基于裂缝控制的连续刚构桥合理合龙顶推力

Reasonable Closure Jacking-force of Continuous Rigid Frame Bridge Based on Crack Control

为防止顶推力过大导致结构开裂,基于顶推过程中和正常使用时顶推力和墩底裂缝的关系,以墩底混凝土裂缝宽度不超限为控制条件确定顶推力的上下限值为约束条件,将合理顶推力的求解问题转化为线性规划问题,得出顶推力求解公式。通过沮河大桥实例验证,顶推力计算方法可保证顶推力的作用,且顶推力不会使墩底裂缝宽度超限。

In order to prevent structure crack caused by excessive jacking force,based on the relationship between jacking force and cracks at pier bottom during jacking process and normal operation,taking the crack width of concrete at pier bottom not exceeding the limit as the control condition and the upper and lower limit values of jacking force not exceeding the limit as the constraint condition,the problem of solving reasonable jacking force was then transformed into a linear programming problem,and the solution formula for jacking force was then obtained.Through the example verification of the Juhe Bridge,it can be concluded that the calculation method of jacking force can ensure the effect of jacking force and it will not make the crack width of the pier bottom exceed the limit.