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国家地震局工程力学研究所与美国加州理工学院(C.I.T.),南加州大学(U.S.C.)以及地质调查局(U.S.G.S.)于1981年正式开始了一项中美双边强震观测的合作研究计划。作为这项计划的一部分,1982年6月底在中国唐山地震(1976.7.28,M_s=7.8)的余震区,布设了一个实验性的强震仪器台阵。这个台阵由12台三分量数字磁带记录式强震仪组成。从1982年7月至1983年3月,该台阵共取得了震级M_L=1.2—6.2的133个地震的285张近场加速度记录,其中大部分保留了初至P波和相应的精确到时。 本文介绍了实验台阵的运行情况和所获取的典型的近场加速度记录,展示了1982年10月19日卢龙M_L=6.2地震时距震中仅4公里的地点所获取的十分珍贵的近场加速度记录,其水平向最大加速度为0.23g,竖向最大加速度为0.128g。 本文还根据所获取的资料,进行了初步分析,给出了有关震源情况的若干基本数据和近场地震动的衰减规律。
The Institute of Engineering Mechanics of the State Seismological Bureau and the U.S.I. California Institute of Technology (C.I.T.), the University of Southern California (U.S.C.), and the U.S. Bureau of Geological Survey officially began a joint research project on bilateral strong earthquakes in 1981. As part of this project, an experimental strong seismic array was deployed at the aftershock zone of the Tangshan earthquake in China (1976.7.28, M_s = 7.8) at the end of June 1982. The array is composed of 12 three-component digital tape recorder-type seismometers. From July 1982 to March 1983, a total of 285 near-field acceleration records of 133 earthquakes with Magnitude M_L = 1.2-6.2 were obtained. Most of them retained the first-arrival P-wave and the corresponding accurate arrival time . This paper presents the operation of the experimental array and the typical near-field acceleration records obtained. It shows the very precious near-field obtained from a location just 4 km from the epicenter of the MLC L_L 6.2 earthquake on October 19, 1982 Acceleration recording, the horizontal maximum acceleration of 0.23g, vertical maximum acceleration of 0.128g. Based on the obtained data, this paper also makes a preliminary analysis and gives some basic data about the source conditions and the attenuation law of near-field vibration.