Abrasive blasting is a common process for cleaning or roughening the surface of a material prior to the application of a coating. Although the process has been in practice for
With the shift of coal seam mining to the deep, the in-situ stress of coal and rock mass increases gradually. High ground stress can limit the generation of rock cracks caused by blasting, and ...
Request PDF | Experimental Study and Mechanism Analysis on the Effects of Biaxial In-Situ Stress on Hard Rock Blasting | Drill and blast method is widely applied in deep rock engineering, and the ...
Whether you are dealing with hardened fly ash, popcorn ash (LPA), or MgO plugging, results continually show the catalyst to be effectively cleared of chemical and physical deactivation substances, a decrease in pressure drop, increase in reaction surface, decrease in ammonia slip and increased plant efficiency.
This implies that rock fragmentation in surface blasting is more dependent on delay time than that in underground blasting. Download: Download high-res image (523KB) Download: Download full-size image; Fig. 17. Effect of in-situ stress on fragment size at passing fractions of x 10, x 50 and x 80. 5.
blasting operations in surface min-ing is rock fragmentation. Drilling. and blasting are the two key compo-nents in the overall rock fragmenta-tion system — the first element of the.
In deep rock engineering, the conventional drilling and blasting method remains popular for rock excavation, and decoupled charging with various coupling mediums (e.g., air, sand, drill cuttings ...
In deep mining, the rock mass is characterized by high in-situ stress, which makes the traditional drilling and blasting methods difficult, inefficient, and costly. To overcome this difficulty, LS-DYNA software was used to simulate the process of fan-hole blasting under in-situ stress. The blasting design was carried out for a 932.5 m depth of rock mass in combination …
The blasting design considers conventional tunnel excavation, with a peak load of 1620 MPa, a rise time (t r) of 0.5 ms, a decay time (t d) of 4.5 ms, and a total positive pressure duration of 5 ms. The blasting time-history curve is depicted in Fig. 7.
free surface (Figure 1). As the explosive source can be considered as a point explosive, the resistance line is approximately equal to the hole depth in this test. In order to study the influence of in-situ stress ... blasting under different length of resistance lines. Then a 3D theoretical model considering stress ...
Abrasive blasting is a common process for cleaning or roughening the surface of a material prior to the application of a coating. Although the process has been in practice for over 100 years, …
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. ... By this, presplit-cracks can be taken as a protection strip, which keeps the final excavation surface (steep slope and the like) self-stable with less maintenance (Hu et al ...
For the blasting excavation of deep-buried tunnel, the blasthole parameters obtained by the improved tensile and compressive strength criteria can ameliorate the under-excavation phenomenon caused by in-situ stress and enhance the blasting quality. ... The new free surface may change the minimum burden of the latter detonated blastholes and ...
In complex high in-situ stress conditions, how to achieve the ideal rock blasting effect through effective methods is often a difficult point of blasting operations. This paper …
Semantic Scholar extracted view of "Study of presplit blasting under high in-situ stress" by Xu-dong Li et al. ... Fracture behavior and fracture surface smoothness of rock-like model subjected to axial decoupling spherical charging. Tao Hu Xianglong Li Jianguo Wang Jun Ma Qiwen Hu Ting Zuo. Engineering, Geology.
A lot of research has been done in the area of crack initiation and propagation due to blasting in the presence of confining stresses. Field tests conducted by Nicholls et al. [8] indicated that it is much easier to presplit in the direction of the maximum in situ compressive stress than at any angle to this direction. Blast-induced dynamic fracture tests with additional …
With over 15 years of experience, GNC offers premier coating & blasting services for industrial and oilfield companies looking to improve the appearance and the quality of their equipment. We offer services throughout Texas and the Gulf Coast Region. ... Guaranteed to meet the required surface profile with a wide-assortment of media grade or size;
Abrasive Blasting with Post-Process and In-Situ Characterization Robert Jeffrey Mills Thesis submitted to the faculty of the ia Polytechnic Institute and State University in partial …
Suggestions to optimize DHPB in coal mines are proposed in terms of in-situ stress, blasthole inclination angle, blasthole spacing, and verified by field tests. Effect of three …
Figure 2. Halo nozzles surround the abrasive blast with a curtain of water, dampening dust after impact. With water introduced into the blast stream at the nozzle, the abrasive stream velocity is reduced before it impacts the …
prevent the eect of reected stress at the free surface on the blasting eect of the rock mass. e exible bound-ary theory is as follows. When the explosive explosion, the relationship between the ...
Drill and blast method is widely applied in deep rock engineering, and the in-situ stress poses a great challenge to blasting excavation. The failure mechanism of rock under coupled dynamic and ...
insitu. is a measure of the mean size of in situ blocks formed by the rock mass. ... analysis of SLC ring blasting data and a number of experiences from surface blasting. Currently, the breakage ...
The uncontrollable parameters are geological discontinuities, insitu stresses, ground condition, surface topography etc. . Over the years, researchers have proposed various empirical predictive models for predicting PPV. ... Most of the available predictor equations and soft computing techniques have been used for predicting PPV in the surface ...
In this approach, an innovative approach to the assessment of in-situ blasting is proposed and evaluated. This approach focuses on the acceptability of rock fragments on the …
Many researchers have investigated the damage evolution mechanisms of rock under blasting loads (Deng et al., 2014, Li et al., 2013, Li et al., 2014, Mitelman and Elmo, 2016, Zhu et al., 2010).However, little work has been done on such mechanisms for deep rock masses under the cut blasting method (Bäckblom and Martin, 1999, Chen et al., 2007, Cunningham …
The effect of in-situ stresses on the fracturing of rock due to blasting was investigated. A theoretical model was used to explain the effect mechanism of in-situ stresses …
an alternative to drilling and blasting in both underground and surface mines. India's commitment to self-reliance in ... Insitu p-wave velocity, presence of joints/discontinuities, dirt bands/intrusions and ash/impurities/silica content, etc. Machine parameters include engine power, cutter power, pick the lacing pattern, ...
In this study, a single-hole blasting model based on the open FDEM suite, OpenFDEM (https://), is built to uncover the mechanism of blast-induced fracture propagation and damage zone under high in-situ stress, addressing the challenges of over-excavation and under-excavation in deep tunnel blasting excavation.The effects of …
In any surface mine, blasting operation plays a vital . role. In surface mining where blasting is used for . excavation, the overall cost effectiveness of the .
Presplit blasting is a commonly used technique for contour excavation that offers the advantages of eliminating overbreak and underbreak, minimizing damage to the remaining …
To prevent the effect of reflected stress at the free surface on the blasting effect, it is crucial to utilize a transmissive flexible boundary. For this purpose scholars have proposed the dispersion
When the drill and blast (D&B) method is adopted in rock excavation at great depths, cut blasting becomes difficult because of high in-situ stress influences (Xie et al., 2016). Cut blasting is important in developing a free surface for subsequent blasting, and influences the overall blasting procedure (Zhao et al., 2011).
Surface modification of C/C composites by blasting treatment and in-situ grown SiC nanowires was proposed to improve the thermal cycling performance of Si-Mo-Cr coating. Compared with the coated C/C composites with blasting treatment only, the bonding strength between Si-Mo-Cr coating and C/C substrate was increased by 5.7% due to the ...
reflection tensile failure of the joint surface was weaker than that without filling. The coupling between the tensile crack generated by the reflection tensile action of the joint surface and the blasting main crack enhanced the fracture degree of the rock mass between the explosion source and the joint.