Abstract Multichannel analysis of surface wave (MASW) surveys are commonly used onshore to produce shear wave velocity (Vs) profiles. This paper describes its use in offshore geotechnical investigations (underwater MASW - UMASW) where the focus was on the upper 15 m of the sediment profile to aid the design of structures such as marine pipelines, cable routes and shallow anchor systems. UMASW was shown to provide reliable data in Irish offshore conditions in water depths of up to 50 m. The receiver spacing and array length, rather than the characteristics of the air gun seismic energy source, were the primary control on signal penetration and resolution of individual sediment layers. Good resolution of the properties of the upper 5 m of sediment was found by reducing the receiver spacing to as low as 0.3 m. A test site, with a broad intertidal zone, allowed coincident land, marine and direct measurements to be compared and Vs profiles obtained from UMASW, onshore MASW and by seismic cone testing (SCPTU) were in good agreement. Vs profiles estimated from published correlations with CPTU data in sandy sediments agreed well with the measured values. Inversion of data using different software packages showed only a minor variation in results.

中文翻译：

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用于海上岩土工程调查的表面波多通道分析 (MASW)

摘要 表面波 (MASW) 调查的多道分析通常在陆上用于生成横波速度 (Vs) 剖面。本文描述了它在近海岩土工程调查（水下 MASW - UMASW）中的使用，其中重点放在沉积物剖面的上部 15 m，以帮助设计海洋管道、电缆路线和浅锚系统等结构。UMASW 被证明可以在爱尔兰近海条件下提供高达 50 m 水深的可靠数据。接收器间距和阵列长度，而不是气枪地震能量源的特性，是单个沉积层的信号穿透和分辨率的主要控制因素。通过将接收器间距减小到 0.3 m，发现沉积物上部 5 m 的特性具有良好的分辨率。一个测试站点，具有宽阔的潮间带，允许对重合的陆地、海洋和直接测量进行比较，并且从 UMASW、陆上 MASW 和地震锥测试 (SCPTU) 获得的 Vs 剖面非常一致。根据已发表的与砂质沉积物中 CPTU 数据的相关性估计的 Vs 剖面与测量值非常吻合。使用不同软件包的数据反演结果仅显示出微小的变化。