波形钢腹板PC组合箱梁桥的挠度计算与分析

为研究箱梁剪力滞效应和钢腹板剪切变形对波形钢腹板PC箱梁桥挠度的影响，基于能量变分法对该桥型的挠度计算进行了分析.首先，从箱梁翼板的面内剪切变形和弯曲剪力流的分布规律出发，在理论上推得可同时考虑箱梁剪力滞效应和钢腹板剪切变形的纵向位移函数；其次，以所得的纵向位移函数为基础，运用能量法推导出该桥型的挠度计算公式，并用模型试验及有限元法对公式的正确性进行了验证；最后，分析在箱梁宽跨比和钢腹板高度变化时，在不同荷载类型作用下，箱梁剪力滞效应和腹板剪切变形分别对波形钢腹板PC简支和连续箱梁桥挠度的影响.研究结果表明:当宽跨比为0.108~0.650时，在集中荷载作用下，剪力滞效应和钢腹板剪切变形对波形钢腹板PC连续箱梁桥的挠度影响较大，不可忽略；当宽跨比为0.108~0.650时，在均布荷载作用下，波形钢腹板PC简支和连续箱梁桥仅需考虑波形钢腹板剪切变形对其挠度的影响，只有在特定的宽跨比和特定的波形钢腹板截面高度下，才需要考虑剪力滞效应对其挠度的影响. 

Deflection Calculation and Analysis of PC Box Girder Bridges with Corrugated Steel Webs

In order to study the effects of shear lag and shear deformation caused by corrugated steel webs on the deflections of prestressed concrete (PC) box girder bridges with corrugated steel webs (CSWs), the deflection calculation for this type of bridge was calculated based on the energy variational method. First, based on the in-plane shear deformation of the flange plates and the distribution law of flexural shear flow, the longitudinal displacement function for this type of bridge was derived. This function can be used to estimate the shear lag effect and the shear deformation of CSWs. Second, based on the obtained longitudinal displacement function, the deflection formulas for a box girder bridge with CSWs were obtained using the variational principle method. The effectiveness of the formulas was verified using model tests and the ANSYS finite element analysis. Finally, variations in the width-span ratio and the heights of CSWs were made, under different types of loads, to study their influences on shear lag and shear deformation, and thereby on the deflections of simply supported and continuous box girder bridges with CSWs. The results show that when the width-span ratio is 0.108-0.650, the shear lag and the shear deformation of CSWs have significant effects on the deflection of continuous box girder bridges with CSWs, when under a concentrated load, which cannot be ignored. When the width-span ratio is 0.108-0.650, the effects of shear deformation of CSWs on the deflection of simply supported and continuous box girder bridges with CSWs, should only be considered under uniform load, while the effect of the shear lag should only be considered under specific span-width ratios and specific heights of CSWs.