预应力锚下混凝土局部承压横向应力的分布规律

针对某桥预应力T梁预制过程,拟配C50混凝土制成实体模型,在压力机上对锚头进行施压试验,测出了锚下混凝土横向应力变化规律;建立有限元模型,并计算横向应力;通过试验结果与有限元计算结果的比对和拟合,得出了较为适用的求解锚下横向应力的经验公式,对其求极值可得出锚下最大横向应力及其位置.并认为在实际工程设计中,若对锚下30cm深周边混凝土进行一定约束,可有效抑制梁端横向裂缝的产生.

Transverse Stress Distribution in Locally Precompressed Concrete Beam Under Anchor Slab

A physical model of T-shaped beam made from C50 concrete was provided to investigate the prefabricating process of those types of prestressed beams for a bridge,and a compression test was carried out to it on a press.The results showed that how the transverse stress changes in concrete under an anchor slab.With an FEM model developed,the transverse stress was calculated.Comparing the calculated results with tested ones and fitting them,an empirical formula was given to practically solve the transverse stress under anchor slab.Then,the maximum transverse stress and its position can be found out by extremum method.It is confirmed that in detail design the transverse cracks occurring on beam ends can be efficiently restricted if the concrete beam's periphery 30 cm below the anchor slab is constrained to a certain extent.