大庆站房跨层重载桁架稳定承载力研究

STUDY OF THE STABILITY BEARING CAPACITY OF CROSS-LAYER AND HEAVY-LOAD TRUSS STRUCTURE FOR DAQING RAILWAY STATION

大庆西站平面桁架结构跨越两层楼面,结构高度大,承载大,杆件与杆件之间采用刚性连接交织成网状,缺乏有效面外支撑,结构受力非常复杂,存在失稳破坏的风险。为研究大庆西站跨层重载平面桁架的整体稳定性,基于子结构分析法和大位移控制算法对跨层平面桁架结构的非线性稳定承载力进行分析,明确该平面桁架结构的失稳模式和稳定承载力,对结构的整体安全性进行评价。研究表明:跨层桁架的失稳模式表现为半波形面外鼓曲,桁架失稳后表现出"屈曲后不稳定"特性;非线性稳定分析得到的整体稳定系数均大于2,满足规范稳定承载力的要求。

A damage would occur to the plane truss structure of the Daqing West Railway Station due to the lack of effective support outside the plane and the complexity of acting load on the structure , as well as to the huge span crossing two layer floors and the high structure altitude , and also due to the rigid connection nets among the members . In order to study the global stability of the cross-layer plane trusses with larger load of the Daqing West Railway Station, the sub structure analysis method and large displacement control theory were used to analyze nonlinearity stability bearing capacity of the plane structure , which confirmed the buckling mode and stability bearing capacity of the plane truss structure and estimated the safety for the global structure .It was clearly found that the buckling mode of the cross-layer plane truss structure to be a half wave curve outside the plane , which also showed the instability characteristic for the truss after buckling . Obviously , by using nonlinearity stability bearing capacity analysis methods, the global stability coefficient was greater than 2 in all cases, which could meet the requirements for the stability bearing capacity in Chinese design code .