【摘要】 我国地下工程结构的抗震设计主要采用等效静力法,国外则提出了自由场变形法、反应位移法等方法。分析评价等效静力法、自由场变形法和反应位移法应用于软土地下结构抗震设计的差异。分析中设定表征软土地下结构的基准模型,并以动力时程分析给出地下结构的地震响应。假定地质条件和结构埋深不变,通过比较分析随基准模型的结构刚度变化时计算变形和内力的差异,评价三种拟静力地下结构抗震设计方法的适用性。结果表明,等效静力法对刚度较大的浅埋框架结构适用性较好,其它情况计算的结构变形和内力偏大;自由场变形法适用于浅埋框架结构刚度较小或与周围地层刚度接近的情况,且倒三角形分布力模式优于集中力模式;反应位移法可适用于不同刚度软土浅埋框架结构的抗震设计。更多还原

【Abstract】 The discrepancies between seismic designs with equivalent static method(mainly used in China), free-field deformation method and response displacement method(mainly used in foreign countries) were analyzed and evaluated. In analysis, the benchmark model was set up for underground structure in soft soil, and the seismic response of underground structure was acquired by using dynamic time-history analysis. Assuming the same stratum and the same buried depth, based on the discrepancy comparison analysis of different deformations, internal forces, and structural stiffnesses, evaluation of applicability was made for the three pseudo-static seismic design methods. The result shows: equivalent static method can be applied well under the condition of large stiffness of shallow-buried frame structures in soft soil, however in other cases it will lead to over-large deformation and internal force in structure; free-field deformation method can be applied under the condition that the stiffness of structure is relatively small or approaches to that of the surrounding soil; and the pseudo-triangular pressure distribution model is prior to pseudo-concentrated force model; and response displacement method is suitable for seismic design of shallow-buried frame structures with various stiffnesses.更多还原