Fibre optic Distributed Acoustic Sensing (DAS) systems provide vibration response information comparable to accelerometers, geophones, and seismometers and may become widely used for infrastructure monitoring. DAS can be used to monitor earthquake activity, carbon sequestration, pipelines, and roadway/railway subgrade integrity, however little is known about the effect of soil type and burial method on DAS response. The objective of this paper is to present the results of a seven-month field study in which a DAS system was installed in different soil types (silty sand, clean sand, gravel, and a flowable fill) adjacent to an existing, decade-old DAS array. Impact tests were performed to evaluate DAS response in the different soil types and a portion of DAS array installed a decade prior. Signal-to-Noise Ratio (SNR) was used to compare performance of DAS response. Results of the monitoring program indicate that portions of the array in sand, gravel, and silty sand had good response with comparable SNR. A newer portion of array performed approximately five decibels better than the decade-old portion of DAS array, both in silty sand, with the old portion still performing well. These results may help build confidence with the geotechnical community regarding the longevity performance of DAS for infrastructure vibration monitoring.

中文翻译：

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用于基础设施监测 SNR 评估的土壤中的分布式声学传感

光纤分布式声学传感 (DAS) 系统提供的振动响应信息可与加速度计、地震检波器和地震仪相媲美，并可能广泛用于基础设施监测。DAS 可用于监测地震活动、碳封存、管道和道路/铁路路基的完整性，但对土壤类型和埋藏方法对 DAS 响应的影响知之甚少。本文的目的是展示一项为期 7 个月的实地研究的结果，其中 DAS 系统安装在不同的土壤类型（粉砂、干净的沙子、砾石和可流动的填充物）中，靠近现有的十年历史DAS 阵列。进行了冲击测试以评估 DAS 在不同土壤类型和十年前安装的一部分 DAS 阵列中的响应。信噪比 (SNR) 用于比较 DAS 响应的性能。监测程序的结果表明，沙子、砾石和粉砂中的部分阵列具有良好的响应，具有相当的信噪比。较新的部分阵列的性能比 DAS 阵列的十年前的部分好大约 5 分贝，两者都在粉砂中，旧部分仍然表现良好。这些结果可能有助于岩土工程界对 DAS 用于基础设施振动监测的寿命性能建立信心。旧部分仍然表现良好。这些结果可能有助于岩土工程界对 DAS 用于基础设施振动监测的寿命性能建立信心。旧部分仍然表现良好。这些结果可能有助于岩土工程界对 DAS 用于基础设施振动监测的寿命性能建立信心。