ABSTRACT

in this study, new prediction equations are proposed to determine the variables of gamma envelope-shape Function. Envelope-shape functions are employed for the simulation of ground motion using a stochastic method in order to form the white noise. A variety of Envelope-shape functions have been already proposed, among which gamma equations are more used in computational programs for the simulation of ground motion, e.g. SMSIM or EXSIM. In addition to the detection of influential variables of gamma envelope-shape function, their relationship with important seismic criteria such as moment magnitude, closest distance to rupture plane, site conditions and mechanism of faulting are determined and suitable models are presented in this study. Limited research has been already undertaken to specify the variables of envelope-shape equations and their relationships with the main seismic criteria. Hence the results of this study can almost demonstrate this relationship with seismic criteria. The new equations are developed using Iran strong ground motion database, which includes 2228 records of 749 earthquakes that covering up to 2018. The proposed equations can be used to determine exponential window function for earthquakes with moment magnitude $M_w$ from 4.5 to 7.6 and rupture distance up to 200 km. The proposed model is compared with some existing models and the results suggest that the equations can lead to better and more reasonable results in the ground motion simulation process, particularly for the estimation of response spectrum of velocity and displacement.

摘要

在这项研究中，提出了新的预测方程来确定伽马包络函数的变量。包络形状函数用于使用随机方法模拟地面运动，以形成白噪声。已经提出了多种包络形状函数，其中伽马方程更多地用于模拟地震动的计算程序中，例如SMSIM或EXSIM。除了检测伽马包络函数的影响变量外，本研究还确定了它们与重要地震准则（如矩量级、距破裂面最近距离、场地条件和断层机制）的关系，并提出了合适的模型。已经进行了有限的研究来指定包络形状方程的变量及其与主要地震标准的关系。因此，这项研究的结果几乎可以证明这种与地震标准的关系。新方程是使用伊朗强地震动数据库开发的，该数据库包括截至 2018 年的 749 次地震的 2228 条记录。所提出的方程可用于确定具有矩震级的地震的指数窗函数${米}_w$从 4.5 到 7.6，破裂距离可达 200 公里。将所提出的模型与现有的一些模型进行了比较，结果表明该方程可以在地震动模拟过程中得到更好、更合理的结果，特别是对于速度和位移响应谱的估计。