某桥中跨合龙段底板纵向裂缝成因分析

The genetic analysis of longitude crack midspan closure section soleplate of a bridge

针对某预应力混凝土连续箱梁桥合龙段底板纵向裂缝,采用空间有限元分析程序分析了张拉中跨合龙束后的空间效应,计算结果表明,底板纵向裂缝产生的主要原因是底板纵向预应力过大,由于泊松比效应,导致混凝土横向拉应力超过混凝土抗拉强度设计值。

Aiming at the longitude crack closure section soleplate of a prestressed concrete continuous box beam bridge, the three dimensional effect of tension midspan closure section was analyzed with the spatial finite element analysis program. The calculation result proved that the main genetic reason of soleplate longitude crack was the oversize of longitude prestressing force, the cross tensile stress of concrete exceed the tensile resistance design load was caused by the poisson effect.