长沙某商业综合体结构设计

Structural design of a commercial complex in Changsha

长沙某商业综合体建筑结构体型较为复杂,存在转换柱、斜柱、楼板大开洞、大跨度、大悬挑、跨地铁连廊、结构超长、多梁交汇等设计难点。转换柱根据结构的跨度及荷载需求采用型钢梁和混凝土支撑两种方式,倾斜角15°以内的斜柱采用普通钢筋混凝土柱,15°~30°的斜柱采用型钢混凝土柱;大跨度及大悬挑结构采用型钢梁及预应力梁,东西商跨地铁连廊、过街连廊、采光顶分别采用钢桁架、大跨钢梁、单层网壳处理。在部分楼梯间位置增设了混凝土斜撑,控制结构的周期比不大于0.9。采用YJK软件分析了楼板舒适度及温度应力,对多梁交汇节点增设环梁或改用钢管混凝土柱与短钢梁连接确保复杂节点混凝土浇筑质量;对结构进行了大震弹塑性时程分析,结果表明大震作用下结构处于基本完好的状态。

A commercial complex structure is complicated in Changsha,and there are design difficulties such as transfer column,inclined column,floor slab with large opening,large span,large cantilevered,corridor across the subway,super long structure,and multi-beam intersection.The transfer column can choose steel beams and concrete support structures according to the span and load conditions of the structure.When the angle is within 15°,the inclined column adopts an ordinary reinforced concrete column.When the angle is in the range of 15°~30°,the inclined column adopts steel reinforced concrete column.In this project,steel beams and prestressed beams were used to solve large span and large cantilever structures.The east-west commercial corridor across the subway,the street crossing corridors and the daylighting roof were treated with steel trusses,large-span steel beams,and single-layer latticed shells,respectively.Concrete diagonal bracing were added in some stairwells,which controlled the period ratio of the structure to not greater than 0.9.The comfort and temperature stress of the floor slab by YJK software were analyzed.For multi-beam junctions,the project added ring beams or used concrete filled steel tubular column to connect with short steel beams to ensure the concrete pouring quality of complex joints.The elastic-plastic time history analysis of structures under large earthquake was carried out,and the results show that the structure is basically in good condition under the large earthquake.