北京大兴国际机场航站楼大跨度钢结构整体缩尺模型振动台试验研究

Shaking table test on overall-scale model of long-span steel structure of Beijing Daxing International Airport terminal

北京大兴国际机场航站楼大跨度曲面钢网格结构超长超大,支承C形柱结构形式新颖受力情况复杂。为此,设计并制作了1/60缩尺模型,通过振动台试验研究其在8度多遇、设防、罕遇地震作用下的动力特性,并分析其在单向、双向、三向地震动情况下的加速度、位移和应变等地震响应。试验结果表明:模型整体结构在三向地震动作用下反应最大,且结构受竖向地震作用影响较大,中心区竖向反应强烈,其余各区域水平地震反应均匀,模型整体性较好,支承结构应变反应受水平地震作用影响较大,具有良好的抗侧刚度;模型在8度多遇地震作用下对应层间位移角为1/639,8度罕遇地震作用下,层间位移角为1/54,满足抗震规范要求,模型在9度罕遇地震作用下没有发生倒塌和明显的破坏,验证了结构原型具有合理的安全储备,满足"小震不坏,中震可修,大震不倒"的抗震设计原则,结构设计合理。C形柱结构设计合理,具有良好的支承作用及抗侧刚度。

The long-span curved surface steel structure of Beijing Daxing International Airport terminal is super long and large,and the form of the supporting C-shaped column is novel,the structural load bearing is complex. A 1/60 scale model was designed for shaking table test to study its dynamic characteristics under the actions of 8 degree frequent,seismic precautionary and rare earthquakes. The acceleration,displacement and strain under the conditions of one-way,two-way and three-way ground motions were analyzed. The test results show that the response of the overall model is the largest under three-way ground motion,and the structure is greatly affected by the vertical seismic action.The vertical response in the central area is intense,and the horizontal seismic response in other areas is even,which shows that the integrity of the model is good. The supporting structure has good lateral stiffness and its strain response is greatly affected by the horizontal seismic action. The inter-story drift angle under the condition of 8 degree frequent earthquake is 1/639,the inter-story drift angle under the condition of 8 degree rare earthquake is 1/54,which meets the requirement of seismic code. The structure does not collapse under the condition of 9 degree rare earthquake and does not show apparent failure. It is proved that the structure prototype has reasonable safety reserve. The seismic principle that "the structure hasn’t damaged under frequent earthquake,repairable under precautionary earthquake,and doesn’t collapse under rare earthquake"is reached,thus the structural design is reasonable. The design of C-shaped column is reasonable,and it has good supporting action and lateral stiffness.