混凝土桥梁全寿命设计方法和例证

Whole-life Design Method and Illustration for Concrete Bridges

针对传统桥梁设计方法存在后期维护成本过高、维修资源分配不合理和服役期性能缺乏预见性等不足,提出基于寿命成本和性能的混凝土桥梁全寿命设计方法。建立混凝土桥梁全寿命成本模型作为优化目标函数,并将截面尺寸、混凝土强度和服役期维修时机处理作为设计变量,从结构应力、几何参数和材料参数出发构造约束条件,构建了服役期劣化桥梁性能与维护对策的关系模型,从而验证混凝土桥梁全寿命设计方法优化模型和设计流程。研究结果表明:基于全寿命成本和性能的混凝土桥梁全寿命设计方法合理,能够在设计阶段考虑服役期性能、维护方案及维修成本,平衡初始造价和后期维护成本。

Due to the higher maintenance cost, unreasonable maintenance resources allocation and no prediction in structural performance resulting from conventional bridge design method, the present study developed whole-life design method based on lifetime cost and performance to offset the limitations. Whole-life cost model including construction cost and maintenance cost was established as objective function. The geometrical dimensions, concrete properties and timing of maintenance during service were treated as variables, and structural stresses, geometrical parameters and material properties were treated as boundary conditions to establish a relation model of existing bridges performance and maintenance strategies, so as to verify the reasonability of the developed design method and flowchart. The results indicate that this whole- life design method based on whole-life cost and performace of concrete bridges is reasonable and can consider structural performance, maintenance plan and maintenance cost, and balance the construction cost and maintenance cost.