钢-钢筋混凝土塔式组合结构模型振动台试验研究

A shaking table test on steel-reinforced concrete composite tower

对一利用太阳能发电的钢-钢筋混凝土塔式组合结构原型进行1/18缩尺比模型设计,并开展了模型结构模拟地震振动台试验,以研究结构的抗震性能。通过分析试验中加速度响应、位移响应和应变响应,得到钢-钢筋混凝土塔式组合结构在地震激励作用下的受力性能。结果表明:钢-钢筋混凝土塔式组合结构底部在水平向地震作用下,承受巨大的剪力,最早出现严重的水平向贯通性破坏裂缝;加速度放大系数沿着结构高度升高而逐渐增大;随着台面激励加速度输入值的增大,加速度放大系数逐渐减小;位移反应随着结构高度增加而逐渐增大,塔顶结构有明显的鞭梢效应;8度罕遇地震作用下,X向最大位移172 mm;混凝土筒壁最薄处,结构应变反应最大。钢塔顶结构的塔柱底部和底部斜杆应力较大,出现了局部屈曲变形。

The 1/18 scale model of the practical engineering prototype of steel-reinforced concrete composite solar pawer tower was designed,constructed and subjected to a shaking table test to study the seismic performance of the structure. By analyzing the results of acceleration response, displacement response and strain response, a comprehensive understanding has been reached about the failure and mechanism of steel reinforced concrete composite tower under earthquake excitations. The result shows that the first horizontal penetrating fracture occurs at the bottom of tower under great shear force and the acceleration magnification factor increases gradually along the height of the structure. With the increase of the input value of the mesa excitation acceleration,the amplification factor of the acceleration decreases gradually. The displacement response increases with the height of the structure,and the tower top structure has obvious whipping effect. Under the action of eight degree amplified rare earthquake,the maximum displacement response in X-direction is 172 mm. At the thinnest part of concrete tube wall,the strain reaction of the structure is the largest. The stresses of diagonal braces at the bottom and the bottom of the column of top steel tower are largest,and the local buckling occurs at these locations.