焊接锚板型地脚螺栓抗拔承载力的试验研究及理论分析

EXPERIMENTAL RESEARCH AND THEORETICAL ANALYSIS ON THE UPLIFT BEARING CAPACITY OF WELDED ANCHOR PLATE TYPE ANCHOR BOLT

地脚螺栓锚固端焊接锚板形成锚板型地脚螺栓,该机械锚固可显著提高地脚螺栓的锚固承载力及可靠性。以地脚螺栓直径、锚固长度为参数,设计并制作3种直径、3种锚固长度地脚螺栓抗拔承载力试件并开展抗拔承载力试验,考察其荷载-变形特性及破坏模式,并与光圆地脚螺栓的承载力特性、破坏模式进行对比。结果表明:抗拔承载力随锚固长度增大而增加,与光圆地脚螺栓相比,锚板型地脚螺栓的抗拔承载力提高约4~6倍;锚板型单个地脚螺栓的锚固承载力并不与其直径成正比。为此,开展锚板型单个地脚螺栓抗拔承载力的模拟分析,考察上拔受力时的传力机理及承载力变化规律。基于试验研究、模拟分析以及现行规范的相关规定,提出了锚板型单个地脚螺栓的锚固承载力计算理论。

The anchor plate type anchor bolt is fabricated by welding an anchor plate and four stiffeners at the end bolt.This mechanical anchorage can significantly improve the anchorage bearing capacity and reliability of anchor bolts.With the diameter of the anchor bolt and the length of anchorage as the parameters,the anchor bolts with three diameters and three anchorage lengths were developed,and the uplift bearing capacity test was carried out to investigate its load-deformation characteristics and failure modes,the bearing capacity and failure modes were compared with that of circular anchor bolts.The results showed that the uplift bearing capacity increased with the increase of anchorage length,comparing with the circular anchor bolts,the uplift bearing capacity of anchor plate type anchor bolts increased about 4~6 times.The anchorage bearing capacity of single anchor plate anchor bolt was not directly proportional to its diameter.The changing regularity of the bearing capacity and the force-transferring mechanism of uplift force were investigated by carrying out the simulation analysis of uplift bearing capacity of single anchor plate type anchor bolt.Based on the experimental research,simulation analysis and relevant regulations of the existing codes,the calculation theory of anchorage bearing capacity of single anchor plate type anchor bolts was put forward,which could be referred to engineering design and application.