基于改进粒子群优化算法的UHPC简支梁桥优化设计

Optimization design of simply supported UHPC beam bridges based on improved particle swarm optimization algorithm

为了充分利用超高性能混凝土(ultra high performance concrete, UHPC)优越的力学性能,降低桥梁造价,采用粒子群算法对UHPC梁桥进行结构优化设计;针对传统粒子群算法容易陷入局部最优的不足,基于杂交的粒子群算法,在迭代过程中增加选择杂交的操作,采用非线性自适应权重更新方法对粒子群优化算法进行改进。基于上述改进粒子群优化算法,对公路常用跨径的普通钢筋UHPC梁、预应力UHPC梁的优化设计方法进行了研究。结果表明:(1)相较于传统的粒子群算法,改进的粒子群算法具有更高的收敛速度和收敛精度;(2)普通钢筋UHPC梁的最优高跨比随着跨径的增加而减小,造价逐渐提高;预应力梁的最优高跨比随着跨径的增大先减小后增大,造价逐渐提高。(3)在经济梁高的基础上,减小梁高会大幅增加底板的宽度以满足结构刚度的需要,造价也将大幅增加。

In order to make full use of the superior mechanical properties of ultra-high performance concrete(UHPC)and reduce the cost of bridges,particle swarm algorithm is used to carry out structural optimization design for UHPC beam bridges.In view of the shortage that traditional particle swarm optimization algorithm is easy to fall into local optimization,hybrid based particle swarm optimization algorithm increases the operation of selecting hybrid in the iterative process,and uses nonlinear adaptive weight update method to improve the particle swarm optimization algorithm.Based on the improved particle swarm optimization algorithm,the optimization design methods of ordinary reinforced UHPC beams and prestressed UHPC beams with common highway spans are studied.The results show that:①Compared with the traditional particle swarm optimization algorithm,the improved particle swarm optimization algorithm has higher convergence speed and convergence accuracy.②The optimal height span ratio of ordinary reinforced UHPC beams decreases with the increase of span,and the cost per square meter increases gradually,and the optimal height span ratio of prestressed beam decreases first and then increases with the increase of span,and the cost per square meter increases gradually.③On the basis of economic beam height,reducing the beam height will greatly increase the width of the bottom plate to meet the needs of structural stiffness,and the cost will also increase significantly.