scholarly journals The Effect of Joint Dip Angle on the Mechanical Behavior of Infilled Jointed Rock Masses under Uniaxial and Biaxial Compressions

Processes ◽  
2018 ◽  
Vol 6 (5) ◽  
pp. 49 ◽  
Author(s):  
Guansheng Han ◽  
Hongwen Jing ◽  
Yujing Jiang ◽  
Richeng Liu ◽  
Haijian Su ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Jointed Rock ◽  
Rock Masses ◽  
Jointed Rock Masses ◽  
Dip Angle

scholarly journals Numerical Modeling on Dynamic Characteristics of Jointed Rock Masses Subjected to Repetitive Impact Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jie Liu ◽  
Yan-Bin Song ◽  
Yue-Mao Zhao
Keyword(s):  
Rock Mass ◽  
Impact Loading ◽  
Jointed Rock ◽  
Stress Waves ◽  
Rock Masses ◽  
Jointed Rock Masses ◽  
Numerical Tests ◽  
Repetitive Impact ◽  
Dip Angle ◽  
Energy Dissipated

A discrete element method code was used to investigate the damage characteristics of jointed rock masses under repetitive impact loading. The Flat-Joint Contact Model (FJCM) in the two-dimensional particle flow code (PFC2D) was used to calibrate the microparameters that control the macroscopic behavior of the rock. The relationship between macro- and microparameters by a series of uniaxial direct tension and compression numerical tests based on an orthogonal experimental design method was obtained to calibrate the microparameters accurately. Then, the Synthetic Rock Mass (SRM) method that incorporates joints into the calibrated particle model was used to construct large-scale jointed rock mass specimens, and the repetitive drop hammer impact numerical tests on SRM specimens with different numbers of horizontal joints and dip angle joints were carried out to study the damage evolution, stress wave propagation, and energy dissipation characteristics. The results show that the greater the number of joints, the greater the number of cracks generated, the greater the degree of damage, and the more energy dissipated for rock masses with horizontal joints. The greater the dip angle of joints, the less the number of cracks generated, the less the degree of damage, and the less energy dissipated for rock masses with different dip angles of joints. The impact-induced stress waves will be reflected when they encounter preexisting joints in the process of propagation. When the reflected stress waves meet with subsequent stress waves, the stress waves will change from compressional waves to tensile waves, producing tensile damage inside rock masses.

scholarly journals Model Test Research on the End Bearing Behavior of the Large-Diameter Cast-in-Place Concrete Pile for Jointed Rock Mass

2016 ◽  
Vol 2016 ◽  
pp. 1-15
Author(s):  
Jingwei Cai ◽  
Aiping Tang ◽  
Xinsheng Yin ◽  
Xiaxin Tao ◽  
Shibo Tao
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Large Diameter ◽  
Jointed Rock ◽  
Single Pile ◽  
Rock Masses ◽  
Jointed Rock Masses ◽  
End Bearing Capacity ◽  
Concrete Pile ◽  
Dip Angle

For large-diameter, cast-in-place concrete piles, the end bearing capacity of a single pile is affected by discontinuous surfaces that exist in natural rock masses when the bearing layer of the pile end is located in the rock layer. In order to study the influence of the jointed dip angle on the bearing characteristics of the pile end, the discrete element models are adopted to simulate the mechanical characteristics of the jointed rock masses, and the model tests of the failure mode of the jointed rock masses were also designed. The results of the numerical calculations and modeling tests show that the joints, which have a filtering effect on the internal stress of the bedrock located at the pile end, change the load transferring paths. And the failure mode of the jointed rock foundation also changes as jointed dip angle changes. The rock located at the pile end generally presents a wedge failure mode. In addition, the Q-S curves obtained by model tests show that the ultimate end bearing capacity of a single pile is influenced by the jointed dip angle. The above results provide an important theoretical basis for how to correctly calculate end resistance for a cast-in-place concrete pile.

A numerical study on mechanical behavior of jointed rock masses after tunnel excavation

2020 ◽  
Vol 13 (11) ◽  
Author(s):  
Wanzhi Zhang ◽  
Bangshu Xu ◽  
Jie Mei ◽  
Guangyao Yue ◽  
Weihang Shi
Keyword(s):  
Mechanical Behavior ◽  
Numerical Study ◽  
Jointed Rock ◽  
Rock Masses ◽  
Tunnel Excavation ◽  
Jointed Rock Masses

Numerical Study of the Mechanical Behavior of Nonpersistent Jointed Rock Masses

2016 ◽  
Vol 16 (1) ◽  
pp. 04015035 ◽  
Author(s):  
M. Bahaaddini ◽  
P. Hagan ◽  
R. Mitra ◽  
B. K. Hebblewhite
Keyword(s):  
Mechanical Behavior ◽  
Numerical Study ◽  
Jointed Rock ◽  
Rock Masses ◽  
Jointed Rock Masses

An experimental study of mechanical behavior of brittle rock-like specimens with multi-non-persistent joints under uniaxial compression and damage analysis

2019 ◽  
Vol 28 (10) ◽  
pp. 1490-1522 ◽  
Author(s):  
Wendong Yang ◽  
Guizhi Li ◽  
PG Ranjith ◽  
Lindong Fang
Keyword(s):  
Mechanical Behavior ◽  
Young’S Modulus ◽  
Uniaxial Compression ◽  
Joint Angle ◽  
Young's Modulus ◽  
Jointed Rock ◽  
Peak Strength ◽  
Rock Masses ◽  
Jointed Rock Masses ◽  
Joint Length

The mechanical behavior of jointed rock masses significantly affects the stability of rock engineering applications. In this paper, the peak strength, Young's modulus and failure patterns of brittle rock-like specimens with multi-non-persistent joints under uniaxial compression are investigated. The joint geometry is defined by four factors: joint angle, spacing, joint length, and rock bridge length. The experiment results show that the joint angle has the greatest influence on the peak strength and Young's modulus of specimens, followed by joint length. A damage mechanical theory is adopted which deals with some sets of joints distributed in rock masses. Based on the geometrical distribution of joints, a macro damage model which considers the influence of the normal vector and area density of joints is used to describe the joints. The peak strength and Young's modulus of jointed specimens predicted by the damage mechanics method reflect the trend of the experimental results, which proves the influence of initial geometric damage of joints on the peak strength and Young's modulus of jointed specimens. The initial geometric damage of joints is mainly induced by the joint area density. Finally, from the micro damage aspect, to analyze the damage evolution and strain softening process of jointed rock masses, a modified numerical model (damage strainsofting model) on the basis of secondary development in fast Lagrangian analysis of Continua is proposed to simulate the fracture development of jointed rock masses. The peak strengths, Young's modulus and failure modes of rock specimens with non-persistent joints under uniaxial compressions are simulated and compared with the results obtained from the lab experiments indicating that the model is capable to replicate the physical processes.

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