预应力混凝土空心桩与承台连接结构抗拔研究  

Axial pull-out capacity of connection structure between prestressed concrete hollow pile and bearing platform

作　　者：黄建锋[1] 黄广龙[1] 范钦建[1] 

机构地区：[1]南京工业大学交通学院,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2014年第4期95-100,107,共7页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省普通高校研究生科研创新计划(CXLX12_0437);江苏省产学研联合创新基金(BY2012031)

摘　　要：针对预应力混凝土空心抗拔桩与承台连接强度不够的问题,采用空心桩内壁刻槽的方法改善桩头连接性能。开展预应力混凝土空心抗拔方桩填芯混凝土拉拔试验,结果显示方桩内壁光滑时填芯混凝土直接被拔出,而方桩内壁有螺纹时,填芯混凝土在所受持载达到800 kN的情况下与空心桩内壁之间的连接仍能保持良好,在空心桩内壁刻槽是提高桩与承台结构连接强度的有效方式。研究桩内壁与填芯混凝土的黏结性能,分析2种桩壁与填芯混凝土之间黏结作用机制和影响因素,发现方桩内壁光滑时由于填芯混凝土与空心桩内壁之间的黏结力不足导致试验中填芯被拔出,而桩壁有内螺纹时,内填芯混凝土受拉承载力主要取决于桩壁螺牙抗剪切强度。在此基础上,结合相关规范,对填芯混凝土设计进行探讨,为进一步研究提供参考。Aimed at problems of poor axial pull-out bearing load of the connection structure between prestressed concrete hollow pile and the bearing platform,a grooving method in the inner wall of piles was used to improve its connection performance. Experiments were conducted to test the pull-out performance of square prestressed concrete hollow piles with filling concrete,in which the filled concrete was easily pulled out when the square pile wall was smooth,whereas the connection remained good on the pulling force of 800 kN when the pile wall grooved inside. It was proved that grooving in the inner wall of the hollow square piles was an effective way to improve the connection strength. Bonding performance between the pile wall and the grouted concrete was studied and the bonding mechanism and effect factors were analyzed. It was found that when the square pile wall was smooth,the grouted concrete was pulled out due to bond strength shortage. When the pile wall had internal screw threads,the tension capacity of the grouted concrete depended mainly on the shear strength of the threads. Combining with relevant specification,the design of grouted concrete was based on the research,thus it provided useful reference for further study.

关 键 词：桩基础 桩与承台连接 内螺纹 受力机制 

分 类 号：TU473[建筑科学—结构工程]