【摘要】 通过对现有中小学室内活动馆建筑功能和结构形式的调研,确定了10个有代表性的不同跨度、下部结构、支座连接形式的结构模型作为分析对象,考察其屋盖网架结构的弹塑性地震响应特点.各模型中的网架结构由非地震工况下的满应力优化设计确定,且均考虑与下部结构共同工作.杆单元采用能够同时考虑受拉屈服和受压屈曲的等效弹塑性滞回模型.多遇地震作用下的结构验算采用振型分解反应谱法,设防烈度地震及罕遇地震下结构的弹塑性动力响应计算采用非线性时程法,地震波采用由规范反应谱生成的三向人工波和两条天然波.根据计算结果,统计了网架模型在7度(0.1g)、8度(0.2g)设防烈度地震和罕遇地震下塑性杆件的分布、塑性应变大小和结构残余变形,并分析了主要影响因素.研究表明,小跨度网架结构在7度和8度中震、大震作用下均未出现塑性杆件,而中等跨度网架结构会出现一定数量的塑性杆件,其分布区域与下部结构刚度有关,且大多出现在临支座区域.地震波及其输入方向对塑性杆件数量和塑性应变大小有一定影响.所有模型在大震下均未发生倒塌.更多还原

【Abstract】 Based on the analysis of architectural function and structural form of indoor stadiums in exisiting primary and middle schools,10 typical structural models with different span,connection condition of abutment and layout of substructure are employed to investigate the elasto-plastic seismic responses of their grid roof structures.The grid structure in each model is determined by the full-stress design under non-seismic load cases,and the interaction with substructure is considered.An equivalent elasto-plastic hysteretic model,which can deal with both tensile yielding and compressive buckling of bar element,is used.For frequently occurred earthquakes,all models are checked by mode response spectrum method.Structural elasto-plastic dynamic responses under fortification intensity and rare earthquakes are calculated by nonlinear time-history method,and a three-direction artificial earthquake wave generated by code response spectrum and other two natural seismic waves are adopted.According to calculation results,the distribution of plastic members,the magnitude of plastic strain and the structural residual deformation of these models are summarized,respectively for 7degree(0.1g)and 8degree(0.2g)fortification intensity and rare earthquakes,and their influencing factors are analyzed.The results reveal that plastic members never appear in small-span grid structures under 7degree and 8degree fortification intensity and rareearthquakes.A certain amount of plastic members occurs for medium-span grid structures. The distribution of plastic members is closely related to the stiffness of substructure,and mainly in the region near abutments.Seismic wave and its direction have certain influences on the quantity of plastic members and magnitude of plastic strain.Collapses never happen for all models under rare earthquakes.更多还原