Abstract: Compared with split-set,the self-swelling split-set has the advantages of convenient installation,high anchorage
force and constant resistance slip,but its anchorage mechanical properties in different quality of rock mass are still unclear.
Based on the field test at the level of 2 655 m in Huashugou Copper Mine,the pulling test was carried on the rock bolt equipped
with different lengths of anchorage in different rock masses,and the optimal anchorage length and anchorage effect of
the self-swelling split-set under different rock masses were analyzed. In order to further explore the anchorage mechanical properties
during the rock bolt,the numerical simulation of the pulling process was carried out by Ansys software,and the normal
stress distribution characteristics of rock bolt-rock interface under the condition of different length of the anchor agent and different
quality of the surrounding rock were analyzed. The results show that for intact,relatively intact and relatively fractured
hard rock masses in mining areas,the optimal charge lengths for self-expanding slit tube bolts are 30 cm,30 cm and 45 cm,respectively.
At these optimal charge lengths,their anchoring forces are 2. 30,2. 87 and 3. 88 times that of conventional slit tube
bolts,respectively. The anchoring force of the self-swelling split-set is linearly correlated with the length of the anchor agent.
The length of anchor agent affects the anchorage force mainly by affecting normal stress distribution area,while the rock mass
affects the anchorage force mainly by affecting normal stress of the bolt-rock interface. This paper reveals the anchorage mechanical
properties of self-swelling split-set under different rock mass,which not only provides a theoretical basis for optimizing
the design and use of self-swelling split-set,but also has important guiding significance for the support design in practical mining
engineering.