设防烈度对框架—核心筒结构受力性能和材料用量的影响

为了考察设防烈度对钢筋混凝土框筒结构受力性能、材料用量的影响,在充分调研了目前我国100 m以上已建或在建超高层建筑的基础上,选择150~300 m范围内钢筋混凝土框架—核心筒办公类超高层作为代表性研究对象,建立了12个不同烈度、不同高度下的计算模型,详细分析了其结构的周期比、剪重比、刚重比、地震作用和风荷载影响等结构受力性能以及结构的用钢量、混凝土用量随设防烈度的变化情况.研究结果表明,对于济南恒大国际金融中心工程,随着设防烈度的提高,结构自振周期减小,扭转周期滞后于平动周期,扭转效应减小,而结构剪重比明显增加;低烈度地区结构受重力二阶效应的影响较大,整体稳定性成主要安全控制因素;地震作用的影响随设防烈度的增加而增大;6度区建筑超过200 m后,用钢量明显增加,而8度区用钢量随建筑高度呈线性增长;6度和7度区单位面积混凝土用量接近,而8度区混凝土用量增幅约为19%左右,所以设防烈度对结构工程材料用量影响显著.

Influence of fortification intensity on structural performance and material dosage of frame-tube structures

To determine the effect of fortification intensity on the mechanical properties and amount of material used in reinforced concrete frame-tube structures, high-rise buildings over 100 m in height that were either built or being built were researched. 12 mod-els of high-rise office buildings ranging from 150 m to 300 m in height and with different seismic intensities were analyzed, with respect to their period ratios, shear-weight ratios, stiffness-weight ratios, earthquake and wind-load influences, and the costs of steel and con-crete for different fortification intensities. The results show that for the Jinan International Finance Center Landmark Tower, with in-creasing fortification intensity, the natural vibration period of the structure decreases, the torsion period lags behind the vibration peri-od, the torsional effect reduces, and the shear-weight ratio significantly increases. Structures with low fortification intensities are great-ly influenced by gravity as a second-order effect and their entire stability becomes the main safety control factor. The influence of earth-quake action increases with increased fortification intensity. In the region with seismic fortification intensity 6 (0. 05 g), steel con-sumption for buildings over 200 m in height increases significantly and in the intensity region 8 (0. 20 g), steel consumption has linear growth with height. The concrete dosage in unit area in intensity region 6 (0. 05 g) is close to that in intensity region 7 (0. 10 g), and increases by about 19% in intensity region 8 (0. 20 g). As such, the influence of fortification intensity is significant with respect to structural material dosage.