新型伞状抗拔锚的室内试验及研究

针对传统锚杆的不足,设计出一种新型伞状抗拔装置,并制作出模型对其展开拉拔试验。试验包括锚头无灌浆和灌浆的伞状锚拉拔试验两组以及一组用于对比的竖直抗拔桩拉拔试验。试验结果表明:新型伞状锚的抗拔性能要优于传统的竖直抗拔桩,且锚头灌浆伞状锚的抗拔性能最好。在此基础上运用有限元软件模拟试验过程,验证了模型试验的可靠性。通过对其受力机理的研究,指出伞状锚主要依靠锚头兜住的土体重量以及兜住土体与未兜住土体之间的抗剪强度来提供抗拔力,并据此提出伞状锚的极限承载力特征值估算公式,为伞状锚的工程应用奠定了基础。

EXPERIMENTAL STUDY OF A NEW TYPE UMBRELLA-SHAPED ANTI-FLOAT ANCHOR

A new type umbrella-shaped anti-float device is designed and manufactured to perfect the traditional anchors and the model test is adopted to analyze the pull capacity.There are two groups of pull-out tests for umbrella-shaped anchor with and without grouting at anchor head.And a group of vertical pile drawing tests is done.The results indicate that the anti-float performance of the new type anchors is superior to that of over traditional vertical piles.Moreover,umbrella-shaped anchor with grouting at anchor head is better.And the reliability of the results is proved through finite element analysis.According to the mechanical analysis of the umbrella-shaped anchor,it is pointed out that the bearing capacity depends on the weight of soil pole wrapped by the anchor head and the shear strength along the interface of soil pole.Therefore the ultimate bearing capacity estimation formula of the umbrella-shaped anchor can be presented,which establishes the foundation for the engineering application of umbrella-shaped anchors.