Study On The Mechanism And Application Of Blasting Fragment Size Control

The rock blasting fragment mechanism and rock lumpiness control theory and rock blasting technique were studied by theoretic and field test according to dimension stone need of breakwater project, and the research results were applied to the breakwater project.The main research results are as follows.1 Rock blasting damage was studied by analyzed the classical solid mechanic of rock blasting fragmentation mechanism. According to Taylor and Chen and Kuszmaul’s research results, rock blasting damage mechanism was studied, and rock blasting damage model was put forward from crack density and damage evolve rule and stress-strain expressed by effective modulus. The fractal evolution of breaking in rock blasting was put forward in this thesis.2 By analyzing explosive energy theory and detonation velocity and specific charge and rock fragmentation size forecast, rock blasting lumpiness control theory was studied. Rock major structure and construction of charge played an important role in rock blasting lumpiness distribution, the better blasting quality can attained if adopted reasonable decoupling index, for that the rock shatter index was decreased, and fragmentation area was enlargement.3 Rock blasting lumpiness distribution index for rock and geological structure district was put forward, and according to six basic indexes the stoneworks was divided into different blasting lumpiness mining district. By compared with different loaded constitution, nonuniform and decoupling charge could achieve the best quality of blasting, and the lowest ore fines rate.4 The function relationship between ore fines rate and rock property (specific charge, toe burden, distance between holes, loading density, explosion energy) was built. The forecast function of blasting lumpiness and the optimized design program for blasting parameters were studied in this paper. 5 On the basis of theoretical research and field test, the breakdown blasting was designed for controlling rock lumpiness. Engineering blasting provided timely stone for breakwater project, and ensured that the underwater engineering of defence construction was accomplishment on time.