采用横向预应力的装配式空心板桥受力性能与设计计算方法

为了提高铰缝结合面的开裂荷载和破坏荷载，解决空心板桥横桥向受力问题，研究了采用横向预应力的装配式空心板桥的受力性能，采用局部模型试验的方法分析了铰缝结合面受力机理，采用足尺模型试验的方法研究了空心板桥整体受力性能，并基于铰缝结合面受力机理，确定了横向预应力的上、下限，进而提出了横向预应力设计计算公式。试验结果表明:采用横向预应力结合面的法向和切向黏结强度分别为1.40~1.45和0.50~0.62 MPa，较未采用横向预应力分别提高了8.1%~12.5%和12.4%~38.3%，而且提高横向预应力可以提高结合面的法向和切向黏结强度；采用横向预应力的空心板桥足尺试验模型的破坏模式表现为空心板的开裂破坏，试验过程中未出现铰缝开裂现象；横向预应力的施加可以提高空心板之间的横桥向联系，避免结构由于铰缝结合面损伤而丧失横向传递荷载的能力并导致结构破坏，提高空心板桥的极限荷载；提出的横向预应力设计计算公式可以较好地计算空心板桥横向预应力的设计值。 

Mechanical performance and design calculation method of prefabricated voided slab bridge with transverse post-tensioning

In order to improve the crack load and failure load of the hinge joint junction surface and solve the problem of the transverse force of the voided slab bridge, the mechanical performance of the prefabricated voided slab bridge with transverse post-tensioning (TPT)was studied. The mechanical mechanism of the hinge joint junction surface was analyzed by a local model test. The full-scale model test was adopted to research the overall mechanical performance of the voided slab bridge. Based on the mechanical mechanism of the hinge joint junction surface, the upper and lower limits of TPT were determined, and the design calculation formula of TPT was put forward. Test results show that the normal and tangential bonding strengths of the junction surface with TPT are 1.40-1.45 and 0.50-0.62 MPa, respectively, which are 8.1%-12.5% and 12.4%-38.3% higher than those without TPT, respectively. Moreover, increasing TPT can improve the normal and tangential bonding strengths of the junction surface. The failure mode of the full-scale test model of the voided slab bridge with TPT is the cracking failure of the voided slab, and no hinge joint cracking occurs during the test. The application of TPT can improve the transverse connection among slabs, avoid the loss of the transverse load transmitting ability due to the hinge joint junction surface damage and the failure of the structure, and increase the ultimate load of the voided slab bridge. The proposed formula for TPT design can effectively calculate the design value of TPT of the voided slab bridge.