附加张力装置对注浆式榫槽接头力学性能的影响研究

Effect of Auxiliary Tension Device on Mechanical Properties of Grouted Mortise-tenon Joint

为研究注浆式榫槽接头附加张力装置的作用特性,在论述接头附加张力装置构造的基础上,基于接头试验结果分析加力棒位于不同受力性质区域的特性,明确附加张力装置的作用是延缓破坏和增加接头延性;然后,以长春装配式地铁车站结构为例,对其所采用的各种类型接头的附加张力装置进行实际作用分析;最后,基于注浆式榫槽接头算法针对不同附加张力装置的设置从预紧力大小和加力棒位置两方面对接头承载性能影响进行研究。结果表明:对于设置附加张力装置的接头,建议将加力棒设置在受拉侧,轴力较小时,适当增大加力棒预紧力值可以提高接头后期承载能力;较大预紧力值对接头承载非线性段起到明显作用,但对线性段影响甚微。对于附加张力装置在受拉侧接头,当预紧力足够大时,接头构造允许范围内将加力棒设置在距中心轴一定距离处能够发挥加力棒对接头后期承载的提升作用;对于附加张力装置在受压侧接头,应避免较大加力棒预紧力并尽量设置在距离中心轴较近位置。

To study the mechanical characteristics of auxiliary tension devices for grouted mortise-tenon joints,the characteristics of the pre-tightening steel bar under different stress property areas were analyzed.The function of the auxiliary tension device is to delay damage and increase joint ductility.Considering the Changchun prefabricated metro station structure as an example,the practical effects of auxiliary tension devices on various types of joints were analyzed.Based on the algorithm of grouted mortise-tenon joints,the influences of the settings of different auxiliary tension devices on the bearing capacity of joints were analyzed from the two aspects of the preloads and the positions of the pre-tightening steel bar.The results showed that for joints with auxiliary tension devices,it was recommended to set the pre-tightening steel bar on the tension side;when the axial force is small,appropriately increasing the preload value of the pre-tightening steel bar can improve the later bearing capacity of the joint.A larger preload had an obvious effect on the nonlinear bearing stage of a joint but had little effect on the linear bearing stage.For a joint with an auxiliary tension device on the tension side,when the preload was sufficiently large,setting the pre-tightening steel bar at a certain distance from the central axis within the allowable range of the joint structure increased the elevating effect of the pre-tightening steel bar on the later bearing stage of the joint.For a joint with an auxiliary tension device on the compression side,avoiding a large preload on the pre-tightening steel bar and setting it closer to the central axis is recommended.