Research On The Stability Of Soft And Cracked Rock Under Blasting Vibration In Jinshandian Iron Mine

Soft and cracked rock has special mechanical properties, the damage mechanismis very complexity under the action of blasting vibration, so the study of soft andcracked rock damage and the effect on soft rock roadway under blasting Vibration isundoubtedly of great practical significance and research value.Make the status survey for the area of soft and cracked rock,including rock type，occurrence state， failure characteristics etc…master the present situation of softrock,rock mechanical test was used in the experiment. The results showed that kaolin,kaolinization granite, skarn marble, powder magnetite is in the grade of broken andsoft.Establish and implement the blasting vibration monitoring test of medium-lengthhole blasting, and get the blasting seismic wave attenuation rules by regressionanalysis.On this basis, establishment the blasting vibration dynamic contrast evaluationsystem by using the method of dynamic stress ratio. The results show that adjacenttunnel get great damage of blasting vibration.Crack growth theory to build a cumulative damage effect calculation model in softrock region. Using the measurement data to analysis the cumulative damage of the eastsoft rock region,which region under the blasting effect.The results showed that blastingvibration has the most influential effect kaolinization granite, skarn marble inJinshandian iron mine.Building Jinshandian iron mine roadway model，and than study the dynamicresponse of roadway model under the blasting seismic wave. Analysis results show thatblasting Vibration will damage the roadway surrounding rock, the damage will increasewith the times of blast.Based on the the law of soft rock roadway instability and support mechanism. Theresult shows that154Kg is the maximum single explosive dosage in medium-lengthhole blasting,and design the ways of initiation when the total charges is more than850Kg, and improve the support system.Through the research above and technique project adopted，the paper analyzed thesoft and cracked rock damage and the effect on soft rock roadway under blastingVibration，and the on the same types of mine has a certain reference.