软基差异沉降对现浇梁质量影响数值模拟研究

Numerical Simulation Study on the Effect of Uneven Settlement on the Quality of Cast-in-Place Beam

为了掌握软基差异沉降对现浇梁体质量的影响,运用有限元软件ABAQUS进行数值模拟,通过分析不同龄期、不同差异沉降条件下,早龄期混凝土梁构件的应力应变的变化规律。结果表明:在混凝土早龄期阶段受到过大的不均匀位移荷载,现浇梁体内部将出现塑性区,这将对预制梁的质量造成重大的危害。采用极限压应变作为判据时,结构物在1 d龄期能够承担的最大差异沉降为12 mm,在2 d龄期能够承担的最大差异沉降为14 mm,在3 d龄期时能够承担的最大差异沉降为14 mm,在7 d龄期能够承担的最大差异沉降为15 mm,在2 8d龄期能够承担的最大差异沉降为17 mm。

In order to master the influence of differential settlement on the quality of cast-in-place beam,the finite element software ABAQUS is used to simulate the stress and strain of the early age concrete beam members under different ages and different settlement conditions. The maximum allowable difference in the quality of cast-in-situ beam in prefabricated soft foundation is given. The results show thatwhen concrete is subjected to excessive uneven displacement load in its early age,plastic zone will appear the cast-in-place beams,which will cause great harm to the quality of prefabricated beams. When the ultimate compressive strain is used as the criterion,the maximum uneven settlement of the structure is 12mm at 1 day,and it is 14mm after 2 days,14 mm after 3 days,15 mm after 7days. The maximum uneven settlement at 28 days is 17mm. Therefore,the quality of cast-in-place beams caused by differential settlement of soft soil can be effectively controlled by foundation treatment before the construction of prefabricated beams.