反应位移法中地基弹簧刚度系数求解方法对比研究

Comparative Study on Solution Methods of Foundation Spring Stiffness Coefficient in Response Displacement Method

反应位移法是目前地下结构抗震设计中应用最为广泛的简化方法之一,其中的一个关键参数是结构周围弹簧刚度系数。基于《城市轨道交通结构抗震设计规范》(GB 50909—2014)中简化的静力有限元法,进行了不同加载形式的静力有限元刚度法和柔度法计算弹簧刚度系数,将其计算结果应用于反应位移法与严格的动力时程计算结果进行对比研究。结果表明:不论静力有限元刚度法还是柔度法,除水平竖直加载方式外,其余的加载方式确定的地基弹簧系数对反应位移法计算的结构变形及内力影响较小。考虑计算次数,可以采用刚度法和柔度法中的径向切向和径向环向一次加载方式对静力有限元法进行简化计算。

Response displacement method is one of the most widely used simplified methods in seismic design of underground structures.One of the key parameters in the method is the spring stiffness coefficient around the structure.Based on the simplified static finite element method in the Code for Seismic Design of Urban Rail Transit Structures(GB50909-2014),the static finite element stiffness method and the flexibility method were used to calculate the spring stiffness coefficient with different loading forms.The calculation results were applied in response displacement method.The calculated internal structural forces and deformations are compared with the calculation results of strict dynamic time history method.The results show that the spring stiffness coefficient obtained by both the static finite element stiffness method and the flexibility method have little influence on structural deformation and internal force calculated by the response displacement method regardless of the loading forms except for horizontal and vertical loading forms.Considering the number of calculations,the static finite element method can be simplified by the radial tangential one-time loading method and the radial circumferential one-time loading method.