斜拉桥混合塔结合部受力机理模型试验

为揭示斜拉桥混合塔钢-混凝土结合部传力机理,对某斜拉桥桥塔钢-混凝土结合部进行1∶3缩尺模型试验,测试结合部的应变分布及钢-混凝土间的相对滑移.结合试验模型建立空间有限元模型,进一步探讨该类型连接件的受力特点及各结构参数对连接件受力的影响.研究结果表明:各构件应力水平较低,钢与混凝土之间相对滑移较小,二者协同作用较好;承压板和连接件是主要的传力构件,分别承担了约40%和60%的荷载;距承压板0.6倍结合部长度内连接件竖向剪力较小,0.6~1.0倍结合部长度内连接件竖向剪力逐渐增大;结合部长度、连接件间距对连接件剪力影响较大,开孔板孔径和承压板厚度对连接件剪力影响较小.

Model test of composite joint for tower of cable-stayed bridge

In order to investigate the load transfer mechanism of composite joint for tower of cable-stayed bridge, a segment model test with a scale of 1:3 was carried out, and the strain distribution of composite joint and the relative slippage between steel and concrete structure were obtained. A three-dimensional finite element model was established based on the test model, the structural performance of shear connectors and the effects of main parameters of composite were further investigated. The analysis results show that the stress components are at a lower level. There is a small relative slippage between steel and concrete, and both of them can bear the force collaboratively. The bearing-plate and shear connectors are main load transfer components, and could share 40% and 60% of the load respectively. Vertical shear force is at a lower level within 0.6 times length of composite joint of bearing-plate, while the vertical shear force increases gradually within 0.6-1.0 times length. The length of composite joint and the distance of shear connector have a great influence on the shear force of connector, while the diameter of the hole and the thickness of bearing-plate display a less effect.