This new computed product use of explosives grows into the improve from material hardness

Means considering exact lithology distribution

In the process of material blasting, the newest real and you will physical functions of one’s material is actually definitely one to of your own chief items one dictate the effect regarding rock blasting 21 . There is certainly tend to a vague realizing that the South Bend escort service latest much harder new stone, the latest more complicated it’s is blasted in the modern systems industry. not, the new blasting impact is not just as questioned during the systems practices. Alternatively, it is often learned that the newest hardness from stone isn’t highest as equipment consumption of explosives try highest twenty two .

According to the breaking method off stone blasting 23 , the energy released from the explosives acts into the rocks by wonder trend and you can expansion pressure out of detonation energy whenever a volatile explodes for the rocks. The ultimate depletion of rocks is caused by the action be concerned developed by the newest burst exceeding its fuel restrict, and therefore reveals that brand new crushing state was directly connected with this new explosion opportunity therefore the technical services of your material. This means, beneath the particular requirements regarding tool volatile consumption setting, type, and you will 100 % free skin, the fresh new costs amounts is mainly determined by the brand new physical attributes out-of material to achieve a particular smashing impact. Hence, this new lithology delivery is definitely the first basis for deciding the newest product usage of explosives 24 .

Into the an out in-depth examination of the latest lithology regarding hard rock, it’s discovered that high worry keeps a significant effect on the brand new blasting techniques and you can stone cracking impression. The outcome and demonstrate that large-webpages fret handling and you can blasting packing commonly two independent processes, to the contrary, it works when you look at the synergy, as well as the active unloading keeps a critical impression 25 . Ergo, the shipments from hard rock is the vital thing to the structure off a segmented charge to own blasthole.

Group from blasthole rock strata

In the conventional blasting procedure, new lithology variation along side great time gap depth is not experienced in the blasting build. For this reason, a single costs structure is implemented. Throughout the superimposed rock bulk having softer and hard inclusions, the brand new weakened interlayer’s compressing and tensile resistance electricity are extremely reduced compared with you to definitely regarding the cutting-edge rock structures, almost negligible. At the time, the fresh new weakened interlayer can quickly become the flood route of your detonation energy and you will weaken the fresh new smashing and you may tossing aftereffect of the newest high-pressure gasoline from the fresh new explosion. Additionally, when it comes to highest hard rock in place of rush fractures, it’s difficult to split considerable stones by using the secondary crushing idea regarding block stone crash regarding the putting procedure due so you can a deep failing interlayer twenty-six . Hence, the latest division regarding soft-rock and hard rock is a vital step on the build means.

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, R_s means the thickness of soft rock, and R_h means the thickness of hard rock.