某平板结构现场加载试验及有限元分析

On-site loading experiment and finite element analysis on a flat slab structure

广州某核心筒-板柱结构工程中的板柱节点内埋型钢架。为检验该板柱结构的静载承载能力、变形能力及其他受力性能,采用现场加载测试及有限元分析进行了研究。试验采用分十级将加气混凝土砌块堆加到2m高的加载方法,采集楼板在各级检验荷载作用下的挠度及混凝土的应变情况。试验结果表明,在试验荷载达到设计荷载标准组合(7kN/m2)时,结构未出现可见裂缝,结构位移及应变均处于线弹性阶段;在试验荷载达到荷载标准组合2倍(14kN/m2)时,出现了少量裂缝。采用ABAQUS软件进行了有限元分析,其中楼板采用了分层壳单元。试验结果与有限元分析结果吻合良好,有限元分析得到的极限承载力要远高于结构的试验荷载,表明了本结构具有较高的安全度。分析也表明节点区内置的型钢架除了原设计设想中的提高抗冲切、抗剪能力外,其在抗弯方面也起到了明显的作用。

For testing the static load carrying capacity, deformation capacity, and other mechanical behavior of a structure in Guangzhou, which is a core-tube-fiat-slab structure, section steel shelf embedded in joint zone, the on-site loading experiment and finite element analysis were carried out. The testing load, which was loaded by aerated concrete bricks to 2m height, was divided into ten steps. In each testing load step, the deflection and concrete strain were collected. The experiment results show that, when the testing load increases to standard combination design load （TkN/m2） , the structure does not appear visible cracks and the structural displacement and strain are still in linear elastic stage, when the testing load achieves 2 times of standard combination load （ 14kN/m2 ）, only a small amount of cracks appear. Finite element analysis software ABAQUS was used for further study, in which layered shells were used for floors. Experimental results and finite element analysis results agree well, and the ultimate bearing capacity of the finite element analysis is much higher than testing load, indicating that this structure has a higher level of security. Analysis also indicates that, in addition to the original design idea of improving punching and shearing ability of the joint zone, the built-in section steel shelf also plays significant roles in the bending capability of the joint.