一种模拟随机数字地层模型的方法

介绍了一种利用计算机生成随机数字地层模型的方法。此方法根据给定的地层厚度及参数统计特性．按截尾正态分布进行随机抽样构建随机分层结构，并对各分层参数随机赋值，完成随机模型的构筑。用此方法可以很容易地在计算机上生成大量符合某种统计特性的随机数字层状地层模型，从而可以在这些模型上进行感兴趣的仿真模拟研究。为展示这一方法的应用，生成了10个第四系随机层状模型，并在这些模型上进行了地震SH波的地震动放大效应数字模拟实验。结果发现随机模型的响应无论在形态特点还是幅值上都与均值模型的响应显著不同，表明用不完全准确的参数模型模拟估计场址地震动响应时必须充分考虑到参数不准导致的误差。

A Method for Modelling Randomly Layered Earth Models

A method is developed for the synthesis of randomly layered earth models on a computer. According to estimated statistical characteristics of a model to be built, random numbers sampled from truncated normal distributions, which are determined by the given estimates, are generated to construct the randomly layered structure and determine medium parameters for the layers. Using this method, large number of random models can be efficiently generated, on which simulation of phenomenon of interest can be performed for study purposes. To demonstrate its application, 10 random Quaternary models were synthesised using the method. Modelling of SH wave propagation was performed on each model to study the seismic ground motion amplification of the structure. The results show that the responses of the random models are significantly different from that of the mean model. This indicates that uncertainties in model parameters would lead to significant variation in modeling outputs. Therefore, statistics over modeling outputs of large number of random models can be a useful strategy to estimate the modeling output when there are uncertainties in model parameters. Thus the method introduced in this paper provides an efficient means for the generation of random models for the purpose.