混凝土桥台水化热仿真分析与裂缝处理

Simulation Analysis of Hydration Heat of Concrete Abutment and Crack Treatment

【目的】针对混凝土桥台台身在施工期间产生竖向裂缝的问题,对该桥台温度场与应力场进行数值模拟。【方法】通过Midas FEA NX软件,对台身混凝土内外部温度、应力进行了水化热仿真分析。【结果】分析结果表明:台身混凝土内外部温差较大,台身混凝土外部拉应力超出了实测抗拉强度(72~336 h);将温度场、应力场分析结果与该桥台台身实际裂缝情况进行对比分析,找出了桥台台身开裂原因;将实测裂缝情况与仿真模拟结果对比分析,发现Midas FEA NX软件可有效分析混凝土水化热温度、应力变化情况。【结论】结合该桥台台身裂缝情况与仿真分析结果,对该桥台台身的裂缝提出了相应的处置建议,并在裂缝处理完成约半年之后对裂缝进行了复查,发现其表面稳定,未有扩展现象。

[Purposes]In order to analyze the problem of vertical cracks in the concrete abutment body during construction,the temperature and stress fields of the abutment were numerically simulated.[Methods]The hydration heat simulation analysis of the internal and external temperature and stress of the abutment body concrete was conducted through Midas FEA NX software.[Findings]The analysis re⁃sults show that the temperature difference between the inside and outside of the abutment concrete is large,and the external tensile stress of the abutment concrete exceeds the measured tensile strength(72~336 h);The analysis results of temperature field,stress field and the actual cracks of the abutment body are analyzed to find out the reasons for the cracks of the abutment body;by comparing the measured cracks with the simulation results,it is found that the Midas/FEA NX can effectively analyze the tempera⁃ture and stress changes of concrete hydration heat.[Conclusions]Combined with the cracks of the abut⁃ment body and the simulation analysis results,the corresponding disposal suggestions are put forward for the cracks of the abutment body.About half a year after the crack treatment,the cracks are rechecked,and the surface of the cracks is stable without expansion.