Traditional presplit blasting is the simplest form of presplit blasting, and it involves drilling a row of parallel holes along the intended presplit line. The holes are then loaded with …
• Hydraulic blasting has been explored in other areas such as small scale dimension cutting in quarries and oversize blasting • Water will also wedge into the radial fractures generated in the surrounding rock during detonation, amplifying fracture propagation • The use of water coupled blasting in an underground presplit application
Optimal Design of Presplit Blasting Network of Deep Concave Open-Pit Mine Slope with Heterogeneous Complex Rock Mass Yajun Chen1, Juanjuan Zhao1 2and De Cao 1 College of Mining Engineering and Geology, Xinjiang Institute of Engineering, Urumqi 830091, China 2 Beishan Open-Pit Coal Mine, Qitai County Changji Prefecture Xinjiang 831800 …
Pre-splitting is a controlled blasting technique with applications in open pit mines. The main objectives of pre-splitting in open pit mining are: preventing/controlling back-break; controlling ...
Presplit blasting is a commonly used technique for contour excavation that offers the advantages of eliminating overbreak and underbreak, minimizing damage to the remaining rock and reducing disturbance induced by subsequent blasts on adjacent structures. In recent years, presplit blasting has been increasingly used in rock …
To evaluate the effect of using presplit blasting technique in weakening the hard overlying strata, the breakage of the hard overlying strata and the inner structures …
smooth blasting and presplit blasting excavation methods are widely used in the contour excavation of high rock slope. The excavation sequence of these two methods is illustrated in Fig. 2. (The ...
Blasting is a major method of excavation in mining, civil construction and infrastructure projects. The integrity of the rockmass of the final wall after excavation is important for the stability and economics of the operation. Perimeter blasting achieves a planned surface of the rockmass. The pre-split is one such technique, deployed when …
Owing to the combination of blasting load and stress redistribution, crack formation at the lateral sides was inhibited during presplit blasting, while the middle side could not be sufficiently ...
Figure 5.3: Comparison between Presplit and Regular Blasting. Hoek (2007) Mechanics of Smooth and Presplit Blasting. In order to better understand how smooth and presplit blasting affect the final face, one needs to know the mechanisms utlized. Some of this was previously explained in the crack formation, but this can be …
blasting is always larger than that based on presplit blasting at the same distance and direction, whether main or pe-ripheral boreholes. In addition, PF from both main and peripheral boreholes based on smooth blasting decreases gradually with the increases of distances, but PF from main boreholes based on presplit blasting rstly decreases and
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-stress. In this study, the influences of ...
Proper presplitting reduces the necessary scaling of benches to 10% of previous presplitting numbers. It increased productivity in construction blasting by more …
Directional presplit blasting (DPB) technology for an innovative no-pillar mining approach is introduced. First, a mechanical model is established to analyze crack initiation and coalescence using the new technology. The explosion pressure formula containing tress concentration factor explains the relationship between the quantity of …
Presplit blasting has been adopted to protect final rock faces to ensure wall stability and protect structures against blast damage. According to Phifer et al. (2012), presplitting is an old but ...
The detection and research results of blast vibration show that presplit blasting can reduce the attenuation coefficient of stress wave by half, and the vibration absorption ratio could reach 50.2 ...
Presplit blasting can reduce vibration and back impact induced by cast blasting, thus resulting in a smooth bench slope. To design reasonable presplit blasting parameters, this research investigated the formation of presplit faces based on the explosion mechanics and revealed the cracking mechanism of presplit blasting. …
• ITS DEVELOPMENT in 1958, presplit blasting has become an accepted method of obtaining essentially smooth, vertical walls in rock excavation. The usual technique …
In presplit blasting, rock fracturing is the product of the synergistic action of stress waves and detonation gas. The study found that the presence of empty holes between blast holes can improve tangential stress distribution and guide crack propagation. The characteristic zones of crack initiation, propagation, and interconnection were ...
The effectiveness of the presplit blasting technique was well verified when the microstructures of the surrounding rock were investigated. The success presented in this paper does not only ...
To understand differences of smooth and presplit blasting for the excavation of rock wells, two field experiments using these two techniques are implemented at the same test site, respectively.
For the presplit blasting, the final damage of rock slope is mainly induced by presplit blasting itself. The spatial distribution characteristics of the final damage zone of two methods are compared. Two classes of damage zone could be found in smooth blasting excavation; one of them is the columnar high-degree damage zone around the …
presplit blasting at the same monitoring distance and di-rection.Forexample,whenthemonitoringdistanceis50m, the dominant frequency from peripheral boreholes in the
Presplit blasting results cannot be evaluated until the bench excavation is separated from the presplit line. Singh et al. [14] and Uysal and Cavus [15] also highlighted that the drill pattern is a critical part of blast design and is related to borehole diameter, explosive energy, bench geometry, and rock ...
Presplitting involves drilling a row of blastholes along the excavation contour and detonating them before the other holes in a blasting sequence. The …
Presplit blasting can reduce vibration and back impact induced by cast blasting, thus resulting in a smooth bench slope. To design reasonable presplit blasting parameters, this research ...
DOI: 10.1007/s00603-024-03877-8 Corpus ID: 269152429; Investigation on Rock Fracturing in Presplit Blasting Under Various Initial Stresses @article{Liu2024InvestigationOR, title={Investigation on Rock Fracturing in Presplit Blasting Under Various Initial Stresses}, author={Ke-wei Liu and Xu-dong Li and Linqi …
To ensure that the mining steps of deep concave open-pit coal mines with heterogeneous complex rock masses in arid areas are safely bounded by the design requirements and form a fixed side wall ...
Advances in controlled blasting look to improve blasting efficiency and reduce overbreak, with the end product a smooth, stable rock surface with high contour …
1. Introduction. Controlled blasting, such as smoothwall and presplit blasting, is widely adopted in tunnel perimeter excavation and plays a significant role in reducing underbreak/overbreak and the extent of excavated damage zone, which controls the integrity and stability of excavated tunnel contour [1], [2], [3].In recent decades, …
Presplit blasting is commonly practiced in open pit mines to create shear planes on in situ rock slope to ensure pit wall stability, and also protect nearby structures against blast damage ...
The shortcoming of conventional smooth blasting in damaging inevitably to remaining rock is pointed out, and it is presented that the application of the directional-split blasting technique is an ...
In this study, to synthetically reveal the differences of presplit and smooth blasting, blast-induced vibrations and excavation qualities of rock wells based on two control …
