Failure Mechanism and Effect of Nozzle Parameters on Abrasive Water Jet Rock Breaking

Abrasive Water Jet (AWJ) technology has vast application prospects in the assisted drill-blasting of tunnel excavation, with the advantages of fast-breaking speed, low tool wear, less dust, and good mobility. Nevertheless, AWJ technology has some limitations and shortcomings, such as the small effective fracturing range and parameter mismatch, which influence the fracturing effect of AWJ. To solve the abovementioned issues, it is necessary to study the failure mechanism of rock impacted by AWJ and nozzle parameter effects on rock fragmentation. Based on the coupling algorithm of Smooth Particle Hydrodynamics and Finite Element Method (SPH-FEM), in this research, the numerical model of AWJ impacting rock was established, and the result was verified with Computed Tomography (CT) scanning after the AWJ impacting rock experiment and image processing technology. Through the analysis of the stress characteristics of typical particles in the rock model at different stages and positions, the formation and expansion mechanisms of the crater and the cracks were revealed. Additionally, in this research, the comprehensive damage factor of rock (X) representing the fragmentation degree was defined. By comparatively analyzing X-values with certain technical parameters of AWJ, the importance ranking of the nozzle parameters, the effect of each nozzle parameter on the rock fragmentation, and the optimal parameter combination were also investigated.

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Experimental Investigation of Hard Rock Breaking Using a Conical Pick Assisted by Abrasive Water Jet

Rock Mechanics and Rock Engineering ◽

10.1007/s00603-020-02168-2 ◽

2020 ◽

Vol 53 (9) ◽

pp. 4221-4230 ◽

Cited By ~ 1

Author(s):

Songyong Liu ◽

Fangyue Zhou ◽

Hongsheng Li ◽

Yueqiang Chen ◽

Fengchao Wang ◽

...

Keyword(s):

Experimental Investigation ◽

Hard Rock ◽

Rock Breaking ◽

Water Jet ◽

Abrasive Water Jet ◽

Conical Pick

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Numerical research on rock breaking by abrasive water jet-pick under confining pressure

International Journal of Rock Mechanics and Mining Sciences ◽

10.1016/j.ijrmms.2019.06.007 ◽

2019 ◽

Vol 120 ◽

pp. 41-49 ◽

Cited By ~ 6

Author(s):

Songyong Liu ◽

Yuming Cui ◽

Yueqiang Chen ◽

Chuwen Guo

Keyword(s):

Confining Pressure ◽

Rock Breaking ◽

Water Jet ◽

Abrasive Water Jet ◽

Numerical Research

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Experimental Study on the Dynamic Rock-Breaking Performance of Pulsed Abrasive Jet Drilling Method

Shock and Vibration ◽

10.1155/2020/8872919 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

Yukun Du ◽

Xiaohong Chen ◽

Bo Zhao ◽

Zhiyuan Huang ◽

Meilian Wu ◽

...

Keyword(s):

Energy Demand ◽

Oil And Gas ◽

High Efficiency ◽

High Strength ◽

Rock Breaking ◽

Water Jet ◽

Abrasive Water Jet ◽

Drilling Tool ◽

Tight Sand Gas ◽

Better Than

The efficient development of deep oil and gas reservoirs with abundant resources is conducive to meet the growing energy demand. However, it is very difficult to drill in the deep reservoirs such as tight sand gas and shale gas because of their high strength, low porosity, and low permeability. In this study, it is pointed out that developing high-efficiency drilling methods based on new combined water jets is a good approach to promote the rate of penetration (ROP) in such tight deep reservoirs. A pulsed abrasive water jet drilling tool is designed, and its dynamic work principle is analyzed. The hydraulic structure is optimized; meanwhile, the rock-breaking experiments of this structure are carried out. The results show that the rock-breaking performance of the pulsed water jet is much better than that of the continuous water jet. It is also found that the rock-breaking performance of the pulsed abrasive water jet is much better than that of the premixed abrasive water jet. In addition, the best rock-breaking standoff distance, abrasive concentration, and particle size are detected.

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Optimization of the Cutting Process of Wood-Based Agglomerated Materials by Abrasive Water-Jet

Acta Silvatica et Lignaria Hungarica ◽

10.2478/aslh-2014-0003 ◽

2014 ◽

Vol 10 (1) ◽

pp. 31-47 ◽

Cited By ~ 1

Author(s):

Monika Kvietková ◽

Štefan Barcík ◽

Miroslav Gašparík

Keyword(s):

Opposite Effect ◽

Longitudinal Direction ◽

Water Jet ◽

Kerf Width ◽

Feed Speed ◽

Abrasive Water Jet ◽

Entry And Exit ◽

Technical Parameters ◽

Water Jet Cutting ◽

Cutting Direction

Abstract This paper deals with the cutting MDF, OSB, and plywood boards by abrasive water-jet (GMA Garnet Australian, grain size 80, MESH = 0.188 mm), with a kerf width depending on the material properties and technical parameters (material thickness, cutting direction, abrasive flow, and feed speed). The entry of water-jet cutting in the longitudinal direction produces changes in the material due to lateral leads spreading the width of the cut joints by an average of 0.20 mm for MDF boards, 0.3 mm for OSB boards, and 0.17 mm for plywood. On the exit side of the material, the water has the opposite effect. In relation to the thicknesses of the material, the width of the cut joints increases. The experiment has shown that the optimum value of the feed speed is explicitly 400 mm.min-1, at which the kerf width reaches the lowest dimensions both at entry and exit, and the abrasive flow of 450 g.min-1 has been shown as optimum.

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Fragmentation Pattern and Removal Mechanism of Concrete Subjected to Abrasive Water Jet Impact

Advances in Materials Science and Engineering ◽

10.1155/2021/6618386 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Jialiang Liu ◽

Yujie Zhu ◽

Yongzhi Xue ◽

Hao Sun

Keyword(s):

Transition Zone ◽

Pure Water ◽

Ct Scanning ◽

Water Jet ◽

Fragmentation Pattern ◽

Abrasive Water Jet ◽

Removal Mechanism ◽

Jet Impact ◽

Propagation Law ◽

The Impact

Abrasive water jet (AWJ) breaking technology is suitable for the maintenance and repair of concrete structures, generating minimal dust, low tool wear, and no vibrations or selective destruction. The failure features and mechanisms of concrete subjected to AWJ impact are fundamental issues of AWJ breaking technology, which are also related to the safety and quality of engineering construction. Based on computed tomography (CT), scanning electron microscopy (SEM), and image processing technology, this paper studied the fragmentation pattern and removal mechanism of concrete under AWJ impact. The general failure characteristics and crack propagation law of concrete subjected to AWJ impact were described through AWJ impact concrete tests. The spatial distribution of damage in concrete subjected to AWJ impact can be divided into the intensive action zone, the transition zone, and the weak action zone. The removal mechanism of AWJ was discussed by comparing the impact performance of a pure water jet (PWJ) system. The results indicate that abrasive particles can cause cliff-shaped fracture and lip-shaped distortion in the aggregate part and flat fracture surface in the matrix part. There is no obvious crack in the interfacial transition zone (ITZ) due to the weakening of the water wedge effect.

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