Forced Vibration Tests of the Foundation and Surrounding Soil at the NEES Large High Performance Shake Table

该措施旨在支持在加州大学圣地亚哥分校Elliott营地的国家地震工程模拟（NEES）大型高性能振动台附近的钢筋混凝土基础块和土壤的强迫振动试验。 目的是获得关于利用土壤刚度和辐射阻尼的概念的基本信息，以减少对超大型和深埋基础抵抗动载荷和静载荷的必要性。试验将在基础和邻近土坑的开挖完成后进行，并在钢筋混凝土基础块完成后再次进行。 这将与加州大学洛杉矶分校NEES现场试验设施和墨西哥恩塞纳达恩塞纳达上级科学研究和教育中心（CICESE）的研究人员合作完成。 在初始测试中，偏心质量振动器将放置在开挖底部，用于振动台的基础块和相邻设备厂房的基础。 将对基础空腔、相邻土坑和地面上200米距离处密集阵列的动态响应进行测量。 在振动台的基础块和设备厂房的基础完成后，将重复进行测试。该项目的第一个目标是利用有限的时间窗口获得动态地面运动数据，并通过推理获得岩土数据，用于开发埃利奥特营地的完整NEES大型高性能振动台设施的虚拟模型。 第二个目标是验证一种新的设计方法，基础受到的冲击载荷，使用土壤刚度和辐射阻尼，以取代部分的基础块，导致一个更经济的安装。 如果得到充分验证，这一方法将利用土壤-地基动力相互作用分析方面的进步，从而节省大量资金，该项目将在密集城市环境中模拟结构的地震和振动反应方面发挥重要作用。 该项目将为本科生和研究生提供一个独特的培训机会。学生，将是有益的研究成果整合到本科和研究生课程的岩土工程和地震工程，并将测试远程观测能力从加州大学圣地亚哥分校NEES网站在营埃利奥特。

This action is to support forced vibration tests of the reinforced concrete foundation block and of the soils in the vicinity of the National Earthquake Engineering Simulation (NEES) Large High-Performance Shake Table at Camp Elliott, University of California-San Diego. The objective is to obtain fundamental information on the concept of using soil stiffness and radiation damping to reduce the necessity for extremely massive and deeply embedded foundations to resist dynamic and static loading.The tests will be conducted upon completion of the excavation for the foundation and the adjacent soil pits, and again, after completion of the reinforced concrete foundation block. This will be done in collaboration with researchers associated with the NEES Field Testing Facility at UCLA and with the Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), Ensenada, Mexico. In the initial tests, eccentric mass shakers will be placed at the bottom of the excavations for the foundation block of the shake table and for the foundation of the adjacent equipment building. Measurements will be made of the dynamic response at dense arrays on the cavities for the foundations, on the adjacent soil pit and on the ground surface up to a distance of 200 meters. The tests will be repeated after the foundation block for the shake table and the foundation for the equipment building have been completed.The first objective of the project is to take advantage of limited time-windows to obtain dynamic ground motion data and, by inference, geotechnical data to be used in the development of a virtual model of the complete NEES Large High-Performance Shake Table facility at Camp Elliott. The second objective is to validate a new design approach for foundations subjected to impact loads that use soil stiffness and radiation damping to substitute for part of the foundation block, leading to a more economical installation. If fully validated, this approach, which takes advantage of advances in analysis of dynamic soil-foundation interaction, will result in significant savings.The project will play an important role in efforts to model the seismic and vibration response of structures in dense urban environments. The project will provide a unique training opportunity for undergraduate and graduate. students, will be useful in integrating the results of research into undergraduate and graduate courses on geotechnical and earthquake engineering, and will test the tele-observation capabilities from the UCSD NEES site at Camp Elliott.