青藏交直流联网工程预制混凝土装配式杆塔基础上拔与水平力组合荷载试验

Prefabricated Concrete Assembly Foundation for Pole Tower in Qinghai-Tibet AC/DC Grid Interconnection Project

通过监测上拔水平力组合作用下基础构件位移及连接件应力变化,研究了青藏交直流联网工程混凝土预制装配式基础的基础承载变形特性、基础构件协同工作性能以及构件连接件承载应力水平。结果表明:上拔和水平组合荷载作用下,混凝土预制装配式基础具有协同工作性能,混凝土预制装配式基础拼装间隙、拼装过程中螺帽拧紧程度不同以及基础预制加工误差是预制装配式基础共同工作性能的主要影响因素。水平荷载和基础拼装缝隙对基础上拔和水平位移有影响,基础荷载-位移曲线为缓变型。基础底板连接件整体上承受拉应力作用,在极限荷载范围内,均呈弹性应力状态。

The prefabricated concrete assembly foundation for Qinghai-Tibet AC/DC grid interconnection project was tested under uplift combined with lateral load. The mechanical co- working properties for the different parts of the foundation were analyzed based on the monitoring results of the load-displacement behavior and the structural stress. The test results indicated that the different connected parts of the prefabricated concrete assembly foundation worked in a coordinated way to bear the uplift and lateral loads. The structural characteristics of the assembly foundation, the gaps among the assembly parts, the discrepancy of the nut screwing up and the mismatching tolerance during consolidating are the key factors to determine the performance of the foundation. The lateral load and the gaps among the assembly parts affect the displacement of foundation. Under the estimated ultimate uplift load, the stresses of the connecting parts are in a state of elastic stress .