Application of Discrete-Element Numerical Simulation for Calculating the Stability of Dangerous Rock Mass: A Case Study

2020 ◽  
Vol 20 (12) ◽  
pp. 04020231
Author(s):  
Chong Shi ◽  
Bo Yang ◽  
Yiping Zhang ◽  
Junxiong Yang
2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.


2012 ◽  
Vol 594-597 ◽  
pp. 358-361
Author(s):  
Shan Shan Zhang ◽  
Yu Liang Wu

Collapse is one of the major geological disasters all over the world and threats to life and property safety of people. To make a better understanding of the reason it occurs and how to deal with it, the Kim-Yun-Mine collapse is researched. There are one dangerous rock mass and two collapse accumulation body. The basic characteristics of the collapse is described clearly according to the geological exploration data, and the stability of the dangerous rock mass and the collapse accumulated body is analyzed in the way of engineering geology and stereographic projection. At last, we put forward comprehensive control measures based on the results of stability analysis and collapse characteristics.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jun-hua Xue ◽  
Ke-liang Zhan ◽  
Xuan-hong Du ◽  
Qian Ma

In view of the damage of dynamic stress to the rock surrounding a mine roadway during coal mining, based on the actual geological conditions of Zhuji mine in Huainan, China, a UDEC model was established to study the influences of the thickness and strength of the direct roof above the coal seam and the anchorage effect on the stability of the roadway. The failure mechanism and effect of the dynamic stress on the rock surrounding a mine roadway were revealed. Under dynamic stress, cracks appear near the side of the roadway where the stress is concentrated. These cracks rapidly expand to the two sides of coal and rock mass. At the same time, the coal and rock mass at the top of the roadway fall, and finally, the two sides of coal and rock mass were broken and ejected into the roadway, causing a rock burst. However, when the same dynamic stress is applied to the roadway after supports are installed, there is no large-deformation failure in the roadway, which shows that, under certain conditions, rock bolting can improve the stability and seismic resistance of the surrounding coal and rock mass. Furthermore, by simulating the failure of surrounding rock with different strengths and thicknesses in the immediate roof, it is found that the thinner the roof, the greater the influence of the dynamic stress on the roadway; the stronger the roof is, the more likely the rock burst will occur with greater intensity under the same dynamic stress. A numerical simulation method was used to analyze the factors influencing rock bursting. The results provide a theoretical basis for research into the causes and prevention of rock bursts in deep mining areas.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Qingbo Li ◽  
Hongfei Wang ◽  
Mowen Xie ◽  
Weinan Liu

In this study, through an analysis of vibration response characteristics of joint surface stiffness on dangerous rock mass, the relationship formula between amplitude ratio of the dangerous rock mass to the bedrock and the length of the bonding section of the joint surface is determined. The stability of the rock mass can be evaluated by combining the formula with the existing rock-mass limit equilibrium theory. This study proposes the existence of a resonance bonding length for the dangerous rock mass. When the length of the bonding section reaches the resonance bonding length, the dangerous rock mass has the largest response to the bedrock vibration. The study found that when the length of the bonding section of the dangerous rock mass is longer than the resonance bonding length, the amplitude ratio increases with the decrease of the bonding section and increases with the increase of the vibration frequency of the bedrock. When the length of the bonding section of the dangerous rock body is shorter than the resonance bonding length, the amplitude ratio decreases with the decrease of the bonding section and decreases with the increase of the vibration frequency of the bedrock. Indoor experiments were conducted by collecting the vibration time-history curves of rock blocks and stone piers and performing analysis and calculation, which proved the accuracy of the analytical results. Through the amplitude ratio of the dangerous rock mass and the bedrock, the bonding length can be calculated. This method can improve the calculation accuracy of the stability coefficient K of the dangerous rock mass.


2008 ◽  
Vol 33-37 ◽  
pp. 657-662
Author(s):  
Xiao Jing Li ◽  
Wei Min Yang ◽  
Wei Shen Zhu ◽  
Shu Cai Li ◽  
Ai Hua Sun

The jointed rock mass distributed in the nature widely and its mechanical characteristic influenced the stability of the rock engineering badly. The cracks propagated and coalesced each other and macroscopic failure happened. Bolts were a kind of effective reinforcement instrument and they could prevent the cracks from propagating. However, the anchoring mechanism of bolts was not realized clearly and their reinforcement could not be reflected effectively in the numerical simulation yet. Based on the damage mechanics, a constitutive relation and damage equation of anchored jointed rock mass were presented in this paper. With a project application, the model was proved to be feasible one.


2020 ◽  
Vol 12 (3) ◽  
pp. 428-435
Author(s):  
Dashzhan NARODKHAN ◽  
◽  
Tuiak ISABEK ◽  
Rustam KHODJAEV ◽  
Nurbol KHUANGAN ◽  
...  

The open method of solid minerals winning occupies a significant place in the total opening of the mining complex deposits of the Republic of Kazakhstan. In the energy band, a prominent role belongs to the Ekibastuz coal basin, where a number of large coal strip mine operates. The level of subsurface, equal parts of spoil bank of the external and internal stripping after a while lead to complex problems of ensuring the stability and safety of mining operations. The location of large external rock dumps on the bead surface has a negative effect on the stability of the latter. The purpose of the work was to establish the degree of the external rock dump influence located on the bead surface on the stability of adjacent rock mass of the coalmine depending on the distance of the dump to the upper edge of the side. There was numerical simulation of stress-strain state of adjacent rock mass under action of distributed load from rock dump carried out. It has been shown that studies of any point stability of the array from this type of load should be carried out on the basis of elasticity and the use of the finite element method theory implemented in packages of programs oriented specifically to scientific and engineering applications. There are the methodology and results of numerical modeling of quantitative assessments of various sections stability of the side loaded with an external rock dump with a height of 160m presented on the example of «Ekibastuz» coal mine. Based on a certain theory of rock strength and the criteria for their discontinuity, limit estimates of the critical distance of the external rock dump from the upper edge of the side were obtained, at which the latter may lose stability.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wen-Lian Liu ◽  
Jia-Xing Dong ◽  
Su-Gang Sui ◽  
Han-Hua Xu ◽  
Run-Xue Yang ◽  
...  

Dangerous rock mass in the overhanging slope of Puerdu town has good free-face condition, high position, and great potential energy, identification and stability evaluation of which is a difficult problem in the disaster prevention. In this paper, the limit equilibrium method was used to evaluate the dangerous rock mass stability in the overhanging slope. Firstly, geomorphic characteristics and the distribution of dangerous rock mass are determined by the field geological survey. Secondly, six dangerous rock masses which may cause more threat are studied, with defining their failure modes and characteristic parameters. Finally, a simplified geological model is established, the stability coefficient of dangerous rock mass under different conditions is calculated by the limit equilibrium method, at the same time, stability analysis of dangerous rock mass is carried out based on the stereographic projection, and the hazard probability is estimated by the empirical formula. Results show that joints obviously developed in the dangerous rock mass of W1, W2, W3, W4, W5, and W6, with falling-type and toppling-type failure modes. In the natural condition, the dangerous rock mass is understable and unstable under the rainstorm and earthquake conditions. Consequently, rainstorm and earthquake are the key triggering factors of the instability and collapse of dangerous rock mass.


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