三角刚架斜腿约束作用及影响系数实用计算方法  

Inclined Leg Restriction for Triangle Rigid Frame and Practical Calculation Method of Influence Coefficient

作　　者：刘来君[1] 杨雨厚[1,2] 陈永瑞[1] 郝天之 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]广西交通科学研究院,广西南宁530007

出　　处：《中国公路学报》2015年第4期44-51,共8页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51408040);云南省交通运输厅科技计划项目(云交科2013(A)02)

摘　　要：为研究三角刚架斜腿对系梁预应力约束作用的量化影响,通过揭示其作用全过程,引入基本假设,基于混合法推导出对称三角刚架斜腿约束作用影响系数的计算公式,通过拆合过程,进一步提出了非对称三角刚架的影响系数实用计算方法,并进行了工程实例验证分析。研究结果表明:斜腿约束作用为三角刚架固有特性,其影响系数仅与截面尺寸、材料、几何形状有关;约束作用影响系数的公式计算结果与有限元分析结果及模型试验结果相对误差在5%以内,可满足工程精度要求;消除斜腿约束作用不利影响的最优解决方案是在设计中提高系梁预应力的张拉控制力,若设计时未考虑,也可在施工中采取分段浇筑系梁混凝土或在斜腿中预留后浇带的方法解决。In order to quantify the impact of inclined leg of triangle rigid frame on the prestressing force restriction of tie-beam, mechanism of action during the whole process was revealed firstly. Based on some basic assumptions, calculation formulas of influence coefficient for inclined leg restriction for symmetrical triangle rigid frame were put forward with hybrid method. Then through the process of separation and mergence, a practical calculation method of influence coefficient for asymmetrical triangle rigid frame was put forward as well. Finally, engineering examples were taken to verify the analysis. The results show that inclined leg restriction is the inherent characteristic of triangle rigid frame, whose influence coefficient is only related to the cross-sectional dimension, material and geometric feature of a triangle rigid frame. The relative error between calculating result of influence coefficient and finite element simulated result and model test result is within 5%, satisfying the request of engineering. To eliminate the negative influence of inclined leg restriction, the optimal solution is to improve the prestressing force of tie-beam during the design. If not considered in design, it can take the solution of pouring tie- beam concrete segmentally or setting the post-pouring strip aside in inclined leg during the construction stage.

关 键 词：桥梁工程 三角刚架 混合法 斜腿约束作用 影响系数 实用计算方法 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]