无内腹板式钢索塔锚固区的力学性能分析

Analysis of mechanical properties of anchorage zone of steel cable tower without internal web plate

为了适应空间曲线塔柱的造型与受力,空间错位布设的拉索锚梁需要舍弃内腹板,增加自身长度直接焊接于索塔壁板。由于缺失了内腹板的对拉锚固作用,使得无内腹板式钢索塔锚固区的传力机理、承载能力具有明显特殊性。通过数值模拟方法对无内腹板式索塔锚固区进行弹塑性全过程分析,并用模型试验数据进行对比验证,研究无内腹板式索塔锚固区的力学性能并进行优化设计。结果表明,不设内腹板明显降低了拉索锚梁的刚度,无内腹板式拉索锚梁结构的极限承载力为11 130 kN,达2.8倍设计荷载,安全储备充裕,且未出现扭转现象。索力主要由拉索锚梁的支承板N1进行传递,支承板N1与索塔壁板间的焊缝是关键传力部位,可实现71%的索力传递,但此处易出现应力集中现象。增加边跨侧拉索锚梁B17支承板N1的厚度可改善结构的受力性能,有效减少应力集中。

In order to adapt to the shape and stress of the spatial curved tower column,the cable anchor beam arranged in a staggered manner in space needed to abandon the inner web and increase its length to be directly welded to the wall plate of the cable tower.Because of the lack of the tension anchoring effect of the inner web,the force transmission mechanism and bearing capacity of the anchorage zone of the cable tower without inner web were obviously special.Through the numerical simulation method,the elastic-plastic whole process analysis of the anchorage zone of this kind of cable tower was carried out,and the model test data was used for comparison and verification.The mechanical properties of the anchorage zone of the cable tower without inner web plate were studied and optimized.The results showed that the absence of an inner web significantly reduced the stiffness of the cable anchor beam;The ultimate bearing capacity of the non inner web type cable anchor beam structure was 11130 kN,reaching 2.8 times the design load,with sufficient safety reserves and no torsion phenomenon;The cable force was mainly transmitted by the support plate N1 of the cable anchor beam.The weld between the support plate N1 and the cable tower wall plate was the key force transmission part,which could achieve 71%cable force transmission,but stress concentration was prone to occur here;Increasing the thickness of the B17 support plate Nl of the side span anchor beam could prove the structural stress performance and effectively reduce stress concentration.