Abstract: In order to study the influence of different plugging conditions on borehole blasting effect,the method of model
test and numerical simulation was used to analyze the motion law,rock mass damage characteristics,strain distribution of borehole
surface and pressure characteristics of hole wall in charge section and non-charge section under different plugging conditions,
so as to reveal the mechanism of hole plugging on blasting effect. The results show that the blocking time of clay is the
longest (about 8. 7 ms),which is 3 times and 2 times that of water bag and anchoring agent,respectively,and it is the best among
the three materials. The use of clay blockage can not only save the amount of explosives,but also increase the circulation
footage. In terms of hole wall pressure,the influence of clay on the charge section is negligible. However,after it plays a blocking
role,the hole wall pressure in the air section rises to 13 times of the corresponding position in the non-blocking condition,
and the blocking section also reaches about 3 times. In addition,the damage range of the clay blockage condition is larger,
which is mainly reflected in the air section and the blockage section,while the damage range of the charge section is less different
from that of the non-clogging condition. Due to the extension of the action time of the explosive gas by the clay,the damage
development time of the rock mass is about 1. 7 times that of the non-clogging condition.

Key words: blast-hole blocking,blocking material,model test,numerical simulation,motion characteristic