Testing and Analysis of Influence of Blasting on Soft Rock Roadway Loose Zone

In view of that charge quantity of roadway blasting construction is increasing, expansion of crack in rock mass is promoted and make the loose zone circle of surrounding rock increase. According to the field construction, loose circle radius of surrounding rock before and after blasting are tested, and the influence of blasting construction on extension of loose zone is analyzed. The analysis results show that radius of loose circle after roadway stability is about 1.8 m, and 10% of which is caused by blasting effect, influence range of blasting dynamic load is 25 to 30 m. By supporting parameters adjustment, increasing length of anchor, safety and reliability of the supporting is improved. Finally, from the aspects of blasting parameters and charge structure, the paper proposes measures for reducing dynamic load strength of roadway blasting.