斜拉桥桥塔多采用 A 型或倒 Y 型的结构形式，其索塔锚固区域处于复杂空间受力状态，普通钢筋混凝土结构已经难以满足受力要求。结合某斜拉桥索塔锚固区的混凝土拉应力超限的现象，进行合理预应力配束。建立三维 ANSYS 有限元实体模型，对施加预应力后的索塔锚固区进行局部应力分析。分析表明：合理施加预应力可以有效改善索塔锚固区的受力性能，克服了普通钢筋混凝土结构拉应力超限的问题，且预应力钢束布置并不引起桥塔的附加位移。%Type A or inverted type Y are widely adopted in the bridge towers of cable-stayed bridges ,and the cable-tower anchorage zones are under complex spatial stress .Based on a cable-stayed bridge whose concrete tension stress in its ca-ble-tower anchorage zone is beyond the limits ,the pre-stressed steel bars were reinforced rationally .Then ,the finite ele-ment model is established by using ANSYS so as to analyze the local stress state of the cable-tower anchorage zone after prestressing .The results indicate that the reasonable layout of the pre-stressed steel in cable-tower zone could effectively improve the local mechanical behavior ,and overcome the phenomenon that the concrete tension stress is beyond the lim-its .Moreover ,the layout of the pre-stressed steel would not cause the additional displacement of the bridge pylon .
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