异型锚杆承载力的试验研究

Experiment Study on Bearing Capacity of Special Shaped Anchor

传统锚杆的局部应力集中现象严重,一旦局部破坏将造成锚杆整体失效。采用试验方法,通过在锚固段增设锚刺来增大锚杆承载力,研究了锚杆承载力与锚刺层数、砂浆强度、试块尺寸之间的关系;得出在锚刺强度一定条件下异型锚杆承载力与水泥砂浆强度初期呈线性关系、达到一定强度后呈非线性关系,即并非砂浆强度越大越好。从试验结果来看,单层锚刺条件下锚杆承载力随着试块尺寸的增大而增大,说明锚刺强度一定时其承载力与水泥砂浆厚度正相关。

The partial stress concentration effect in traditional rock bolt is significant, which would lead to overall failure of rock bolt. Therefore, we applied experiential method to explore the relationship between bolt bearing capacity and anchor thorn layers,strength of mortar and the block size through improving the bearing capacity of anchor by adding anchor thorn in the anchorage section. From the test, the we get conclusions that： firstly, the different bolt bearing capacity has a linear relation with the early stress of cement mortar at the early stage, while, after reaching a certain intensity, the relation would change to be nonlinear,which means that greater mortar strength does not represents better function; secondly, based on the experience results, we can conclude that under the condition of single anchor thorn, the bearing capacity of anchor increases with the size of the test cube,which represents that given a certain level of anchor thorn stress, the anchor bearing capacity is positively related to the thickness of the cement mortar.