scholarly journals Vibration Safety Criteria for Surficial Rock Mass of Open Pit Slope Affected by Underground Mining Blasting Operations

2017 ◽  
Vol 11 (1) ◽  
pp. 627-637 ◽  
Author(s):  
Nan Jiang ◽  
Chang Xiong ◽  
Chuanbo Zhou ◽  
Xuedong Luo ◽  
Shiwei Lu ◽  
...  
Keyword(s):  
Rock Mass ◽  
Underground Mining ◽  
Ultimate Tensile Stress ◽  
Stress Waves ◽  
Open Pit ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Stress Criterion ◽  
The North ◽  
South Slope

Introduction: Blasting vibration velocity is an important index to evaluate the stability of mine slopes under blasting operations. Objective: In order to determine the blasting vibration safety criteria for slope rock mass scientifically and reasonably, the influence of stress waves on surficial rock mass of mine slopes was analyzed when stress waves propagate to the slope surface, and mathematical models for blasting vibration safety criteria are proposed based on the ultimate tensile stress criterion, the ultimate shear stress criterion and the Mohr-Coulomb criterion. Results and Conclusion: Combined with the field blasting operations during the open-pit to underground mining in Daye iron mine, the blasting vibration safety criteria is calculated. It is obtained that the blasting vibration safety criteria for the north slope and the south slope are 11.08cm/s and 10.20cm/s respectively. The results agree well with the Safety Regulations for Blasting in China and provide a reference to determine blasting vibration safety criteria for other similar projects.

Prediction of the Ground Vibration Rate during Large-scale Explosions in the Underground Conditions

2021 ◽  
pp. 41-45
Author(s):  
V.N. Tyupin ◽  
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Underground Mining ◽  
Calculated Data ◽  
Ground Vibration ◽  
Open Pit ◽  
Vibration Velocity ◽  
Earth Surface ◽  
Seismic Safety ◽  
The Earth

At present, to ensure seismic safety in massive explosions, the analytical dependence of the determination of the vibration velocity of M.A. Sadovsky rock mass is mainly used. This dependence is widely used in the creation of seismic-safe technologies for mineral deposits open-pit and underground mining. However, scientific research and production experience showed that the rate of oscillation depends on the energy parameters of the explosive, the diameter and length of its charges, the number of simultaneously exploded charges, the number of deceleration stages, the deceleration interval, etc. The purpose of this article is to predict the speed fluctuations of the massif on the earth surface when conducting the underground explosions depending on the parameters of large-scale explosions and physical-technical properties of the rock masses in the areas of explosion of the protected object. The formulas for calculating the velocity of rock mass on the earth surface during large-scale explosions in the underground conditions are substantiated and presented. The formulas were used for calculating the vibration velocities of the rock mass on the earth surface in accordance with the parameters of drilling and blasting operations during large-scale explosions in the mines of GK VostGOK. Comparison of theoretical (calculated) data and the results of actual measurements indicates their convergence. By changing the controlled parameters in the calculation formulas, it is possible to quantitatively reduce the seismic effect of a large-scale explosions on the protected objects. Further research will be aimed at studying the influence of tectonic faults, artificial contour crevices, filling massif or mined-out space on the rate of seismic-explosive vibrations during blasting operations in the mines. The research results can be used in the preparation of rules for conducting large-scale explosions at the underground mining.

Rock Mass Deformation Characteristics in High-Steep Slopes Influenced by Open-Pit to Underground Mining

2016 ◽  
Vol 34 (3) ◽  
pp. 847-866 ◽  
Author(s):  
Chuanbo Zhou ◽  
Shiwei Lu ◽  
Nan Jiang ◽  
Dingbang Zhang ◽  
Zhihua Zhang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Underground Mining ◽  
Open Pit ◽  
Deformation Characteristics ◽  
Rock Mass Deformation ◽  
Steep Slopes ◽  
Mass Deformation

scholarly journals Two-Dimensional Modeling of the Influence of Underground Mining Direction on Slope Stability in Coordinated Open-Pit and Underground Mining

2021 ◽  
Author(s):  
Bowen Liu ◽  
Zhenwei Wang ◽  
Xinpin Ding ◽  
Zhitao Wang ◽  
Bin Li
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Underground Mining ◽  
Mining Area ◽  
Two Dimensions ◽  
Open Pit ◽  
Engineering Practice ◽  
Inverse Slope ◽  
Coal Wall ◽  
Mining Face

Abstract Under a background of coordinated open-pit and underground mining engineering practice in the Pingshuo mining area, a combination of numerical simulations and similar-model experiments was used to study the influence of the underground mining direction on slope deformation in two dimensions. The results show that the disturbance caused by inverse-slope mining is more obvious than that caused by along-slope mining. Underground mining presents an asymmetric influence on the open-pit slope; the slope rock mass on the open-off cut side is disturbed more than that on the coal-wall side. Compared with the slope in front of the advancing direction of the underground mining face, the degree of rock-mass damage and stress concentration of the slope of the open-off cut side are more serious. As such, in coordinated open-pit and underground mining practice, an along-slope mining direction is recommended to reduce adverse effects on slope stability and improve the recovery rate of coal resources.

scholarly journals Determination of the Ultimate Underground Mining Depth considering the Effect of Granular Rock and the Range of Surface Caving

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Rongxing He ◽  
Jing Zhang ◽  
Yang Liu ◽  
Delin Song ◽  
Fengyu Ren
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Mechanical Model ◽  
Surface Deformation ◽  
Underground Mining ◽  
Mining Area ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Depth

Continuous mining of metal deposits leads the overlying strata to move, deform, and collapse, which is particularly obvious when open-pit mining and underground mining are adjacent. Once the mining depth of the adjacent open-pit lags severely behind the underground, the ultimate underground mining depth needs to be studied before the surface deformation extends to the open-pit mining area. The numerical simulation and the mechanical model are applied to research the ultimate underground mining depth of the southeast mining area in the Gongchangling Iron mine. In the numerical simulation, the effect of granular rock is considered and the granular rock in the collapse pit is simplified as the degraded rock mass. The ultimate underground mining depth can be obtained by the values of the indicators of surface movement and deformation. In the mechanical model, the modified mechanical model for the progressive hanging wall caving is established based on Hoke’s conclusion, which considers the lateral pressure of the granular rock. Using the limiting equilibrium analysis, the relationship of the ultimate underground mining depth and the range of surface caving can be derived. The results show that the ultimate underground mining depth obtained by the numerical simulation is greater than the theoretical calculation of the modified mechanical model. The reason for this difference may be related to the assumption of the granular rock in the numerical simulation, which increases the resistance of granular rock to the deformation of rock mass. Therefore, the ultimate underground mining depth obtained by the theoretical calculation is suggested. Meanwhile, the surface displacement monitoring is implemented to verify the reasonability of the ultimate underground mining depth. Monitoring results show that the indicators of surface deformation are below the critical value of dangerous movement when the underground is mined to the ultimate mining depth. The practice proves that the determination of the ultimate underground mining depth in this work can ensure the safety of the open-pit and underground synergetic mining.

Dynamical Response of Circular Tunnel with Steel Lining under the Action of Blasting Vibration

2010 ◽  
Vol 163-167 ◽  
pp. 4037-4042 ◽  
Author(s):  
Chang Ping Yi ◽  
Wen Bo Lu ◽  
Ling Feng ◽  
Gang Wang
Keyword(s):  
Rock Mass ◽  
Velocity Distribution ◽  
Expansion Method ◽  
Surrounding Rock ◽  
Vibration Velocity ◽  
Dynamical Response ◽  
Blasting Vibration ◽  
Circular Tunnel ◽  
Steel Lining ◽  
Wave Function Expansion Method

The wave function expansion method is used to analyze the interaction process of the blasting seismic wave and the adjacent circular tunnel with steel lining, the stress expression, displacement expression and vibration velocity expression of circular tunnel under the action of blasting vibration are deduced, the stress, displacement and vibration velocity distribution of surrounding rock mass and steel lining are presented under the definite condition. In terms of the stress and vibration velocity distribution and the tensile strength of the rock mass, the critical failure vibration velocity of surrounding rock mass is obtained.

scholarly journals Prediction of Blasting Vibration Velocity of Layered Rock Mass under Multihole Cut Blasting

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jie Zhu ◽  
Haixia Wei ◽  
Xiaolin Yang ◽  
Huaibao Chu
Keyword(s):  
Differential Equation ◽  
Rock Mass ◽  
Prediction Accuracy ◽  
Time History ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Underground Engineering ◽  
Layered Rock ◽  
Propagation Law ◽  
Layered Rock Mass

In the blasting construction of underground engineering in layered rock mass, the mechanism of cut blasting and the propagation law of blasting vibration waves are very complex. In this paper, a new method for predicting the blasting vibration velocity of layered rock mass under multihole cut blasting is proposed. The key steps include determining the equivalent elastic boundary and load, establishing the multidegree freedom model of blasting vibration and its motion differential equation, and solving the motion differential equation by time-history analysis method. Two multihole cut blasting tests of different schemes were carried out in the construction site of layered rock mass, and the measured results of blasting vibration waves were obtained. By comparing the time-history curves of the predicted and measured blasting vibration velocity, it can be seen that the time-history curves predicted by the proposed method can reflect the characteristics and attenuation law of blasting vibration waves, and the predicted waveforms are similar to the measured waveforms. By using the proposed method, the prediction accuracy for the peak velocity of blasting vibration in the two tests is 93% and 94%, respectively, and the prediction accuracy for the dominant frequency of blasting vibration in the two tests is 86% and 94%, respectively. The prediction accuracy of the main characteristic parameters of blasting vibration waves is high. So it can be proved that the prediction method proposed in this paper is feasible in effectiveness and accuracy, which can provide important theoretical guidance for the optimization of blasting design and the control of blasting vibration in underground engineering in layered rock mass.

scholarly journals Peningkatan Kestabilan Pilar Tambang Bawah Tanah Marmer di PT Gunung Marmer Raya

2020 ◽  
Vol 3 (1) ◽  
pp. 27-38
Author(s):  
Purwanto Purwanto
Keyword(s):  
Rock Mass ◽  
Safety Factor ◽  
Underground Mining ◽  
Underground Mine ◽  
Joint Movement ◽  
Pillar Stability ◽  
The North ◽  
Joint Monitoring ◽  
The Stability ◽  
Q System

PT Gunung Marmer Raya  (PT GMR), a room and pillar underground marble mining is located about  73 km to the north from Makassar, in Desa Tabo-Tabo, Kecamatan Bungoro, Kabupaten Pangkep. In the mining location, discontinuities are found as joint structure across the production area. The purpose of this service is to make pillar redesign that can improve the stability of underground mine. These activities start with field observation, determining the rock characteristic through sample testing in the laboratory, classifying the rock mass using Q-system method, up to redesigning a form of implementation to increase the stability of the marble underground mine. According to calculation of rock mass classification using Q-System, the recommended buffering is systematic bolting and fiber reinforced sprayed concrete as thick as 5-6 cm with spacing between bolts of 2.2 meters, or systematic bolting without concrete layering with spacing between-bolt 1.8 meter. Joint monitoring, especially on pillars, need to be done routinely so joint movement could be anticipated for progressive movement. The existing dimensions of pillar 5 m x 5 m in length and width is not recommended due to the safety factor is under 1,0  (unstable condition). Based on observation and analytic calculation, for each pillar height of up to 11 meters the pillar is recommended to redesign with length and width 5 m x 9 m for the chain pillar (safety factor around 1.35-1.49); and 5 m x 12 m for barrier pillars (safety factor around 1.58-1.74). Key Words: Underground mining; room and pillar method; Q-system classification system; pillar stability; marble mining.

Monitoring and Analysis of Blasting Vibration of Diversion Tunnel Excavation in Layered Rock Mass

2012 ◽  
Vol 249-250 ◽  
pp. 1047-1052 ◽  
Author(s):  
Hua Feng Deng ◽  
Min Zhu ◽  
Le Hua Wang ◽  
Ji Fang Zhou
Keyword(s):  
Rock Mass ◽  
Vibration Monitoring ◽  
Damage Effect ◽  
Good Effect ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Diversion Tunnel ◽  
Tunnel Excavation ◽  
Layered Rock ◽  
Layered Rock Mass

In order to insure the safety and stability of the existed dam body and dam curtain during the diversion tunnel excavation, the vibration velocities were analyzed based on in-site blasting vibration monitoring. Result shows that the elevation difference between explosion point and monitoring points has a great impact on the vibration velocity in addition to single fire dynamite and blast center distance. During data analysis, the traditional empirical formula of attenuation of blasting earthquake must be amended. Through contrasting and analyzing, the amended formula of attenuation of blasting earthquake wave is precise relatively. At the same time, two collapses during the diversion tunnel excavation were analyzed based on the characteristics of layered rock mass and fault distribution, and the explosion parameters were optimized, so that the damage effect of blasting vibration was controlled effectively. This research also takes a good effect in other similar works.

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