拉力型锚杆锚固段传力机理的全过程分析方法

An Analysis Method of the Whole Working Course for the Force Transferring Mechanism in Fixed Segment of Tensile-type Anchor Bar

现行规范和技术标准有关锚杆设计均假定剪应力均匀分布,这种设计方法并不符合锚杆受力的实际情况,通过对锚杆抗拔模型试验数据分析,绘制了锚杆在试验荷载作用下沿锚杆全长分布的剪应力-位移曲线。其次通过对锚杆抗拔模型试验结果的拟合分析,提出了锚杆锚固段剪应力与位移之间关系的弹塑性本构模型,结合锚杆受力的基本方程,得出了分析圆柱形锚固段和底端有锚定板的锚固段从弹性工作阶段到锚杆与岩土体界面滑移的全过程的分析方法,并在此基础上编制程序,对两种锚固段的岩石锚杆在任意荷载作用下的受力特征做了对比分析。同时文章还提出了决定锚杆承载力的特征作用段的概念。

The present design specification and technical standard assume the shear stress of anchor distributed uniformly along the anchor, but this design assumption does not correspond to the actual working status of anchor bar. In this paper,a shear stress -displacement curve was drawn along anchor full -length under test loads by analyzing the data of the model experiment on pulling resistance of anchor bar. This paper proposed a constitutive model about the relation of shear stress and displacement by fitting the result of model experiment on pulling resistance of anchor bar, and deduced the analysis method of analyzing the whole working course from elastic to elastoplasticity slide of columniform fixed segment and the fixed segment with anchor slab at the foot of anchor bar, a program has been compiled on this basis ,the mechanical feature of two kinds of fixed segment under any load is compared. And this paper puts forward the concept of feature segment determing the bearing capacity of anchor.