水泥混凝土路面传力杆应力分析力学模型

Mechanics Analysis Model of Dowel Bar in Concrete Pavement

摘要:

应用三维有限元模型分析水泥混凝土路面中传力杆与水泥混凝土的接触状况,并基于弯曲刚度等效原则将传力杆和水泥混凝土面层系统简化为双层梁结构。计算结果表明,弹性地基上双层梁结构可很好地描述水泥混凝土路面的挠曲效应,而接缝处的双层梁相对位移、转角、以及挤压应力合力与三维有限元解的差异,只需对双层梁层间竖向反应模量进行修正即可；随后,总结归纳了相对位移、转角及挤压应力合力修正系数的回归式,讨论给出了接缝传力杆的抗剪刚度与抗弯刚度的计算式,并指出传力杆的传递弯矩的能力很小可忽略；最后,计算分析了梁端部作用集中荷载时,有基层的地基梁接缝传荷问题,指出在接缝抗剪刚度相同条件下,基层存在可使接缝两侧挠度比增大,接缝传递的剪力减小。

Abstract:

3D finite element model was used to analyze the contact state between dowel bar and cement concrete pavement. Based on the equivalent principle of bending stiffness, the dowel bar and concrete surface layer system were simplified to double-layer beam structure. The calculation results show that the double-layer beam structure on elastic foundation can describe the deflection effect of concrete pavement well. In addition the relative displacement, rotation angle and the stress of the double-layer beam are different from the 3D finite element solution, which can be eliminated by modifying the vertical reaction modulus between the double-layer beams. Furthermore, the regression formulas of the relative displacement, rotation angle and the resultant force of extrusion stress were summarized. The formulas of the shear stiffness and bending stiffness of the dowel bar joint were given, and it was pointed out that the ability of the dowel bar to transfer bending moment was negligible. Finally, the load transfer problem of double-layer beam joints under the concentrated loads at the beam end was calculated and analyzed, which shows that the existence of base can increase the joint deflection ratio and reduce the shear force transmitted by the joint, when the joint shear stiffness is constant.