Soil Profiling at the Geotechnical Experimentation Site of Treasure Island, CA

横波的速度与波传播所通过的岩土材料的刚度和密度直接相关。可以将土壤沉积物的材料特性与测量的横波速度相关联；而准确的横波速度剖面被认为为评估土壤沉积物的动力响应提供了基本数据，尤其是发生强烈地震时，地面震动。现有的测量土壤沉积物中剪切波速度的方法，稳态瑞利波方法(SSRW)和表面波谱分析方法(SASW)都有其局限性。该项目的一个目标是在金银岛岩土试验现场调查一种新方法的能力，称为受控源面波谱分析(CSSASW)，它结合了表面波谱分析方法和表面波谱分析方法的特点。金银岛隶属于美国海军，是一个人工岛，毗邻旧金山湾的耶尔巴布埃纳岛。海军正在这个岛上提供一个场地，用于基础研究土壤沉积物对地震的动态响应-诱发强烈的地面运动，以及用于一般岩土工程试验-例如本项目调查CSSASW方法在现场的使用人物刻画。预计这项实验还将在金银岛遗址提供更多有价值的地下数据，这将有助于将该场地用作国家岩土工程研究设施。

The velocity of a shear wave is directly related to the stiffness and density of the geotechnical material through which the wave propagates. It is possible to correlate material properties of a soil deposit to the measured shear wave velocity; and accurate shear wave velocity profiles are recognized as providing essential data on which to evaluate the dynamic response of soil deposits, in particular to strong earthquake ground shaking. Existing methods for measuring shear wave velocities through soil deposits, such as the steady-state Rayleigh wave method (SSRW) and the spectral-analysis-of-surface-waves method (SASW), have their limitations. An objective of this project is to investigate at the Treasure Island geotechnical experimentation site the capability of a new method, referred to as the controlled-source spectral- analysis-of-surface-waves (CSSASW), which combines features of the SSRW and SASW methods. Treasure Island, which belongs to the U.S. Navy, is a man-made island adjacent to Yerba Buena Island in San Francisco Bay. The Navy is making a site on this island available for basic research into the dynamic response of soil deposits to earthquake-induced strong ground motions, and for general geotechnical engineering experiments - such as this project to investigate the use of the CSSASW method for site characterization. It is expected that this experiment will also provide additional valuable subsurface data at this Treasure Island site which will contribute to the use of this site as a national facility for geotechnical engineering research.