Smooth blasting starts the cutting eye first, then the auxiliary eye, and finally the peripheral eye, while presplitting blasting starts the peripheral eye first, forming a smooth presplitting surface along the peripheral eye. Because of the existence of this pre-splitting surface, it can reflect and buffer the detonation waves of post-blasting off-cut and auxiliary holes, reduce the damage of detonation waves to surrounding rock, maintain the integrity of rock mass, and make the excavated surface after blasting neat and regular.
Presplitting blasting
Pre-splitting blasting refers to blasting through cracks with a certain width on the design contour line before blasting in the main blasting area when excavating stone. In order to buffer and reflect the vibration wave of excavation blasting and control its destructive influence on the reserved rock mass, a relatively flat excavation contour line can be obtained.
Presplitting blasting is not only widely used in vertical and inclined excavation walls; Presplitting blasting is also used for regular surfaces, twisted surfaces and horizontal foundation surfaces. Presplitting blasting is suitable for weak rock strata with poor stability and need to control the excavation contour.
smooth blasting
Smooth blasting is a kind of controlled blasting technology, which keeps the new wall flat and has no obvious damage. It is characterized in that a row of smooth blasting holes with hole spacing matching the minimum resistance line are drilled on the designed excavation contour line, and uncoupled charging or other special charging structures are adopted. After the main body of the excavation is blasted, the charges in the smooth blasting hole are simultaneously detonated, forming a flat excavation surface that runs through the smooth blasting hole.
References:
Presplitting Blasting-Baidu Encyclopedia Smooth Blasting-Baidu Encyclopedia