拼宽空心板桥荷载横向分布计算方法

为研究拼宽空心板桥荷载横向分布系数的计算方法，首先分别开展采用8，22 cm铺装层的空心板桥足尺模型荷载横向分布试验，接着开展采用刚性拼接结构的拼宽空心板桥足尺模型荷载横向分布试验，并将试验结果与既有铰接板法和刚接板法荷载横向分布系数的计算结果进行对比分析；最后讨论既有铰接板法和刚接板法的适用范围，进而提出了一种新的荷载横向分布系数计算方法，并探讨拼宽空心板桥的拼接结构刚度取值的合理范围。研究结果表明：既有铰接板法和刚接板法分别适用于计算铺装层厚度较小和较大的空心板桥荷载横向分布系数，但二者均无法考虑不同铺装层厚度对荷载横向分布的影响，为此提出了考虑铺装层厚度影响的荷载横向分布系数计算方法，相应的计算结果与试验结果的偏差仅为2.7%；对于采用刚性拼接结构的拼宽空心板桥，铰接板法或者刚接板法均无法正确地反映拼宽空心板桥的荷载横向分布规律，为此提出了考虑拼接结构刚度的拼宽空心板桥荷载横向分布系数计算方法，其中新旧桥板高错位布置的拼宽空心板桥拼接结构刚度为不考虑新桥铺装层厚度的刚度，该方法求得的荷载横向分布规律与试验结果的变化趋势一致，相应的计算结果与试验结果的最大偏差仅为5.4%。

Calculation Method of Load Transverse-distribution for Widening Hollow Slab Bridge

To study the load transverse-distribution calculation method for a widening hollow slab bridge with rigid splicing joint, full-scale model tests were carried out on a hollow-slab bridge with 8 cm and 22 cm pavement and a widening hollow slab bridge with rigid splicing joint. The experimental and calculation results from the existing load transverse-distribution calculation methods that assumed the shear key among the hollow slabs as hinged and rigid joints were comparatively analyzed. The application scope of these existing load transverse-distribution calculation methods with the above-mentioned assumptions was discussed. Then, a new calculation method of load transverse-distribution was put forward. Further, the calculation method of the load transverse-distribution for a widening hollow slab bridge with rigid splicing joint was presented. The results indicate that the existing load transverse-distribution calculation methods that assumed the shear key among the hollow slabs as hinged and rigid joints are applicable for hollow slab bridges with thin and thick pavements, respectively. Both calculation methods could not consider the influence of different pavement thicknesses on the load transverse-distribution. Therefore, a load transverse-distribution calculation method that considers the effect of pavement thickness was proposed. The deviation between the experimental and calculated results using the proposed method was reduced to 2.7%. The load transverse-distribution regularity of a widening hollow slab bridge could not be accurately reflected in the widening hollow slab bridge with rigid splicing joint irrespective if the splicing joint is considered as hinged or rigid joint. Therefore, a calculation method of the load transverse-distribution that considers the splicing-joint stiffness was proposed. The method that uses the stiffness of the splicing joint without considering the pavement thickness of a new bridge in terms of the stiffness of the old and new slabs of a widening hollow slab bridge with unequal-height and rigid splicing joint is proposed. The regularity of the load transverse-distribution obtained from the proposed method is similar to that of the experimental result. Therefore, the calculation precision of the load transverse-distribution can be significantly improved up to a maximum deviation of 5.4%.