Method according to particular lithology distribution
Undergoing stone blasting, the new bodily and you may physical features of one’s material is seriously that of fundamental things you to definitely determine the end result out of material blasting 21 female escort Roseville CA . You will find commonly an unclear comprehending that the brand new more difficult brand new stone, the brand new harder it’s to get blasted in the modern technology community. Although not, the blasting impression isn’t just as expected in technologies methods. As an alternative, it is often found that the newest hardness from rock isn’t higher as device usage of explosives is actually high twenty two .
With respect to the cracking method from material blasting 23 , the energy put out of the explosives serves towards stones from the wonder trend and you will expansion pressure of detonation gasoline when a volatile explodes to your stones. A perfect destruction off rocks is a result of the action fret developed by brand new rush surpassing its power maximum, and this demonstrates the newest smashing condition are directly linked to new burst opportunity together with technical services of the rock. Put differently, within the certain standards from equipment explosive consumption form, particular, and you can 100 % free facial skin, the charges amounts is mostly dependent on the newest mechanical characteristics away from stone to attain a specific crushing impression. Thus, new lithology distribution is the number one reason for determining the latest equipment consumption of explosives 24 .
In an out in-breadth study of the brand new lithology off hard-rock, it is learned that highest be concerned keeps a life threatening influence on the new blasting procedure and you can material cracking feeling. The outcome including show that highest-website worry unloading and you can blasting loading aren’t two independent procedure, on the other hand, they work within the collaboration, additionally the dynamic handling has a serious impact twenty five . Ergo, brand new distribution regarding hard-rock is key to your design regarding a beneficial segmented charge getting blasthole.
Collection away from blasthole stone strata
On the old-fashioned blasting techniques, the lithology change over the blast opening breadth isn’t considered regarding the blasting construction. Thus, just one costs build is then followed. About superimposed rock bulk that have smooth and difficult inclusions, the fresh new poor interlayer’s compression and you may tensile resistance power are reduced compared with you to definitely regarding advanced rock structures, almost minimal. At the time, this new weak interlayer can easily become the flood station of the detonation gasoline and weaken the fresh crushing and you may putting aftereffect of the latest high-tension gas made by the rush. On the other hand, when it comes to large hard-rock instead explosion breaks, it is difficult to crack sizeable rocks by using the secondary crushing principle out of stop rock collision on putting process owed to a weak interlayer twenty-six . Hence, this new section away from soft rock and hard stone is an essential step of construction 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, Rs means the thickness of soft rock, and Rh means the thickness of hard rock.