预制节段桥梁钢榫键接缝受力特性

Mechanical Characteristics of Steel Keyed Joints of Precast Segmental Bridge

摘要:

设计2个接缝直剪试验，并结合数值分析对钢榫键接缝在施工阶段和成桥阶段的受力特性进行分析。结果表明：在侧限压力的作用下钢榫键接缝依靠钢材和混凝土的接触受压来传递接缝间的剪力，接缝具有较高的抗剪承载力和良好的延性，当荷载?位移曲线进入水平段后，接缝仍能承受较大的相对变形，并保持承载力不降低；在施工阶段应由钢榫键跨缝齿的非弹性变形对临时荷载进行控制设计，在成桥阶段应由钢榫键材料剪切强度对接缝直剪强度进行控制设计；钢榫键接缝直剪抗力可按剪切实用公式计算，钢榫键材料和跨缝齿直径均是影响钢榫键接缝承载力的关键因素。

Abstract:

Two direct shear experiments were designed， and the mechanical characteristics of steel keyed joints in the construction and service stage were analyzed with a combination of numerical analysis. It is shown that the joints depend on the contact compression between steel and concrete to transfer the shear force between the joints under the action of confining stress. The joints have high shear bearing capacity and good ductility. When the load-displacement curve enters the horizontal section， the joints can still bear large relative deformation， and its bearing capacity does not decrease. In the construction stage， the inelastic deformation of crossing-joint teeth should be used to control the temporary load design. In the service stage， the direct shear strength of the joints should be controlled by the shear strength of steel key’s material. The direct shear resistance of steel keyed joints can be calculated according to the shear formula. The material of the keys and the diameter of the crossing-joint teeth are the key factors affecting the bearing capacity of the joints.