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

横波的速度与横波传播所经过的岩土材料的刚度和密度直接相关。将土壤沉积物的物质性质与测量到的横波速度联系起来是可能的；准确的横波速度曲线被认为是评估土壤沉积物动力响应的重要数据。特别是强烈地震时地面晃动。现有的测量土壤沉积物中横波速度的方法，如稳态瑞利波法（SSRW）和表面波谱分析法（SASW），都有其局限性。该项目的一个目标是在金银岛岩土工程试验场调查一种新方法的能力，即可控源表面波光谱分析（CSSASW），它结合了可控源表面波光谱分析和可控源表面波光谱分析方法的特点。美国海军所属的金银岛是位于旧金山湾的芳草地岛（Yerba Buena）附近的人工岛。海军正在这个岛上的一个地点进行基础研究，研究土壤沉积物对地震引起的强地面运动的动态反应，以及一般岩土工程实验，例如本项目，研究使用CSSASW方法进行场地表征。预计这次实验还将为这个金银岛遗址提供额外的有价值的地下数据，这将有助于将这个遗址用作国家岩土工程设施工程研究。

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.