The Responses of Jointed Rock Mass under Dynamic Loads

2011 ◽  
Vol 230-232 ◽  
pp. 251-255 ◽  
Author(s):  
Zhe Ming Zhu
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Stress Waves ◽  
Dynamic Loads ◽  
Experimental Investigations ◽  
Rock Fracturing ◽  
Artificial Joints ◽  
Simulation Results

Joints can reflect and transmit stress waves, thus joints affect rock fracturing, and accordingly they could affect blasting efficiency. In this paper, numerical and experimental investigations have been implemented and the effect of joints on wave propagation and rock fracturing has been discussed. A dynamic numerical model of jointed rock mass has been established by using finite difference method. The simulation results show that as joints are parallel to wave propagation, the corresponding rock damage zones increase. Blasting experiments by using artificial joints have been carried out. Generally the experimental results agree with our numerical results.

scholarly journals A Numerical Simulation of Blasting Stress Wave Propagation in a Jointed Rock Mass under Initial Stresses

2021 ◽  
Vol 11 (17) ◽  
pp. 7873
Author(s):  
Qian Dong ◽  
Xinping Li ◽  
Yongsheng Jia ◽  
Jinshan Sun
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Initial Stress ◽  
Stress Wave ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Stress Waves ◽  
Initial Stresses ◽  
Stress Wave Propagation ◽  
Rock Masses

The initial stresses have a strong effect on the mechanical behavior of underground rock masses, and the initial stressed rock masses are usually under strong dynamic disturbances such as blasting and earthquakes. The influence mechanism of a blasting excavation on underground rock masses can be revealed by studying the propagation of stress waves in them. In this paper, the improved Mohr-Coulomb elasto-plastic constitutive model of the intact rock considering the initial damage was first established and numerically implemented in Universal Distinct Element Code (UDEC) based on the variation of the experimental stress wave velocity in the initial stressed intact rock, and the feasibility of combining the established rock constitutive model and the BB (Bandis-Barton) model which characterizes the nonlinear deformation of the joints to simulate stress waves across jointed rock masses under initial stress was validated by comparing the numerical and model test results subsequently. Finally, further parameter studies were carried out through the UDEC to investigate the effect of the initial stress, angle, and number of joints on the transmission of the blasting stress wave in the jointed rock mass. The results showed that the initial stress significantly changed the propagation of the stress waves in the jointed rock mass. When the initial stress was small, the transmission coefficients of the stress waves in the jointed rock were vulnerable to be influenced by the variation of the angle and the number of joints, while the effect of the angle and the number of joints on the stress wave propagation gradually weakened as the initial stress increased.

scholarly journals Constitutive Model of Stress-Dependent Seepage in Columnar Jointed Rock Mass

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 160 ◽  
Author(s):  
Zihao Niu ◽  
Zhende Zhu ◽  
Xiangcheng Que
Keyword(s):  
Rock Mass ◽  
Constitutive Model ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Hexagonal Prism ◽  
Columnar Jointed Rock Mass ◽  
Pentagonal Prism ◽  
Permeability Anisotropy ◽  
Simulation Results ◽  
Prism Model

Columnar jointed rock mass (CJRM) is a highly symmetrical natural fractured structure. As the rock mass of the dam foundation of the Baihetan Hydropower Station, the study of its permeability anisotropy is of great significance to engineering safety. Based on the theory of composite mechanics and Goodman’s joint superposition principle, the constitutive model of joints of CJRM is derived according to the Quadrangular prism, the Pentagonal prism and the Hexagonal prism model; combined with Singh’s research results on intermittent joint stress concentration, considering column deflection angles, the joint constitutive model of CJRM in three-dimensional space is established. For the CJRM in the Baihetan dam site area, the Quadrangular prism, the Pentagonal prism and the Hexagonal prism constitutive models were used to calculate the permeability coefficients of CJRM under different deflection angles. The permeability anisotropy characteristics of the three models were compared and verified by numerical simulation results. The results show that the calculation results of the Pentagonal prism model are in good agreement with the numerical simulation results. The variation of permeability coefficient under different confining pressures is compared, and the relationship between permeability coefficient and confining pressure is obtained, which accords with the negative exponential function and conforms to the general rule of joint seepage.

Experimental studies in wave propagation across a jointed rock mass

2011 ◽  
Vol 71 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Cengiz Kurtuluş ◽  
Maral Üçkardeş ◽  
Umut Sarı ◽  
Ş. Onur Güner
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Experimental Studies ◽  
Jointed Rock ◽  
Jointed Rock Mass
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