城市轨道交通矩形地下结构层间位移角研究

Research on Story Drift Angle of Urban Mass Transit Rectangular Underground Structures

城市轨道交通矩形地下结构抗震设计时,除了强度验算外,还需要变形验算。矩形地下结构在横截面一般可简化为矩形框架,可以使用层间位移角作为变形控制指标。参考地面建筑框架结构层间位移角的已有成果,通过分析地面建筑和地下建筑的异同,并统计了国内46组钢管混凝土框架和145组型钢混凝土框架的层间位移角的试验数据,结合城市轨道交通结构的特点和我国的国情,得出了城市轨道交通矩形地下结构的层间位移角的不同性能要求下的限值:小震、中震、大震下的限值分别为1/550、1/250、1/70。

Both strength checking and deformation checking are necessary to seismic design of urban mass transit rectangular underground structures. Rectangular underground structures could in general be simplified as rectangular framework,then the story drift angle is selected as formation index. Performance index values of urban mass transit rectangular underground structure story drift angle are put forward by reference to modified performance index values of ground structure story drift angle,which was based on a statistical analysis for experiment data of forty-six groups concrete-filled steel tubular frames and one hundred forty-five groups steel-reinforced concrete frames and took into account similarities and differences between surface structures and underground structures. It is found in the study that taking into account characteristic of urban mass transit structures and the situation in China,limiting values of different performance levels are as follows: 1 /550,1 /250 and 1 /70 in case of frequent earthquake, design earthquake and rare occurrence earthquake respectively.