自适应空间缆鞍座性能分析

Performance Analysis of Self-Adaptive Spatial Cable Saddle

针对传统鞍座在悬索桥施工过程中无法保证主缆从施工前的竖直状态转换到施工后的空间缆状态而发生自适应运动的情况,设计了一种自适应空间缆鞍座。该鞍座由主索鞍、限位板和转向机构3部分组成,转向机构能够在承受主缆载荷作用下顺利实现索鞍的自适应转动,并在成桥后利用螺栓固定从而保证悬索桥的安全性。以阳宝山特大桥为背景,采用有限元与试验结合的方式研究所提出的自适应空间缆鞍座的运动情况。结果表明:悬索桥缆索施工时,自适应空间缆鞍座能随着加载过程发生自适应运动;鞍座的最大应力为165.8 MPa,中心最大竖向转角为0.7°,端部横桥向最大位移为6.657 mm;有限元计算结果与试验结果较为接近,但鞍座运动过程有明显区别,试验中运动过程变化很不规则,没有明显的规律,鞍座中心竖向转角和端部横桥向位移均发生突变,有限元分析运动过程变化平缓;卸载后,自适应空间缆鞍座能自复位且没有残余变形。

In the suspension bridge construction,the main cable supported on conventional saddle is not supposed to do self-adaptive motion to realize condition transformation,namely transforming from the vertical state before construction to spatial state after completion.To address this issue,a type of self-adaptive spatial cable saddle,which consists of the main saddle,limiter plates and steering apparatus,is developed.The steering apparatus allows the smooth self-adaptive motion of the saddle while carrying the main cable loads,and is able to be fixed by bolts after completion of the bridge,such that the safety of the suspension bridge is ensured.The application of the proposed saddle is illustrated by the case study of the Yangbaoshan Bridge.The motion of saddles of the example bridge was numerically simulated and examined by tests.It is shown that the spatial cable saddle can perform adaptive motion to suit the loading condition.with maximum stress,maximum center rotation angle and maximum transverse displacement at saddle ends being 165.8 MPa,0.7°and 6.657 mm,respectively.The finite element calculations approximate the test results,but with different saddle moving processes.The moving process in the tests is not regular and shows no evident rule,and the vertical rotation angle at the saddle center and the transverse displacement at the saddle ends show abrupt fluctuations,but those fluctuations in the finite element analysis are flat.After deloading,the self-adaptive spatial cable saddle is able to recenter itself,and no residual deformation occurs.