抗拔管桩预埋机械套筒连接件轴拉承载性能试验及数值分析

Experimental Tests and Numerical Analyses on Axial Tensile Bearing Capacity of Connection Specimen of Mechanical Sleeve Embedded in Anti-extubation Pile

【目的】验证用于抗拔管桩的预埋机械套筒连接件的轴拉承载性能。【方法】完成了6组抗拔管桩张拉机械套筒连接件的轴拉试验,得到了最大破坏荷载和破坏形态,结合有限元计算结果,分析试件应力分布规律,找出应力集中点或薄弱部位。【结果】结果表明:预埋机械套筒连接件整体满足抗拉承载力要求,试件极限破坏时,表现出的主要破坏现象为套筒卡槽和钢棒墩头破坏。墩头和卡槽接触面倾斜角度减小对改善试件应力集中现象有明显效果,建议倾斜角度控制在15°以内。【结论】桩身混凝土会限制套筒连接件的变形,提高试件抗拔过程中的安全可靠性。

【Purposes】To verify the axil fensile beaning performance of pre embeded mechanical sleeve connectors used for anti-pulling pile.【Methods】The axial tension test of 6 groups of anti-pulling pile tensile mechanical sleeve connectors was completed,and the maximum failure load and failure mode were obtained.Combined with the finite element calculation results,the stress distribution law of the specimen was analyzed to find out the stress concentration point or weak part.【Findings】The results show that the pre-embedded mechanical sleeve connection specimen meets the requirements of tensile bearing capacity;when the specimen was subjected to ultimate failure,the main failure phenomena were the failure of sleeve groove and steel bar end block;the inclination angle decrease of the contact surface between the pier head and the groove has a significant effect on improving the stress concentration of the specimen,it is suggested that the inclination angle should be controlled within 15°.【Conclusion】Pile concrete limits the de-formation of sleeve connectors and improves the safety and reliability of specimens during pull-out.