuracy of the Lucerne Valley earthquake record, (2) to develop appropriate correction algorithms for this instrument and to apply these to the measured ground motion record, and (3) to study the characteristics of the Lucerne Valley record any available comparable data to obtain a better understanding of the possible effects of near-field earthquakes on structural response.