In seismic hazard studies, the Horizontal-to-Vertical Spectral Ratio (HVSR) is nowadays routinely considered as a quick way to assess possible amplification effects. However, because of several issues that can affect the data, the HVSR cannot be considered as valid per se, and a careful data evaluation is necessary. In this study, a series of HVSR curves are evaluated in order to highlight industrial components that can significantly alter the natural HVSR. First, a controlled-source experiment is carried out in order to define the characteristics of spurious industrial signals. Data analysis shows that the coherence functions and the mildly smoothed amplitude spectra plotted with linear scales can help significantly in identifying industrial components that can be otherwise difficult to highlight. Coherence functions appear particularly interesting because of their ability to reveal the presence of industrial components independently of their amplitude. Field data from three sites are then analyzed on the basis of the evidence obtained through the controlled-source experiment. For the third site, data recorded on two different days are considered. While in the first data set no significant industrial component is present, in the second and third data sets, a series of remarkable industrial signals that severely alter the natural HVSR are identified. The assessment of the coherence functions and mildly smoothed amplitude spectra is therefore suggested as a valuable support to avoid pitfalls in the interpretation of the experimental HVSR. Finally, two quick and dirty procedures aimed at reducing the effect of industrial components are also presented.

中文翻译：

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从微震中识别水平垂直光谱比 (HVSR) 中的工业组件

在地震灾害研究中，水平垂直光谱比 (HVSR) 现在通常被认为是评估可能的放大效应的快速方法。但是，由于可能影响数据的几个问题，HVSR 本身不能被视为有效，因此需要仔细评估数据。在这项研究中，评估了一系列 HVSR 曲线，以突出显示可以显着改变自然 HVSR 的工业组件。首先，进行受控源实验以定义杂散工业信号的特性。数据分析表明，相干函数和用线性标度绘制的温和平滑的幅度谱可以显着帮助识别可能难以突出显示的工业组件。相干函数似乎特别有趣，因为它们能够独立于振幅来揭示工业组件的存在。然后根据通过受控源实验获得的证据分析来自三个地点的现场数据。对于第三个站点，考虑在两个不同日期记录的数据。虽然在第一个数据集中不存在重要的工业成分，但在第二个和第三个数据集中，确定了一系列严重改变自然 HVSR 的显着工业信号。因此，建议对相干函数和温和平滑的幅度谱的评估作为避免实验 HVSR 解释中的陷阱的宝贵支持。最后，