多梁式波形钢腹板工字钢组合梁荷载横向分布系数研究

为探讨多梁式波形钢腹板工字钢组合梁横向分布系数计算方法,同时考虑波形钢腹板抗扭刚度、剪切变形及钢混滑移效应,对传统的偏心压力法、修正偏心压力法及刚接梁法进行修正,并结合有限元模型通过一座典型的4主梁波形钢腹板工字钢组合梁桥对比分析了上述方法的适用性,最后基于参数分析研究了横隔板数量及刚度对其横向荷载分布系数的影响。结果表明,考虑剪切变形及滑移效应的刚接梁法得到的荷载横向分布系数与有限元值符合最好;当桥梁宽跨比小于2时,宜采用刚接梁法计算各主梁荷载横向分布系数,当宽跨比大于2时,宜采用更为简洁的修正偏心压力法进行计算;横隔板的设置可改善各主梁荷载横向均匀分布,但跨间横隔板间距和刚度对其荷载横向分布系数影响较小,实桥设计时可仅在端部及跨中位置布置横隔板,横隔板刚度及其余部位横隔板数量可根据结构稳定性要求进行布置。

Study on the load transverse distribution coefficient of multi-beam composite I-beam with corrugated steel webs

In order to explore the calculation method of the load transverse losd distribution coefficient of a multi-beam composite I-beam with corrugated steel web,the traditional eccentric pressure method,modified eccentric pressure method and rigid-connected beam method are modified by considering the torsional stiffness,shear deformation and steel-mixed slip effect of the corrugated steel webs.Combined with the finite element model,the applicability of the above methods are compared and analyzed through a typical composite four-beam bridge with corrugated steel webs.Then,the influence of the number and stiffness of the diaphragm on its transverse load distribution coefficient is studied based on the parametric analysis.The results show that the transverse load distribution coefficient obtained by the rigid-connected beam method considering shear deformation and slip effect is in the best agreement with the finite element value.When the width-span ratio of the bridge is less than 2,the rigid-connected beam method should be used to calculate the transverse load distribution coefficient of each main beam,when the width-span ratio is greater than 2,the more concise modified eccentric pressure method should be used for calculation.The installation of diaphragms can improve the transverse load uniform distribution of each main beam,but the spacing and stiffness of the diaphragms between spans have little effect on the transverse load distribution coefficient.In the design of a real bridge,the diaphragms can be arranged at the end and mid-span positions,and the rigidity of the diaphragms and the number of diaphragms in the remaining parts can be arranged according to the requirements of structural stability.