摘要
拉萨市纳金大桥主桥为跨径(70+117+117+70)m的三塔矮塔斜拉桥。为对该桥小半径(分丝管半径为2.5m)大索力(斜拉索在索鞍段的最大径向均布荷载为2 372kN/m)鞍座所在桥塔节段的性能进行研究,采用ANSYS建立1/4桥塔节段有限元模型进行应力分析,并制作该部分桥塔足尺模型进行试验,测试结构应力、斜拉索与索鞍之间的摩阻力、锚固装置内的环氧砂浆对斜拉索的握裹力。研究结果表明:该桥桥塔采用小半径分丝管是安全可靠的,索鞍的摩阻力和抗滑力均满足使用要求。通过对有限元分析和试验的总结,提出严格控制转向鞍的加工及定位精度、保证混凝土浇注的密实性、主梁施工时保证两侧对称同步施工等建议。
The main bridge of the Najin Bridge in Lhasa City is a three-pylon extradosed ca- ble-stayed bridge with span arrangement of （70＋117＋117＋70） m. To study the mechanical be- havior of the pylon segment where the saddle with small radius （the radius of the deviator is 2.5 m） and great cable force （the maximum uniform radial load of the stay cable at the pylon segment with saddle is 2 372 kN/m）was installed, the software ANSYS was used to set up the finite ele- ment model of a 1/4 pylon segment to do stress analysis, and the full-scale model test was also designed for the 1/4 pylon segment to test the structural stress, the frictional resistance between the stay cables and the saddle, the grip between the epoxy grouting and the stay cable inside the anchoring device. The results of the study demonstrate that the deviator with small radius installed in the pylon is safe and reliable and both the frictional resistance and the slippage resist- ance of the saddle meet the service requirement. It is suggested based on the summary of the finite element analysis and the full-scale model test that the fabrication and positioning precision of the deviator should be strictly controlled, and measures should be taken to ensure the casting compactness of the concrete and the symmetrical synchronous construction for the main girder.
出处
《世界桥梁》
北大核心
2012年第5期63-68,共6页
World Bridges
关键词
矮塔斜拉桥
桥塔
鞍座
分丝管
模型试验
有限元法
extradosed cable-stayed bridge
pylon
saddle
deviator
model test
finite element method
