连续梁桥高墩计算长度研究

Study on Effective Length of Continuous Girder Bridge with High piers

桥墩计算长度是高墩连续梁桥桥墩设计的一个重要参数。首先比较分析了各国规范对于标准约束条件下桥墩计算长度系数的规定;然后根据最小势能原理,考虑墩底约束刚度、墩顶约束刚度的影响,推导了桥墩计算长度系数的计算公式;最后详细讨论了约束刚度取值对桥墩计算长度系数的影响。研究结论表明墩底约束刚度、墩顶转动刚度对桥墩计算长度系数影响较小;桥墩计算长度系数随着墩顶水平刚度增加而迅速减小,而后趋于稳定。研究结论为高墩设计提供了重要参考。

High-pier length is an important parameter in the design of continuous girder bridge with high piers.Firstly, this paper analyzed the standard calaulation methods used for length of pier's in the world. Then it deducedthe calculation formulas of effective length factor on the basis of the principle of minimum potential energy,andthe effects of restraining stiffness from bottom and top of high-pier into account.Finally,it discussed the impact ofrestraining stiffness values on pier effective length factor in detail. The results show that restraint stiffness of pierbottom and rotational stiffness of pier top have little impact on pier effective length factor. But the factor decreasesrapidly when the horizontal stiffness of pier top increases. When the horizontal stiffness exceeds a certain value,the factor becomes stable. All in all, the research conclusion provides important reference for high-pier design.