A Hybrid Sliding Isolation System with Controllable Friction Bearings

最近，采用计算机可控摩擦支座的混合滑移隔震系统被开发出来，并被证明比相应的传统被动滑移系统在控制单自由度系统的地震反应方面更有效。这项拟议的研究旨在通过进行一系列分析和试验研究来开发改进的隔震系统设计，从而将这种混合隔震系统的适用性扩展到多层建筑。分析工作将涉及两种控制算法的开发和计算机模拟研究，其中包括不同结构和隔震系统参数以及不同输入运动。实验工作将包括对所提议的计算机可控隔震装置进行振动台实验室测试。混合滑移隔震系统比传统的被动隔震系统更具优势，因为它对烈度范围较宽的地震更有效，而且往往更稳健。然而，要在实践中满怀信心地充分实施这一制度，似乎存在几个尚未克服的重大技术和实际问题。拟议的研究将开展：(1)改进摩擦可控轴承，适当考虑上浮的可能性及其预防，为滑动界面选择合适的材料，腔压控制，能源供应和系统维护，(2)稳健的控制算法，以满足同时控制楼层加速度、层间变形和滑移等三维众多响应的要求，并防止与建筑物相关的过度倾覆力矩和隆起问题，(3)编制统一的计算机程序包，对不同建筑模型在不同地震激励下的隔震性能进行仿真研究。这项研究还将进行部件性能的实验室测试和使用振动台进行的缩尺建筑模型测试，以及纳入实验结果所建议的变化的系统的重新设计。拟议的研究将解决创新的混合滑移隔震系统存在的剩余技术和实际问题，从而为其在地震活跃地区建造的建筑结构中的广泛应用铺平道路。

Recently, a hybrid sliding isolation system employing computer-controllable friction bearings has been developed and proven to be more effective in controlling the seismic response of a single-degree-of-freedom system than the corresponding conventional passive sliding system. This proposed research intends to extend the applicability of this hybrid isolation system to multistory buildings by conducting a series of analytical and experimental investigations to develop an improved isolation system design. Analytical work will involve development of two control algorithms and computer simulation studies with different structural and isolation system parameters and different input motions. The experimental work will involve shaking table laboratory test on the proposed computer controllable isolation devices. The hybrid sliding isolation systems are more advantageous over the conventional passive systems in that they are more effective for earthquakes with a broad intensity range, and tend to be more robust. However, to fully implement such a system with confidence in practice, there appear to exist several major technical and practical problems that are yet to be overcome. The proposed research will develop: (1) improved friction controllable bearings with proper consideration of the problems of the possibility of uplifting and its prevention, choice of the proper materials for sliding interface, chamber pressure control, energy supply, and system maintenance, (2) robust control algorithms to satisfy requirements for simultaneously controlling three-dimensional multitudinous responses, such as floor acceleration, interstory deformation, and sliding displacement, and to prevent excessive overturning moment and uplifting problems associated with buildings, and (3) a unified computer codes package to conduct simulation studies of isolation performance on various building models under different earthquake excitations. The laboratory tests for component performance and scaled building model tests using a shaking table as well as the redesign of systems incorporating the changes suggested by the experimental results will also be performed in this study. The proposed research will resolve the remaining technical as well as practical problems existing with the innovative hybrid sliding isolation system - thus paving the way for its broad applications in building structures constructed in active seismic areas.