Wave propagation, damage evolution, and dynamic fracture extension. Part II. Blasting

Roßmanith, H. P.; Knasmillner, R. E.; Daehnke, A.; Mishnaevsky, Leon

doi:10.1007/bf02538964

Cited by 33 publications

(20 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In laboratory experiments, the fracture patterns in PMMA are qualitatively very similar to the fracture patterns in rock but different in scale which is believed to be useful in investigating the fracturing mechanism (Kutter and Fairhurst 1971). (Rossmanith et al 1996) used a 3D cube-type laboratory models fabricated from PMMA, transparent enough to be observed, to undertake dynamic loading from explosives (Rossmanith et al 1996). Fig.…”

Section: Blasting and Impactsmentioning

confidence: 99%

High-Speed Photography and Digital Optical Measurement Techniques for Geomaterials: Fundamentals and Applications

et al. 2017

View full text Add to dashboard Cite

Geomaterials (i.e., rock, sand, soil and concrete) are increasingly being encountered and used in extreme environments, in terms of the pressure magnitude and the loading rate. Advancing the understanding of the mechanical response of materials to impact loading relies heavily on having suitable high-speed diagnostics. One such diagnostic is high-speed photography, which combined with a variety of digital optical measurement techniques can provide detailed insights into phenomena including fracture, impact, fragmentation and penetration in geological materials. This review begins with a brief history of high-speed imaging. Section 2 discusses of the current state-of-the-art of high-speed cameras, which includes a comparison between Charge-Coupled Device (CCD) and Complementary Metal-Oxide-Semiconductor (CMOS) sensors. The application of high-speed photography to geomechanical experiments is summarized in Section 3. Section 4 is concerned with digital optical measurement techniques including photoelastic coating, Moiré, caustics, holographic interferometry (HI), particle image velocimetry (PIV), digital image correlation (DIC) and infrared thermography (IRT), in combination with highspeed photography to capture transient phenomena. The last section provides a brief summary and discussion of future directions in the field.

show abstract

Section: Blasting and Impactsmentioning

confidence: 99%

High-Speed Photography and Digital Optical Measurement Techniques for Geomaterials: Fundamentals and Applications

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Kutter and Fairhurst [10] explored the effects of explosion stress waves and explosive gas on crack propagation to find that blast-induced cracks extend toward the direction of the maximum principal stress in the static stress field. Rossmanith et al [11] studied the dynamic evolution of three-dimensional cracks under a combination of blasting and uniaxial stress; they gathered valuable physical and mechanical information regarding crack propagation under blasting loading which can be utilized for numerical simulations. Liu et al [12] conducted a photoelastic experiment to observe the propagation mechanism of the explosion stress wave under an initial stress condition.…”

Section: Introductionmentioning

confidence: 99%

In Situ Stress Effects on Smooth Blasting: Model Test and Analysis

Yang

Fang

Yang

et al. 2020

Shock and Vibration

View full text Add to dashboard Cite

Most of the roadway excavation is completed by the drilling and blasting method. With the increase of buried depth, the existence of ground stress will generate a significant impact on the rock blasting, especially on the smooth blasting. In this study, self-made homogeneous similar materials and digital image correlation methods were used to determine influence of ground stress on the smooth blasting under uniform explosive charge parameters and various in situ stress conditions. The results show that the crack outline after blasting changes from zigzag to straight in shape, and multifractal calculation results of the rupture section between blastholes show that the fracture surface becomes flatter as ground stress increases, which is conducive to roadway formation. The strain and equivalent strain rate obviously decrease as the distance between the blasthole and measuring points increases. The same trend occurs as the confining pressure goes up. Meanwhile, a postexplosion acoustic wave test indicates that confining pressure inhibits damage of the retained rock, which is consistent with strain and equivalent strain rate results. Finally, we discussed the crack propagation mechanism of rock in smooth blasting.

show abstract

“…e obtained cracks in the experiment demonstrated that the crack propagation aligns with the direction of applied static stress, and some of the cracks, which initiated in a radial direction other than that of the static stress field, eventually curved off into the direction of the applied pressure. Rossmanith et al [8] investigated the fracturing mechanism under dynamic-static loading with explosion and preloaded pressure on three-dimensional cube-type rock-like material (polymethyl methacrylate), and the test results showed that the fracture preferentially propagates in the direction of the major principal stress. Yang et al [9] researched the mechanism of rock crack propagation under static stress and blast loading by means of caustics experiment, and the results indicated that the preloaded pressure which is vertical to the direction of crack propagation reduces the stress intensity factor at the crack tip and thus suppresses the propagation of cracks.…”

Section: Introductionmentioning

confidence: 99%

Study of the Rock Crack Propagation Induced by Blasting with a Decoupled Charge under High In Situ Stress

Liu

Yang

2020

Advances in Civil Engineering

View full text Add to dashboard Cite

The high in situ stress can significantly affect the blast-induced rock fragmentation and cause difficulties in deep mining and civil engineering where the drilling and blasting technique is applied. In this study, the rock crack propagation induced by blasting under in situ stress is first analyzed theoretically, and then a numerical model with a decoupled charge in LS-DYNA is developed to reveal how the initiation and propagation of rock cracks are under high in situ stress. Through simulation, the mechanisms of blast-induced crack evolution under various hydrostatic pressures and nonhydrostatic pressures are investigated, and the differences in crack evolution with specific decoupling coefficients are compared. According to the simulation, three damage zones, i.e., the crushed zone, the nonlinear fracture zone, and the radial crack propagation zone, are formed, and the radial crack evolution is greatly suppressed by the high in situ stress which has no much influence on the crack propagation in the crushed and the nonlinear fracture zones. The velocity of crack propagation is slightly reduced, and the process of crack propagation is stopped early when the rock is subjected to high in situ stress. Furthermore, the numerical analysis indicates that the crack grows preferentially in the direction of maximum principal stress, and the radial crack propagation is predominantly controlled by the preloaded pressure, which is vertical to the crack propagation direction. Based on the numerical results, it is suggested that the optimal decoupling coefficients for rock cracking are 2.65, 1.87, 1.37, and 1.22 for 0, 10, 20, and 30 MPa, respectively. This study provides not only an analysis of the rock crack evolution under high in situ stress but also a reference for resolving excavation difficulties in deep mining.

show abstract

Wave propagation, damage evolution, and dynamic fracture extension. Part II. Blasting

Cited by 33 publications

References 7 publications

High-Speed Photography and Digital Optical Measurement Techniques for Geomaterials: Fundamentals and Applications

High-Speed Photography and Digital Optical Measurement Techniques for Geomaterials: Fundamentals and Applications

In Situ Stress Effects on Smooth Blasting: Model Test and Analysis

Study of the Rock Crack Propagation Induced by Blasting with a Decoupled Charge under High In Situ Stress

Contact Info

Product

Resources

About