新老桥墩混凝土防收缩开裂措施数值模拟与试验研究

Numerical Simulation and Experimental Study on Anti-Cracking Shrinkage Measures of Concrete of New and Old Bridge Piers

针对在既有桥墩基础上新浇筑桥墩混凝土出现开裂这一问题,提出进行二次振捣和提前洒水润湿的方式来减少开裂。结合南沙港公铁两用桥改扩建工程,通过ANSYS有限元软件建立新老桥墩混凝土有限元模型,对改善措施进行效果分析。在实际工程中进行新浇筑桥墩混凝土收缩现场试验,对试验数据进行整理并与模拟结果进行对比。结果表明:有限元模拟结果可靠,二次振捣和洒水润湿的方式可有效改善新浇筑桥墩混凝土的早期开裂情况,保证施工质量。

Aiming at the problem of cracking when newly pouring pier concrete on existing piers, a second vibrating and sprinkling wetting in advance method is proposed. An ANSYS finite element model of the concrete of the new and old bridge piers was established based on the reconstruction and expansion project of the Nansha Port road-rail dual-use bridge, and the effect of the improvement measures was analyzed. In the actual project, the newly poured bridge pier concrete shrinkage field test was carried out, and the experimental data was analyzed and compared with the finite element results. The results show that the finite element model is reliable, and a second vibrating and sprinkling wetting in advance method can effectively reduce the early cracking of the newly poured bridge pier concrete, thereby ensuring the construction quality.