弯曲应力引起的预应力混凝土箱梁开裂

Crack in prestressed concrete box girder due to bending stress

应用弯曲应力理论,研究了预应力混凝土箱梁弯曲裂缝产生的位置、范围及宽度,分析了产生裂缝的原因。发现在预应力混凝土桥梁中,跨径越大,在箱梁内对称挠曲的纵向弯曲应力是主要的,而偏心荷载引起的扭转应力是次要的;弯曲应力是预应力混凝土箱梁开裂的主要原因,单一原因产生很大裂缝的情况是很少的,但与其他原因一致作用时就会产生开裂。

To the prestressed concrete box girder,the crack location,crack propagation extent?crack width and its reasons were studied with the theory of bending stress.It was found that in large span box girders, the longitudinal bending stress due to symmetric deflection is primary while the distorting stress due to eccentric load is secondary; bending stress is the main reason that causes cracks in prestressed concrete box girders,besides,it is infrequent that one single reason can cause relatively large cracks, while it can cause cracks with other reasons.