In Rock Fragmentation by Blasting: The 10th International Symposium on Rock Fragmentation by Blasting, 2012 (Fragblast 10) 2013, pp. 707-714. The …
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Jaya Batu Sdn Bhd is a leading quarry and mining contractor in Malaysia. Our mission is to provide world-class services to our clients, such as drilling, blasting, loading, hauling and crushing operation. Our team of professionals has more than 20 years of experience in the industry and we are growing stronger than ever.
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A hard and massive roof (HMR), which can also be called a massive and strong roof. This, refers to the strong, thick, high rock strength, integrated, and flawless seam that do not collapse within a short period of time [1,2,3,4].Owing to the significant variability of hard roof conditions in China, the thickness of such roofs varies from tens to hundreds of meters.
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The 2D distinct element code was used for simulation of presplitting in a rock slope. The blast load history as a function of time applied to the inner wall of each blasthole. Important parameters ...
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Most of the blasting techniques in common use for highway rock excavation are designed to ensure optimum fragmentation and rarely consider the effect of blast disturbance on the stability of the design slope.
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Controlled blasting techniques are used to control overbreak and to aid in the stability of the remaining rock formation. The less competent the rock mass itself, the more care has to be taken in avoiding damage. Presplitting is one of the most common methods which is used in many open pit minings and surface blast designs. The …
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Blast tests show that the number and length of blast-created fractures in presplitting decrease with increasing static stress, and thus, presplit crack formation gradually fails, producing a rock ...
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As can be seen from Figure 10, the presplit blasting destroyed the rock mass around the blast hole, resulting in the formation of a plastic failure zone around the blast hole. The rock mass inside the area was loosely broken, the bearing capacity was weakened, and a local stress drop was observed.
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Blasting and rock fragmentation depend on two groups of variables. The first group consists of mass properties, which are uncontrollable, and the second one is the drill-and-blast design parameters, which can be controlled and optimized. ... and filtering the effects of explosive gases from production blasting. Presplitting in open pit mining ...
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Jaya Batu Sdn Bhd is a leading quarry and mining contractor in Malaysia. Our mission is to provide world-class services to our clients, such as drilling, blasting, loading, hauling …
WhatsApp: +86 18221755073
The 2D distinct element code was used for simulation of presplitting in a rock slope. The blast load history as a function of time applied to the inner wall of each blasthole. Important parameters ...
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surrounding rock strength of the €oor strata in the 72909 ventilation roadway. Compared with the method of testing the strength of rock samples in laboratory, the borehole penetrating method can measure not only the rock strength of di™erent depths in €oor strata but also the rock layers containing structural planes, such as joints and cracks
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ABSTRACT. ABSTRACTInvestigations by the authors during surface and underground excavations indicated that the success of presplitting and smooth blasting was largely depended on the nature and orientation of joints and bedding planes in the rock mass. The paper describes the results obtained when the above two techniques were experimented …
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Rock breakage and fragmentation by drilling and blasting have been widely used for foundation excavation in projects of hydropower station, nuclear power plant, municipal engineering, and subgrade ...
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Coupling Technology of Deep-Hole Presplitting Blasting and Hydraulic Fracturing Enhance Permeability Technology in Low-Permeability and Gas Outburst Coal Seam: A Case Study in the No. 8 Mine of Pingdingshan, China. ... Observing the rock formation area around the roadway, it can be found that, except for the area close to the …
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Uniblastcon Sdn Bhd was established in year 1996 (Formerly under Uniblast Contractor). We are specialist in using explosives for open and control blasting in rock excavation. We had more than 20 years …
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A Proper Presplit Creates a Safer Working Environment While Reducing Costs. By Anthony J. Konya and Calvin J. Konya Geology is often blamed for poor blast …
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Precision Presplit Blasting is a controlled blasting procedure that is used to produce a shear plane within a weak rock or one that is geologically complicated with the minimum amount of explosive and minimum overbreak. Used to produce a clean, relatively solid rock cut face where rock is weak, or rock has extensive geologic discontinuities such as …
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The strictness of the result of an excavation, whether mechanical or by means of explosives, is naturally conditioned by its objective and, therefore, by the type of technique applied to achieve it. To attain the best results in terms of rock breakage, and with respect to the final profile, it is important to evaluate the specific excavation energy and its …
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Abstract. When the presplit blasting is applied to rock excavation at a deep level, crack-forming difficulties are encountered due to the characteristics of high geo …
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Conference: Modeling Explosive/Rock Interaction During Presplitting Using ALE Computational Methods ... ALEGRA has been applied to a 2-D simulation of presplitting using decoupled explosives in rock blasting with very interesting results. The detonation of the explosive at the bottom of the hole sends a shock wave up the …
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The positive effects of deep hole presplitting blasting permeability enhancement technology on the pressure relief and permeability enhancement of a low pressure and high gas coal seam were ...
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In fact, in controlled blasting such as presplitting and smoothwall blasting, lightly radial charged hole is widely adopted for the creation of smooth excavation perimeter (Hu et al., 2014(Hu et ...
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Other articles where presplitting is discussed: tunnels and underground excavations: Sound-wall blasting: …met by the technique of presplitting, developed in the United States in the late 1950s. Basically, this technique consists of creating a continuous crack (or presplit) at a desired finished excavation line by initially firing a line of closely spaced, …
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Fig. 1 depicts the two-holes analytical model of presplit blasting. The hole spacing is S.Two split-holes share the same hole diameter d b and explosive diameter d ch, which are in in-situ stress field.The angle α between the orientation of major principal stress and the centreline of two holes ranges from 0° to 90°. The dynamic and static tangential …
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Pre-splitting can be defined as 'a technique using lightly charged, closely spaced holes to induce a fracture plane along a required design profile, which isolates the rock to be blasted from the surrounding rock mass'. The holes are generally fired …
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Hu et al. investigated the blast-induced rock damage process with presplit and smooth blasting techniques during the excavation of high rock slope. The results demonstrated that when smooth blasting was applied, the damage zones were induced by the explosives of all boreholes, but when presplit blasting was used, damage zones were only induced ...
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Abstract This paper focuses on the comparison of damage induced by smooth blasting and presplit blasting based on the excavation of high rock slope. The whole damage process of the smooth blasting and presplit blasting excavation method is studied by using a cumulative blasting damage numerical simulation technology based on the …
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In rock blasting modelling, it is extremely important to select a constitutive material model for rock (Cheng et al. 2021a;Li et al. 2021;Liu et al. 2020). ... presplitting blasting the roof ...
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Pre-splitting blast at a Coal Mine ERG Industrial. Safety & Wall Stability. Ensuring stable high walls is of utmost importance in any project, be it open-pit mines, quarries, or civil engineering endeavours. Pre-splitting is a technique used to establish a secure boundary between the blasted material and intact rock.
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