Experiment Research Of Slope Rock Damage Under Blasting Loading

Under the effect of the blasting loading, the shock effect from the bursting stress wave will result in rock damage and affect the integrality of the rock, thus doing harm to the safety of the project and increasing the later consolidation costing. In the progress of the rock digging, blasting damage control is the one of the most committed technical question in engineering. According to field test of slope blasting damage which uses digital bore panoramic camera system to record the test rock holes before and after the blasting , the crevice change on the internal surface of the hole can be got by studying the pictures of the holes before and after the blasting .By means of combining the digital picture analysis technology with Matlab calculating progress which is based on box-counting dimension calculating theory, box-counting dimension of the picture crack is calculated. Finally, the damage feature of slope under blasting load effect is numerically simulated with Flac^3D.The primary research achievements are as following:1. The influencing factor of deep hole blasting is analyzesed , then taked a example of high slope blasting in GuangHe expressway, the blasting parameters are redesigned and used in the blasting construction. The result is that half-role rate was high and the slope is level up. So the blasting effect was satisfactory.2.The digital bore panoramic camera system is used in the field test of slope blasting damage and the test result shows: Due to excessive single charge , the range of damage impact of the retention rock which has presplitting hole reached 4m . and to the higher lever slope foot rock is about 1.5m , the range of damage is about 1.8m .3.Through the drilling rocks'crack surface fractal features, the calculate method of common fractal dimension is analyzed and the box-counting dimension for this paper is determined. Used the program which based on the Matlab calculation digital image of box dimension as the main calculating method before and after explosion, calculated the images of box dimension of the 1st hole and the 3rd hole, found that the box dimension increased after the explosion and with some rules, all of these show that blasting have damaged the slope. Using this method to calculate the box dimension of damaged rock surface crack under blasting load, it has good usability, providing a new research ideas to determination the damage scope.4.Flac^3D is used in the numerical simulation of damage character of slope blasting , the damage extension under blasting load effect and the develop progress were got. The damage area of the rock does not appear at 0.2ms after explosion but finish about at 5ms after explosion. Without the consideration of effect of joints in the rock, the damage depth of in the simulation is about 3.2 meters, which is a little less than the result of field test.