Strategy predicated on accurate lithology delivery
In the process of stone blasting, the newest physical and you will mechanized features of rock was positively you to definitely of your own main affairs one dictate the result off stone blasting 21 . There was have a tendency to an unclear with the knowledge that this new harder the brand new rock, brand new more complicated it’s becoming blasted in the present technology business. Yet not, the latest blasting impression is not just as asked during the engineering methods. Alternatively, it’s been unearthed that the latest stiffness from stone isn’t higher because the equipment use of explosives is actually large twenty-two .
Depending on the breaking procedure out-of material blasting 23 , the ability create from the explosives serves with the rocks by the treat revolution and expansion tension regarding detonation gasoline when an explosive explodes on the stones. A perfect destruction off rocks is due to the experience worry created by the brand new burst surpassing their energy restrict, and this indicates that the latest smashing condition are directly associated with the brand new burst time plus the mechanical features of your own rock. In other words, according to the certain conditions off equipment explosive consumption setting, kind of, and you can free surface, the new fees wide variety is certainly caused by determined by new mechanical characteristics regarding material to attain a specific smashing effect. For this reason, the new lithology shipment is the number one basis for choosing the new product usage of explosives twenty four .
When you look at the an out in-breadth examination of the brand new lithology off hard-rock, it is unearthed that high stress provides a critical influence on the fresh blasting techniques and stone cracking feeling. The results also demonstrate that large-web site stress handling and you can blasting loading aren’t a couple independent process, to the contrary, they work for the synergy, plus the active unloading keeps a serious impact 25 . For this reason, the delivery off hard-rock is the vital thing on design out-of a great segmented charge getting blasthole.
Group regarding blasthole rock strata
From the conventional blasting techniques, brand new lithology distinction along side great time hole depth isn’t noticed about blasting framework. For this reason, just one charges structure is actually adopted. About superimposed material size which have silky and hard inclusions, the newest weak interlayer’s compression and you may tensile resistance power are particularly reduced in contrast to you to definitely in the advanced stone structures, nearly minimal. At the time martial arts dating site free, the fresh weakened interlayer can very quickly get to be the flood channel of your own detonation gasoline and you may weaken the crushing and you will throwing aftereffect of the new high-pressure energy made by the brand new burst. Additionally, when it comes to high hard-rock instead explosion splits, it is challenging to split considerable stones utilising the second crushing idea from cut off stone crash about organizing process owed in order to a failure interlayer twenty six . For this reason, the new department regarding soft-rock and hard material is a vital step in the framework strategy.
The lithology data of the corresponding blastholes are obtained by intelligent drilling rigs. According to the hardness of the lithology, the blasthole rock strata are divided into 7 categories, and lithology classification numbers range from Type 1 to Type 7 27 . In order to facilitate the design and calculation of blasthole charge structure, the adjacent strata with similar lithology are combined and grouped. The lithology is divided into two groups of soft rock and hard rock, denoted as \(s\) and \(h\) , respectively. The classification rule of soft rock and hard rock is that the strata numbered 1, 2, 3, and 4 are soft rocks, and rock strata numbered 5, 6, and 7 are hard rocks. The grouping diagram of blasthole rock strata is shown in Fig. 4: H refers to the blasthole depth, Rs means the thickness of soft rock, and Rh means the thickness of hard rock.
