临沂启阳机场航站楼屋盖单双层混合曲面网格结构设计

Design of single-layer and double-layer hybrid cambered grid structures used in Linyi Qiyang airport terminal roof

为实现大跨度无柱空间及中部上隆的建筑形态,对临沂启阳机场航站楼屋盖结构采用单、双层混合曲面三向网格体系。该屋盖结构总平面尺寸为243 m×180 m,其中单层网壳尺寸为72 m×48 m,曲面形状通过数值逆吊找形获得。整体屋盖由56根斜柱支撑,最大跨度约为83 m,最大悬挑约为20 m,柱顶支座采用固定铰支座和单向弹性铰支座两种型式。针对屋盖结构的特点,采用数值模拟进行了静力性能分析、整体稳定性全过程分析、抗震分析及关键节点分析。分析结果表明:由数值逆吊确定的单层网壳主要通过面内路径传递荷载,同时双层部分可提供较理想的边界支撑条件,使单层网壳面内力能够可靠传递,整体结构受力合理;空侧设置20个单向弹性铰支座能够调节刚度不均匀引起的扭转效应,同时能够较好的释放温度变形,降低结构温度应力;为确保安全,在进行整体稳定性全过程分析时,考虑了多种初始缺陷模态及温升的不利影响,屋盖结构整体稳定性安全系数为2.88;罕遇地震作用下,单层网壳具备较高的安全储备,杆件损伤主要发生在网格高度较大的双层区域及悬挑区域,且塑性发展程度较低;单层网壳和单、双层网壳过渡区的关键节点具备适宜的安全储备,满足强节点的设计原则。

The single-layer and double-layer hybrid cambered grid structure is used in Linyi Qiyang airport terminal roof to realize the large-span column-free space and the architectural form of the uplift in the middle.The total plane size of the roof structure is 243 m×180 m,of which the size of the single-layer reticulated shell is 72 m×48 m,and the shape of the curved surface is obtained by numerical inverse hanging method.The whole roof is supported by 56 inclined columns.The maximum span and cantilever span of the roof is 83 m and 20 m,respectively.The roof adopts two types of bearings,including unidirectional elasticity hinge bearings and fixed ball joint bearings.Bearing capacity analysis,overall stability analysis,earthquake resistance analysis and key joint analysis are conducted for the roof structure using simulation method.The main results are as follows.The single-layer reticulated shell determined by numerical inverse hanging method mainly transmits load through the in-plane path,while the double-layer part can provide ideal boundary support conditions,so that the shell thrust can transmit the internal force reliably.The 20 unidirectional elasticity hinge bearings set at air-side can adjust the torsion effect caused by stiffness irregularity,and release the temperature deformation to reduce the structure temperature stress.Various initial imperfection modes and unfavorable action of temperature rise are considered in the overall stability analysis,and the overall stability safety factor of the roof structure is 2.88.The single-layer reticulated shell has a high safety reserve subjected to the rare earthquake;the damaged components are mainly distributed in the double-layer part with larger height and the cantilever region with less plastic development.The key joints in the single-layer reticulated shell and transition region have appropriate safety reserve,which satisfy the design principle of strong connection.