多跨连续刚构桥合龙口顶推力约束优化算法研究

Study on a Jacking Forces Constrained Optimization Algorithm of Multi-span Continuous Rigid Frame Bridges

为实现预应力混凝土多跨连续刚构桥的合理成桥状态,并保证施工过程中的桥梁安全,提出了合龙口顶推力的约束优化算法。以成桥10年时墩顶纵向水平位移平方和达到极小值作为优化目标建立优化方程,利用成桥10年时的主梁跨中挠度及施工阶段的桥墩拉应力和压应力不超限建立约束方程,求解可获得一组最优顶推力。以青海省尕玛羊曲黄河特大桥为例,验证了该算法的可行性和有效性。

In order to realize the reasonable completed bridge state of a RC multi-span continuous rigid frame bridge and ensure the safety during the bridge construction,a constrained optimization algorithm for jacking forces is proposed. The minimum square summation of the horizontal displacements at pier tops in ten years is selected as the optimizing objective and used to establish the optimum equation. Constraint equations are set up based on the reasonable ranges of girder midspan displacements in ten years and pier stresses during construction. Solving the optimum equation and constraint equations gives a set of optimal jacking force. At last,the feasibility and validity of the proposed algorithm are demonstrated through the numerical example of the Gamayangqu bridge over the Yellow River in Qinghai province,China.