为探究土体性质及结构尺寸对反应位移法中基床系数的影响，分别讨论土体弹性模量、结构宽高比、结构埋深比、结构基岩比与基床系数之间的关系，并在此基础上提出了计算基床系数的简化公式。将简化公式应用于均质场地和成层场地两种条件下的地铁车站抗震分析，并与《城市轨道交通结构抗震设计规范》（GB 50909—2014）中推荐的静力有限元方法进行对比。研究结果表明基床系数与土体弹性模量之间为线性相关关系，结构宽高比的变化对结构侧墙和底板基床系数影响较大。与日本规范方法和板宽修正法相比，所提出的简化公式计算的结构内力在均质场地和成层场地中均与中国规范方法计算的结构内力更为接近，说明该公式对于基床系数的计算有很好的适用性，可为地下结构抗震分析提供参考。

To investigate the influences of soil properties and structural dimensions on the foundation coefficients in the response displacement method, the relationships between the foundation coefficients and elastic modulus of the soil, height-to-width ratio, burial ratio, and rock ratio of the structure were systematically analyzed. Then a simplified formula was proposed for calculating the foundation coefficients. The simplified formula was evaluated by applying it to the seismic analyses of subway stations under both homogeneous and layered sites, with comparative with the static finite element method recommended in the Code for Seismic Design of Urban Rail Transit Structures (GB 50909-2014). The research results show that the foundation coefficients exhibit a linear relationship with elastic modulus of soil. The height-to-width ratio of structure has a significant impact on the foundation coefficients of sidewall and bottom slab. Compared with the method in Japanese standards and the method modified by the width of slab, the structural internal forces calculated by the proposed simplified formula are more similar with those obtained by the method in Chinese code in both homogeneous and layered sites. It indicates that the proposed formulas have good applicability for calculating the foundation coefficients and can provide reference for seismic analysis of underground structures.