矮塔斜拉桥分丝管索塔锚固强弱分区模型及试验研究

Strong-Weak Zone Model and Test of Sleeves in Anchorage Component of Extradosed Cable-stayed Bridge

以王家河特大桥为研究背景,结合现场原位试验,分析了分丝管管径对索塔锚固区各构件的应力情况的影响,提出了分丝管索塔锚固强弱分区模型。通过建立分丝管锚固和交叉锚固有限元模型,对比了两种锚固方式的构件应力情况。结果表明:相同外部条件下采用分丝管锚固时拉索应力仅为交叉锚固的51.4%左右,整体来看,分丝管锚固的应力情况要优于交叉锚固;采用拓扑优化得到了分丝管锚固区的传力路径,提出了分丝管出入口周围混凝土的强弱锚固分区通用优化构型。通用优化区上边长约为0.55倍分丝管外径,混凝土破坏角约为56°,并校核了不利截面的混凝土强度。强弱锚固分区模型可为同类结构设计提供理论参考。

The influence of strand saddle tube's diameter on the stress condition of each member in the pylon anchorage zone was analyzed based on Wangjia River Bridge and field test.A strong-weak zone model of pylon anchorage component with strand-separating saddle was proposed.The finite element models of saddle anchorage and crossing anchorage were established,and the stress of the components of the two anchorages were compared.The results show that the cable stresses of saddle anchorage are nearly 51.4% of those in the cross-anchorage under the same conditions,and the stress conditions of saddle anchorage are better than those of the latter overall.The force transmission paths and optimized geometric configuration of saddle anchorage zone,and the generalized strong-weak zoning model of concrete around the ends of strand-separation tube are obtained by using the topology optimization method.The upside length of the generalized model is approximately equal to 0.55 times outer diameter of strand-separation tube,and the failure angle of concrete is about 56°.Finally,the concrete strength of the critical section are checked.The strong-weak model could provide a theoretical reference to the similar structural design.