自锚式悬索桥主缆锚固区空间应力分析

目的对典型的锚固区局部节段进行分析，以解决自锚式悬索桥主缆锚固区结构复杂，平面杆系程序无法把握锚固区复杂受力状态的问题，为桥梁设计和施工提供参考依据．方法运用MIDAS／FEA建立浑河景观桥锚固区局部有限元模型，分析最不利索力设计值下的局部应力状态及不同荷载下的极限承载力．结果锚固区在主缆索力T=50000kN作用下，产生的最大位移为4．91mm；锚垫板的索孔周围的von Mises应力在110MPa左右．随着荷载的增加，锚固区von Mises应力不断增大．当索力为设计荷载的3．5倍时，锚固区各板件的应力均达到了468MPa以上，位移最大值为24mm．结论主缆锚固区各构件的刚度和强度均满足要求，锚固区的极限承载力为设计荷载的3．5倍，结构的安全系数较高．

Analysis of Spatial Stress in Main Cable Anchorage Zone of the Self-Anchored Bridge

In order to solve complex stress state problem in the anchorage zone of self-anchored bridge which could not be grasped with the conventional plane linkage program and to provide a basis for construction and design of bridges, a finite element model of Hunhe landscape bridge was built using MIDAS/FEA and the local stress state was analyzed by the most unfavorable cable loading and the ultimate bearing capacity under different loads subjected in the anchorage zones was calculated. Results show that the maximum displacement of anchorage zone is 4. 92 mm under main cable force T = 50 000 kN and von Mises stress around the cable hole of anchor plate is about 110 MPa. With the load increasing, the Von Mises stress of anchorage zone increases constantly. If the load is increased to 3.58 times of the design value, the stresses of all parts in the anchorage zone are higher than 468 MPa and the maximum displacement is 24 mm. It indicates that the stiffness and strength of all parts in the main cable anchorage zone meet the requirements. It is also observed that the ultimate bearing capacity of anchorage zone is 3.5 times of the design load value, and the safety factor of structure is relatively high.