独斜塔斜拉桥索塔交叉锚固区模型试验研究

芙蓉江大桥为主跨170m的地锚式独斜塔斜拉桥,斜拉索交叉锚固于桥塔上塔柱“工”字形截面两侧的锚块上。为了解该桥索塔锚固区的应力分布,选取塔顶5对斜拉索的锚固区段为对象,设计制作1∶4的缩尺模型进行静载试验,并采用MIDAS FEA软件建立索塔锚固区有限元模型,分析锚固区塔壁和锚块的应力分布。结果表明:在斜拉索索力及恒载作用下,桥塔地锚箱侧塔壁处于受压状态,主跨侧塔壁处于受拉状态,塔壁最大压应力为4.2 MPa,最大拉应力为1.68MPa,均出现在工字形翼缘;斜拉索索力使锚块处于竖向受压、横向受拉的复杂应力状态;实桥桥塔应力的实测值与试验模型实测值和理论值均吻合较好。

Model Test Study on Crossing Cable Anchorage Zone for Single-Oblique-Pylon Cable-Stayed Bridge

Furongjiang River Bridge is a ground-anchored single-oblique-pylon cable-stayed bridge with a main span of 170 m, and the stay cables are cross-anchored in the anchorage block on both sides of the I-shaped solid section of the upper pylon column. In order to analyze the stress distribution of the anchorage zone of the pylon, we selected the section on the pylon top anchoring 5 pairs of stay cables, and built a 1∶4 scale model to perform static load tests. Meanwhile, we established a finite element model of the anchorage zone by using the MIDAS FEA software to analyze the stress distributions of the anchorage zone on the pylon wall and anchorage block.The results show that, under the action of cable force and dead load, the pylon wall of the anchorage box side of the bridge pylon is in a state of compression, and the pylon wall of the main span side is in a state of tension;the maximum compressive stress of the pylon wall is 4.2 MPa, the maximum tensile stress is 1.68 MPa, and both stresses appear in the I-shaped flange;the cable force causes the anchorage block to be in a complex stress state of vertical compression and lateral tension. The measured stress values of the bridge pylon are in good agreement with the measured values of the test model and theoretical values.