浅议预应力锚杆结构的构成与划分
Discussion of the Composition and Division of a Prestressed Anchor Structure

国内规范及工程实践中把锚杆结构划分为锚固段、自由段及锚头段,这种划分方法已经不能满足锚杆技术发展需求,建议增加一种将杆体划分为黏结段、非黏结段与张拉段的划分方法。工程中普遍存在将黏结段作为锚固段使用的现象,锚固段与黏结段、自由段与非黏结段的功能不同,不能混淆。止浆塞是物理上将锚固段与自由段分开的关键构件,不设置止浆塞则法确定锚固段的起止位置及长度,也就法对锚固段进行准确设计计算。实际工程中止浆塞的设置位置造成拉力型锚杆带有拉压型锚杆的受力特征。为保证锚固段置于假定破裂面以内的稳定土体中,需将止浆塞设置在假定破裂面以内1~2 m处。
The method that anchor structure is divided into fixed length, free length, and anchor head using industry standards and engineering practices, but it has been found that this approach cannot meet the requirements of anchor technology development. Therefore, another method is suggested in this study that employs a body rod as the anchor will be divided into bond, non-bond and tension lengths. Erroneously employing in the bond length as the fixed length has been the rule in numerous engineering projects. The functions between the fixed length and bond segment are different, so the free and non-bond segments cannot be confused. The packer is the key physical element that distinguishes the fixed length from the free length, the start-stop position and fixed length are unknown without a top-grouting plug, so that the fixed length is often not accurately designed or calculated. The tension-type anchor is partially characterized by a tension-compression anchor and, in practice, is the actual position of the packer. To ensure the fixed length of the anchor outside of the assumed stability slip surface and within the stability of the soil layer, the packer should be set outside of the assumed stability slip surface at 1~2 m.