Size effects on the strength and cracking behavior of flawed rocks under uniaxial compression: from laboratory scale to field scale

Choo, Jinhyun; Sun, Yuan; Fei, Fan

doi:10.1007/s11440-023-01806-7

Cited by 14 publications

(3 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(2) When the wing crack extended near the short axis of the elliptical pre-existing crack, spiral cracks appeared and extended downward to the surface of the specimen. (3) When the axial load approached the failure load, secondary cracks appeared and propagated instantaneously to the surface of the specimen. ( 4)…”

Section: Data Availability Statementmentioning

confidence: 99%

“…Mostafa Asadizadeh et al [2] performed numerical simulations on cylindrical specimens with cracks under axial load and studied the effects of the inclination, length, and aperture of individual fractures on the mechanical behavior of the rock mass, crack initiation, and propagation. Jinhyun Choo et al [3] studied the influence of size effects on the strength and crack propagation mode of gypsum samples with single and double defects through experiments and numerical simulations. Hadi Haeri et al [4] studied an L-shaped notch specimen using the Brazilian test, biaxial test, and numerical simulation and revealed the influence of the distance between two L-shaped fractures, the crack length, and angle on the failure mode, crack type, and strength of the specimen.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Micro-Evolution Mechanism of 3D Crack Initiation in Brittle Materials with Hole under Uniaxial Compression

Maimaitiyusupu,

Zhu,

Ren

et al. 2024

Materials

View full text Add to dashboard Cite

This article investigates the microscopic mechanism of crack initiation and propagation in three-dimensional embedded cracks in brittle materials containing circular holes. First, a method for the development of transparent, brittle materials is proposed. Second, UCS tests were conducted on transparent, brittle materials containing circular holes and internally embedded three-dimensional cracks. Finally, a numerical model was established in PFC3D to analyze the crack initiation and propagation mechanism. The results show that when α = 0° (α refers to the pre-existing crack inclination), the upper tip of the pre-existing crack appears as a tensile wing crack, and the lower tip of the pre-existing crack appears as a tensile–shear mixed crack. When α = 30°, no wing crack appears, and the tensile crack on the fracture surface only appears after the hole cracks. When α = 60 and 90°, a tensile wing crack and an anti-wing tensile–shear mixed crack appear at the upper tip of the pre-existing crack. A tensile wing crack appears at the lower tip of the pre-existing crack and appears “self-limiting”. During the propagation of wing cracks to the surface of the specimen, the transition sequence of the crack propagation mechanism is tensile through failure—tension-shear mixed failure—tensile failure. It can be seen that the interaction between the crack and hole has an important influence on the evolution mechanism of the crack and the failure mode of the specimen.

show abstract

Section: Data Availability Statementmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of Micro-Evolution Mechanism of 3D Crack Initiation in Brittle Materials with Hole under Uniaxial Compression

Maimaitiyusupu,

Zhu,

Ren

et al. 2024

Materials

View full text Add to dashboard Cite

show abstract

“…In the numerical simulation, the Mises stresses are compared with the dynamic compressive and tensile strengths to determine the damaging effect of the rock mass in the crushed zone and fractured area [15]. In addition, different fracture sizes and orientations affect the strength of the rock mass [16]. Thus, using the classical strength theory to roughly assess the damaging effect of the rock mass and then optimize the charge structure may result in some deviation.…”

Section: Introductionmentioning

confidence: 99%

Optimization Study of Water Interval Charge Structure Based on the Evaluation of Rock Damage Effect in Smooth Blasting

Wang,

Gong,

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

In tunnel smooth blasting, optimizing the water interval charging structure of peripheral holes is of great significance in improving the effect of smooth blasting and reducing the unit consumption of explosives. Addressing the issue of a single traditional evaluation standard, this paper proposes a composite index evaluation method for rock blasting damage in different zones, and the best charging structure is optimized according to the evaluation results. Taking Liyue Road Tunnel Light Smooth Blasting Project in Chongqing as the Research Background, the numeric models were established with ten kinds of charge structures, the charge structures and explosive quantity were optimized according to the evaluation results, and then the field tests were conducted. The results show that when the length of the water medium at the bottom of the hole is 20 cm, the damage range of the retained rock mass can be controlled while ensuring rock fragmentation. If the length of the water medium at the orifice and in the center of the hole is more than 30 cm, it will affect the superposition effect of the blast stress wave, resulting in under-excavation; in the preferred charge structure, the ratio of the length of the upper and lower explosives reaches 1:3, and the ratio of the length of the water medium is 2:2:1, which achieves a better rock-breaking effect in the field test.

show abstract

Intermediate Principal Stress Effects on the 3D Cracking Behavior of Flawed Rocks Under True Triaxial Compression

Sun,

Fei,

Wong

et al. 2024

Rock Mech Rock Eng

View full text Add to dashboard Cite

Crack initiation, growth, and coalescence in flawed rocks have been extensively studied for 2D (planar, penetrating) flaws under uniaxial/biaxial compression. However, little is known as to the mechanisms and processes of cracking from 3D flaws under true triaxial compression, where the intermediate principal stress ($$\sigma _2$$ σ 2 ) is distinguished from the major and minor principal stresses. In this work, we systematically investigate the effects of $$\sigma _2$$ σ 2 on the 3D cracking behavior of rock specimens with preexisting flaws, through the use of mechanistic simulations of mixed-mode fracture in rocks. We explore how two characteristics of $$\sigma _2$$ σ 2 , namely, (i) its orientation with respect to the flaw and (ii) its magnitude, affect two aspects of the cracking behavior, namely, (i) the cracking pattern and (ii) the peak stress. Results show that the orientation of $$\sigma _2$$ σ 2 exerts more control over the cracking pattern than the flaw inclination angle. The peak stress becomes highest when $$\sigma _1$$ σ 1 is parallel to the flaw, whereas it becomes lowest when $$\sigma _2$$ σ 2 is parallel to the flaw. Also, the effects of $$\sigma _2$$ σ 2 magnitude are more significant when $$\sigma _2$$ σ 2 becomes more oblique to the flaw plane. On the basis of our observations, we propose mechanisms underlying the cracking behavior of 3D flawed rocks under true triaxial compression. Highlights The effects of the intermediate principal stress ($$\sigma _2$$ σ 2 ) on the 3D cracking behavior of flawed rocks under true triaxial compression are systematically investigated. The orientation of $$\sigma _2$$ σ 2 exerts more control over the cracking pattern than the flaw inclination angle. The effects of $$\sigma _2$$ σ 2 magnitude become more significant when $$\sigma _2$$ σ 2 are more oblique to the flaw plane. Mechanisms underlying the cracking behavior of 3D flawed rocks under true triaxial compression are proposed based on the observations made.

show abstract

Size effects on the strength and cracking behavior of flawed rocks under uniaxial compression: from laboratory scale to field scale

Cited by 14 publications

References 57 publications

Analysis of Micro-Evolution Mechanism of 3D Crack Initiation in Brittle Materials with Hole under Uniaxial Compression

Analysis of Micro-Evolution Mechanism of 3D Crack Initiation in Brittle Materials with Hole under Uniaxial Compression

Optimization Study of Water Interval Charge Structure Based on the Evaluation of Rock Damage Effect in Smooth Blasting

Intermediate Principal Stress Effects on the 3D Cracking Behavior of Flawed Rocks Under True Triaxial Compression

Contact Info

Product

Resources

About