连续刚构桥高温合拢顶推力的计算方法研究

Algorithms for the Jacking Force of High-temperature Closure Of a Continuous Rigid-frame Bridge

连续刚构桥实际合拢温度高于设计合拢温度时,合拢温差将使墩顶产生水平位移,导致结构产生温度附加内力,可通过施加水平顶推力来消除合拢温差的不利影响.提出了两种关于顶推力的计算方法:1)消除墩顶水平位移法;2)消除主梁拉力法.以龙潭河特大桥为工程实例,按上述两种方法分别计算了高温合拢时的水平顶推力,通过分析比较,两者的计算结果基本一致.表明两种计算方法均可行,并且消除主梁拉力法更为简单快捷.

When the actual closure temperature of a continuous rigid-frame bridge is higher than the designed temperature, the difference will cause a horizontal displacement at pier top and make its structure suffer a temperature-attaching inner force. A horizontal jacking force can be exerted to eliminate the adverse effects caused by such difference. Two algorithms for the jacking force are proposed in this paper： one is to eliminate the horizontal displacement at pier top and the other is to eliminate the tensile force in its main girder. Taking Longtan River Bridge as a practice example, the paper calculates the horizontal jacking force of its hightemperature closure according to the above algorithms. An analysis and a comparison prove that results from both calculations are basically consistent. This shows that the two algorithms are feasible, and their way to eliminate the tensile force is simpler and quicker. Key words：