复杂非均质场地中核安全抗震Ⅰ类桩基结构楼层反应谱研究

Study of the floor response spectra of the structure used pile foundation classified of seismic category I in the non-homogeneous field

近年来随着核工程领域的快速发展,理想的基岩厂址越来越少,核工程建设场址选择逐渐由基岩场地向非基岩场地过渡将成为必然趋势。传统的技术方案已经不能满足抗震Ⅰ类结构对地基的要求,为了保障核工程的可持续发展,地基问题亟待解决。桩基技术在一般的工业与民用建筑领域的应用已经十分广泛和成熟,由于核工程的特殊性,民用桩基规范中相关标准难以解决核工程桩基面临的技术难题,进而限制了桩基在核工程领域的应用。制约桩基在核安全抗震Ⅰ类结构上应用的主要技术难题是桩-土-结构动力相互作用问题。选取国内首个位于复杂软土地基上的核安全抗震Ⅰ类结构,首先采用国内外规范中认可度较高的p-y曲线法,分析了桩-土-结构体系的地震动力响应,获得了楼层反应谱和各项动力性能指标,然后采用三维完全法验证了p-y曲线法的保守性。在国内首次采用桩基础解决了实际工程中核安全抗震Ⅰ类结构地基问题,为桩基础在核工程领域的推广和应用提供了有价值的参考,对于进一步拓展核工程厂址的选址范围具有重要意义。

In recent years,with the rapid development of the nuclear engineering fields,the ideal bedrock site has been less and less,and the transition from bedrock to non-bedrock site will be the inevitable trend.The traditional technical solution can not met the requirements of the structure classified of seismic category I.In order to ensure the sustainable development of nuclear engineering,the problem of foundation is needed to be solved urgently.The application of pile foundation technology in general industrial and civil construction areas is very broad and mature.Due to the particularity of the nuclear engineering,the relevant provisions of the civil pile foundation are difficult to solve the technical problems facing the nuclear engineering pile foundation,which in line limit the application of the pile foundation in the field of nuclear engineering.The main technical problem of the application of the pile foundation in the nuclear safety seismic I structure is the problem of the pile-soil-structure dynamic interaction.The first nuclear safety seismic I structure in China is selected.By using the high degree of the p-y curves method,the seismic dynamic response of the pile-soil-structure system was analyzed,and the floor response spectrum and various dynamic indexes were obtained.Finally,a three-dimensional complete method is used to verify the conservatism of the p-y curves.Pile foundation is adopted to solve the problem of the foundation of nuclear safety seismic I structure in the actual project,which is the first case in China,providing valuable reference for the promotion and application of the pile foundation in the field of nuclear engineering,and of great significance to further expand the range of the nuclear engineering site.