承压锚固型斜拉桥钢塔结合段受力性能和锚杆传力机理研究

承压锚固型结合段锚固构造为斜拉桥钢索塔重要传力构件,研究了承压锚固型结合段的承压、抗弯性能,分析了施工阶段分两次张拉过程中及成桥运营期间各部件的受力,揭示了预应力锚固螺杆的应力分布状况与传力机理,掌握各部件实际应力分布并验证设计的安全性,为设计、施工和监测提供可靠依据.研究结果表明：索塔钢混结合段锚固构造在两次张拉及运营期间下受力明确,构造合理,承压、抗弯性能良好;预应力锚杆为重要传力构件,其有效预应力是影响压浆层与承压板之间可靠结合的关键因素,在锚杆预应力损失50%时,顺桥向弯矩最不利工况下承压板与压浆层之间约1/3区域脱离接触,应对运营期间的锚固螺杆中的有效预应力进行长期监测,并制定相应的补张方案.

Research on Mechanical Behavior of Bearing Anchorage Combination Segment and Transfer Mechanism of Anchor Rod in Steel Tower of Cable-stayed Bridge

Bearing anchorage combination segment is a key force transmission component in steel tower of cable-stayed bridge.In order to acquire the actual stress distribution of each component and verify the design safety,research has carried on analyzing the force state of each component during two tension stage of construction phase and the finished bridge state and studying the bearing and flexural performance of combination segment.Therefore,stress distribution and transfer mechanism of prestressed anchor rod is demonstrated so as to provide a reliable basis for the design,construction and monitoring.Results have shown：the bearing anchorage combination segment of steel tower has a clear force state and reasonable figuration,shown a fine bearing and bending performance.The prestressed anchor rod plays a significance role on the combination between bearing plate and grouting layer and about 1/3area between them will be disengagement if the prestress loses 50% under unfavorable conditions of the bending moment along the bridge.It is important to have a long-term monitoring of prestress in the rod and develop an appropriate solution of complement tension.