基于刘家峡钢管混凝土桥塔的推出试验研究

Study of Push-out Test Based on CFST Pylon of LiuJiaxia Bridge

刘家峡悬索大桥是目前国内最大的钢-混结构桥塔。对于这种新型结构而言,钢管和混凝土之间的相互作用效应是其受力复杂性和安全可靠性所在。通过对刘家峡悬索桥钢-混桥塔缩尺模型进行推出试验,得出钢-混界面极限粘结强度与粘结破坏时的滑移距离,进而与ANSYS建立的非线性有限元仿真结果进行对比,证实了采用有限元仿真能够有效模拟钢管混凝土结构。利用该有限元模型研究焊钉对钢-混结构粘结滑移的影响,结果显示:焊钉对钢管与混凝土之间的初始粘结状态影响甚微,但初始粘结破坏后,能显著减小钢管与混凝土之间的滑动距离。这对钢管混凝土工程的设计和施工具有一定的借鉴意义。

Liujiaxia suspension bridge adopts tower of Concrete-Filled Steel Tube structure,which is the first time in domestic. Interaction effect between concrete and steel has its mechanical complexity and safety to the new structure,A scale model of original Liujiaxia suspension bridge pylon is constructed for Push-out test,the bonding failure strength and slip displacement obtained by test,Compare the bond failure load and displacement of bond failure acquired through the segment model test of CFST tower with ANSYS calculation results,which confirms that in the practical engineering,the finite element result can be effectively used,at the same time,it is rather safer. Then welding are studied by using the finite element model of CFST of bond-slip effect,the result shows: the CFST structure of the welding can not increase the initial bond strength between steel and concrete,but reduce the sliding displacement between steel and concrete.It is helpful for engineering and constructing CFST structure.