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本文提出了以全球伸展构造区记录的地震动数据为基础,而导得的预测水平峰值加速度和5％阻尼比拟速度反应谱的新关系。这个称为“Sea96”的新的经验关系最初是Spudich等(1996)得出的,那是内华达州Yucca山拟建中的核废料站场址地震危险性评估项目中的一部分。由于该报告较长,不易阅读,这里对Sea96及其推导作一简要介绍。 这个关系是根据伸展区矩震级5级以上的地震,且距离小于105公里的地震动观测数据得到了。伸展区是指岩石圈范围扩张的地区,这一范围的扩张是作用力的结果,该力使应力状态S_v>S_(Hmax)>S_(Nmin),此处S_v、S_(Hmax)和S_(Hmin)表示近垂直方向和两正交水平方向的主应力。这些术语在MoGrarr和Gay(1978)的论著中有定义。除了诸如现代大地测量和原位应力测量提供了这些范围扩张的明显证据外,伸展区通常还表现出部分或全部下列特征:正断层破裂兼走滑的地震(本研究中包括了具有这两种机制的地震)、近代火山活动、串球状分布的火山、岩石圈变薄及高热流值。 本文之所以仅限于使用伸展区地震动数据,有两个原因。第一,有观测的证据表明,压力状态,即伸展或挤压会影响地震中地面运动的幅值(McGarr, 1984; Abrahamson, 1993. Boore等,1994; Campbell和Bozorgnia, 1994)。McGarr(1984)提出,正断层
This paper presents a new relationship between the predicted level peak acceleration and the 5% damping rate response spectrum based on the ground motion data recorded in the global stretching tectonic zone. This new empirical relationship, known as Sea96, was originally drawn by Spudich et al. (1996) as part of a seismic hazard assessment of the proposed site for a nuclear waste station at Yucca Hill in Nevada. As the report is longer and less readable, here is a brief overview of Sea96 and its derivation. This relationship is based on earthquakes with an M≥5 scale in the extension zone and ground motion observations at distances of less than 105 km. The extensional zone refers to the area where the lithosphere has been expanded. The expansion of this area is the result of the force that makes the stress state S_v> S_ (Hmax)> S_ (Nmin), where S_v, S_ (Hmax) and S_ Hmin) represents the principal stress in the nearly vertical direction and the two orthogonal horizontal directions. These terms are defined in the treatises of MoGrarr and Gay (1978). In addition to the obvious evidence that these range expansions provide such modern geodetic and in-situ stress measurements, the extensional zones often exhibit some or all of the following characteristics: Normal-fault rupture and strike-slip earthquakes (in this study, Mechanism of earthquakes), modern volcanic activity, spheroidal volcanic distribution, lithospheric thinning and high heat flow values. The reason why this article is limited to the use of stretch ground motion data for two reasons. First, there is observational evidence that stress conditions, ie stretching or crushing, can affect the magnitude of ground motion in earthquakes (McGarr, 1984; Abrahamson, 1993. Boore et al., 1994; Campbell and Bozorgnia, 1994). McGarr (1984) suggested that normal faults