【摘要】 考察了双层球面网壳按设防烈度进行抗震设计的合理性。以24个典型双层球面网壳模型为算例,将其构件截面分别按满足"小震弹性"、"中震不屈服"和"中震弹性"进行验算,分析了网壳用钢量的变化。进一步对满足中震验算的各算例模型进行罕遇地震下的弹塑性时程分析,其中地震动采用由规范反应谱生成的三向人工波。考察了网壳跨度、矢跨比、支座连接条件以及下部结构形式对结构塑性区域、塑性发展程度以及残余变形的影响。结果表明,即便是将双层球面网壳的构件截面验算提高到满足"中震弹性"的性能水平,也并不会引起结构用钢量的显著增加,同时又能满足了"中震可修"和"大震不倒"的设防要求。更多还原

【Abstract】 The rationality is investigated for double-layer spherical reticulated shells which are designed on the basis of seismic precautionary intensity.The 24 typical double-layer spherical reticulated shell models are employed as illustrative examples.The cross sections of their members are designated to be satisfied with the check for "elastic design under frequent-occurred earthquake","non-yielding design under seismic precautionary intensity" and "elastic design under seismic precautionary intensity"respectively,and structural steel consumptions are compared correspondingly.For those models satisfied with the check seismic precautionary intensity,their elasto-plastic dynamic responses under seldom occurred earthquake are also calculated based on time-history analysis.A three-direction artificial earthquake wave generated according to the code response spectrum is adopted.The structural plastic region,magnitude of plastic strain and residual deformation effected by the span of shell,rise-span ratio,connection condition of abutment and layout of substructure are further analyzed.The results reveal that the structural steel consumption increases very limitedly even though the member cross sections of double-layer reticulated shells are checked according to the performance level of "elastic design under seismic precautionary intensity".Meanwhile,the fortification requirements of "repairable under moderate earthquake" and "no collapsing under seldom occurred earthquake" are also satisfied.更多还原