Prediction Method on Blasting Fragmentation of Rock Mass Mechanics in Mining Area Based on Measurement While Drilling
In mining operations,the distribution of rock mass blasting fragmentation has a significant impact on loading,transportation,and crushing costs.There are many known methods for predicting the blasting fragmentation,but none of them are fully applicable to the evaluation of blasting fragmentation of non-pillar sublevel caving method.The main reason for this is the variability of the underground environment and the lack of data to fully characterize the rock mass.With the intelligent development of drilling equipment,measurement while drilling(MWD)system has become an important tool for providing more on-site rock mass information.The MWD data of 175 boreholes in 17 blasting cycles were collected in the stope of non-pillar sublevel caving method in a mining area,and the rock mass fragments of each blasting cycle were completely recorded in the photos.The rock mass morphology before blasting was divided into five types using MWD data,and the rock fragments after blasting were divided into four types using the average fragmentation index X50.The relationship between rock mass types and blasting fragments was studied,and a prediction model of blasting fragments of non-pillar sublevel caving method was proposed.The results indicate that intact rock masses tend to produce finer blasting fragments.In intact and slightly fractured rock masses,the challenges and uncertainties faced by charging and blasting processes are relatively small,so the corresponding degree of fragmentation can be better predicted.There is a positive correlation between the discontinuity of rock mass and the size of blasting fragments,thus tending to produce larger blasting fragments.
Non-pillar sublevel caving methodMeasurement while drillingBlasting fragmentationBlasting fragmentsPrediction model
万方数据
维普
