摘要
对大跨径连续刚构桥中跨底板混凝土在底板预应力筋作用下可能纵向开裂的现象进行了分析,阐述了产生这种现象的力学机理。根据一座跨径布置为140 m+268 m+140 m的单箱单室预应力连续刚构桥的结构与设计特点,对该桥在底板预应力作用下的空间效应不利影响进行了分析,提出了避免跨中箱梁底板纵向开裂、底板混凝土向下崩出和腹板竖向拉应力过大的建议,可为大跨度连续刚构桥的设计提供参考。
This paper analyzes the phenomenon of possible longitudinal cracking in the bottom slab concrete of main span of long span continuous rigid-frame bridge due to action of the prestressing strands in the slab and explains in details the mechanical mechanism the phenomenon is caused. In accordance with the structural and design characteristics of a prestressed concrete continuous rigid-frame single cell single box girder bridge with span arrangement 140 m＋268 m ＋ 140 m, the paper further analyzes the adverse influences of spatial effect under the action of the prestressing in the bottom slab and suggests measures that can avoid the longitudinal cracking in the bottom slab of the main span, downward bursting of the concrete there and excessively great vertical tensile stress in the webs. The results of the analysis can serve as reference to the design of long span prestressed concrete continuous rigid-frame bridges.
出处
《世界桥梁》
北大核心
2006年第4期36-39,63,共5页
World Bridges
关键词
刚构桥
预应力筋
裂缝
空间效应分析
rigid-frame bridge
prestressing tendon
cracking
spatial effect analysis
