New calculated equipment use of explosives increases towards the increase away from rock firmness

Means according to real lithology shipments

In the process of rock blasting, new real and you can mechanical features of material was definitely you to of your head issues you to determine the result off rock blasting 21 . There’s often an obscure comprehending that the fresh much harder the fresh material, the harder it is to get blasted in today’s engineering community. Yet not, the newest blasting impression isn’t exactly as expected when you look at the technology strategies. Rather, it’s been unearthed that this new hardness of stone is not large as the unit usage of explosives is highest twenty-two .

Depending on the breaking system out-of material blasting 23 , the power put out of the explosives serves to the stones of the wonder trend and you can expansion tension regarding detonation fuel when an explosive explodes to the stones. The greatest exhaustion regarding stones is due to the action stress developed by the fresh new explosion surpassing its strength restrict, and that indicates that the fresh crushing condition is actually directly connected with this new rush time while the physical characteristics of your stone. Simply put, within the specific criteria regarding tool volatile usage means, variety of, and you may totally free skin, the fresh charge numbers is usually dependent on the brand new mechanized attributes out-of rock to attain a certain smashing impact. Ergo, the lithology shipment is regarded as the number 1 reason behind determining the brand new device consumption of explosives 24 .

Into the a call at-depth examination of the fresh new lithology regarding hard-rock, it’s learned that higher worry enjoys a life threatening impact on the fresh blasting process and you will rock breaking effect. The results and additionally demonstrate that high-web site fret handling and you can blasting loading commonly two separate procedure, on the contrary, they work in cooperation, while the active handling has actually a life threatening effect 25 . For this reason, the newest shipment off hard rock is paramount to the design from good segmented costs getting blasthole.

Collection regarding blasthole material strata

In the conventional blasting techniques, the fresh lithology improvement along the blast hole depth is not noticed on the blasting build. Ergo, a single charges construction try implemented. Regarding the layered rock mass that have flaccid and hard inclusions, the fresh new poor interlayer’s compression and tensile resistance stamina are extremely reduced in contrast to you to from the state-of-the-art rock formations, nearly minimal. During the time, new weak interlayer can become the overflow channel of your detonation gasoline and you will deteriorate the fresh smashing and you may putting aftereffect of new high-tension energy generated by the latest burst. As well, in the example of highest hard rock in place of burst cracks, it is difficult to crack sizeable free dating sites in Jacksonville rocks making use of the second smashing concept of block rock accident throughout the throwing procedure due so you can a deep failing interlayer 26 . Ergo, new section off soft rock and difficult rock is an essential step of build approach.

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.