PBL剪力键承载力影响因素和计算公式研究

由于采用了不同的PBL试件,考虑了不同的影响因素,国内外现有的PBL剪力键承载力计算公式差异较大。本文设计、制作了20组不同的PBL试件共59个,完成了极限承载力试验,研究分析了各种因素对PBL键承载力的影响,并在此基础上提出了PBL键承载力计算公式。结果表明,影响PBL键极限承载力的主要因素是钢板孔洞大小、贯通钢筋的大小和强度、混凝土强度和箍筋强弱;其次是每个试件的孔洞个数和贯通钢筋个数以及试件尺寸等。本文提出的PBL键承载力计算公式较全面地考虑了上述各主要因素,物理意义明确,与其他公式相比,其计算结果和本文的试验结果最为吻合。该公式可用于PBL键的设计计算。

Study of influence factors and formula for the bearing capacity of PBL shear connectors

The calculated bearing capacity of PBL shear connectors got from the current formula put forward by the specialists at home and aboard differs a lot because of difference between PBL test samples adopted and different consideration of the influence factors.In this paper,20 different groups of PBL test pieces,59 in total were designed and made.The ultimate capability tests of the 59 test pieces were accomplished.The influence of all kinds of factors on the ultimate capability of PBL were studied and analyzed,and a new bearing capacity formula of PBL shear connectors on the base of the experiments were put forward.The results show that the size of the holes on the steel plate,the size and strength of perforating rebar,the strength of concrete and the ratio of stirrup reinforcement are the main factors influencing the ultimate capability of PBL.The secondary factors are the number of holes and perforating rebar,the size of each test piece and so on.The formula put forward by the author has considered of the main influence factors mentioned above and gives definite physical meaning.Compared with the other formula,the calculated results got from the formula is the most close to our test results.The formula can be used for the design and calculation of PBL.