scholarly journals Failure of Rock Slopes With Intermittent Joints: Failure Process and Stability Calculation Models

2021 ◽  
Author(s):  
Zihan Zhou ◽  
Yanjun Shen ◽  
Zhonghui Chen
Keyword(s):  
Inclination Angle ◽  
Failure Process ◽  
Open Pit ◽  
Rock Slopes ◽  
Type B ◽  
Stability Calculation ◽  
Open Pit Mines ◽  
Type C ◽  
The Stability ◽  
Joint Inclination

Abstract Rock slopes with intermittent joints in open-pit mines are complex geological bodies composed of intact rock and discontinuous structural planes, and their stability analysis are necessary for mine disaster prevention. In this study, a series of base friction tests were performed to determine the failure process and displacement field evolution of rock slopes with intermittent joints using the speckle technique of a noncontact measurement system. Next, stability calculation models of the slopes were established from the energy perspective using the plastic limit analysis theory, and the effects of the joint inclination angle and coalescence coefficient of rock bridges on the slope stability were evaluated. The four main conclusions are as follows. (1) The failure of rock slopes with intermittent joints shows the feature of collapse-lower traction-upper push. (2) Based on the failure modes of rock bridges in slopes, the failure of rock slopes with intermittent joints could be divided into three types: tensile coalescence (Type A), shear coalescence (Type B), and tensile–shear coalescence (Type C). (3) Among the three slope types, the stability of the Type A slope is significantly influenced by rock cohesion, whereas that the Type B slope is significantly influenced by joint cohesion. The stability of the Type C slope is significantly influenced by the joint inclination angle and joint friction angle. (4) The local-stable slope is unstable while the first through-tensile crack in the zone of the potential sliding body higher than the critical instability height appeared. This study guides the stability evaluation and instability prediction of jointed rock slopes in open-pit mines.

Research on 2D Limit Equilibrium Method of Slopes Considering the Effect of Horizontal In Situ Stress

2013 ◽  
Vol 671-674 ◽  
pp. 245-250
Author(s):  
Wen Hui Tan ◽  
Ya Liang Li ◽  
Cong Cong Li
Keyword(s):  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
In Situ Stress ◽  
Open Pit ◽  
Open Pit Mines ◽  
Equilibrium Method ◽  
Iron Mine ◽  
The Stability ◽  
Slice Method

At present, in-situ stress was not considered in Limit Equilibrium Method (LEM) of slopes, the influence of in-situ stress is very small on the stability of conventional slopes, but in deep-depressed open-pit mines, the influence should not be neglected. Formula for calculating the Factor of Safety (FOS) under the effect of horizontal in-situ stress was deduced using General Slice Method (GSM) of two-dimensional (2D) limit equilibrium method in this paper，a corresponding program SSLOPE was built, and the software was used in a deep- depressed open-pit iron mine. The results show that the FOS of the slope decreased by 20% when horizontal in-situ stress is considered, some reinforcements must be taken. Therefore, the influence of in-situ stress on slope stability should be taken into account in deep open –pit mines.

Forecasting landslide at slope-scale: past achievements, present challenges and future perspectives

2020 ◽  
Author(s):  
Emanuele Intrieri ◽  
Tommaso Carlà ◽  
Giovanni Gigli ◽  
Nicola Casagli
Keyword(s):  
Applied Mathematics ◽  
Warning System ◽  
Open Pit ◽  
Economic Losses ◽  
Open Pit Mines ◽  
Recent Advancement ◽  
Future Challenges ◽  
Set Up ◽  
The Stability ◽  
Kinematics Parameters

<p>In general, the most reliable parameters to forecast the occurrence of a landslide are kinematics parameters, such as displacement, velocity and acceleration, since they represent the direct indicator of the stability conditions of a slope. Despite recent advancement in satellite interferometry, the highest temporal resolution, necessary to set up an effective early warning system, are still achievable from ground-based instrumentation.</p><p>Within this framework a few methods to forecast the time of failure of landslides at slope-scale have been developed in the last decades and, in many instances, they have been successfully used to prevent casualties and economic losses.</p><p>Common applications include public safety situations and open-pit mines, for which accurate warnings are crucial to protect workers and at the same time avoid unnecessary interruptions of the extraction activities.</p><p>In this work, a review of the most relevant kinematics-based forecasting methods is presented. Some examples are shown to illustrate the respective advantages, limitations and range of applicability of each method. Future challenges, trends and opportunities provided by technological innovations and scientific advances, also in related fields such as Material Science and Applied Mathematics, are also presented.</p>

scholarly journals Study on the Influence of Rainfall Infiltration on the High rock Slope of Open-pit Mine Stability using a New Nonlinear Strength Reduction Method

2021 ◽  
Author(s):  
Tianbai Zhou ◽  
Lingfan Zhang ◽  
Jian Cheng ◽  
Jianming Wang ◽  
Xiaoyu Zhang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Rock Slope ◽  
Reduction Method ◽  
Strength Reduction ◽  
Open Pit Mine ◽  
Open Pit ◽  
Strength Reduction Method ◽  
Rock Slopes ◽  
High Rock Slope ◽  
The Stability

Abstract Due to long-term mining, a series of high and steep rock slopes have been formed in the open-pit mine. For high rock slopes, rainfall infiltration is the main cause of landslide. Therefore, the stability analysis of high rock slope under rainfall has become a key issue in the open-pit mine engineering. In this work, aiming at the high stress condition of high rock slope, the instantaneous internal friction angle and instantaneous cohesion of rock mass under different stress states are deduced, and the a nonlinear strength reduction method for high rock slope is established according to the relationship between normal stress and shear stress of rock mass under the Hoke-Brown criterion. The numerical calculation results show that the factor of safety (FOS) for high rock slope calculated by the proposed method is more reasonable. Taking the southwest slope of Dagushan Iron Mine as the research background, the safety factors of high rock slope under different rainfall conditions are calculated by COMSOL Multiphysics. And the stability analysis of high rock slope in open-pit mine under rainfall are carried out.

scholarly journals Investigating the Failure Mechanism of Jointed Rock Slopes Based on Discrete Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Chao Peng ◽  
Qifeng Guo ◽  
Zhenxiong Yan ◽  
Minglong Wang ◽  
Jiliang Pan
Keyword(s):  
Rock Mass ◽  
Failure Mechanism ◽  
Failure Process ◽  
Structural Complexity ◽  
Jointed Rock ◽  
Research Area ◽  
Open Pit ◽  
Particle Model ◽  
Rock Slopes ◽  
Synthetic Rock

This paper presents a comprehensive engineering method to investigate the failure mechanism of the jointed rock slopes. The field geology survey is first carried out to obtain the slope joint data. A joint network model considering the structural complexity of rock mass is generated in the PFC software. The synthetic rock mass (SRM) approach for simulating the mechanical behavior of jointed rock mass is employed, in which the flat-jointed bonded-particle model (FJM) and smooth joint contact model (SJM) represent intact rock and joints, respectively. Subsequently, the effect of microparameters on macromechanical properties of rock is investigated for parameter calibration. Moreover, the scale effect is analyzed by multiscale numerical tests, and the representative elementary volume (REV) size in the selected research area is found as 16 m × 16  m × 16 m. The microparameters of the SRM model are calibrated to match the mechanical properties of the engineering rock mass. Finally, an engineering case from Shuichang open-pit mine is analyzed and the failure process of the slope during the excavation process from micro- to macroscale is obtained. It has been found that failure occurs at the bottom of the slope and gradually develops upwards. The overall failure of the slope is dominated by the shallow local tension fracture and wedge failure.

Geotechnical assessments of the stability of slopes at the Cakmakkaya and Damar open pit mines (Turkey): a case study

2009 ◽  
Vol 61 (4) ◽  
pp. 741-755 ◽  
Author(s):  
Fehmi Arikan ◽  
Fatih Yoleri ◽  
Sureyya Sezer ◽  
Dincer Caglan ◽  
Bengu Biliyul
Keyword(s):  
Open Pit ◽  
Open Pit Mines ◽  
Stability Of Slopes ◽  
The Stability

scholarly journals Application of Double Strength Reduction Factor Method in the Stability Analysis of Rock Slopes

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jiawei Lu ◽  
Jixun Zhang ◽  
Xuhua Ren ◽  
Yunrui Deng
Keyword(s):  
Stability Analysis ◽  
Failure Process ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Rock Slopes ◽  
Reduction Principle ◽  
Strength Reduction Factor ◽  
Factor Method ◽  
Weak Interlayer ◽  
The Stability

The cohesion c and internal friction angle φ play different roles in the progressive failure process of the slope, which indicates that the reduction factors kc and kφ should be different in the calculation. Based on this, the program of double strength reduction factor method was compiled with FISH language, in order to study its application in the rock slopes under different distributions of weak interlayer, and the following conclusions were drawn: (1) the plastic zone calculated by double strength reduction factor method is generally distributed in the weak interlayer, which is basically consistent with the calculation result of the traditional method; (2) the degree to which c and φ play a role is related to the inclination angle of the bottom sliding surface of the unstable block θ. If θ < 45°, φ will play a greater role. If θ ≥ 45°, c will play a greater role; (3) according to the “Pan’s principle,” the matching reduction principle of “kc > kφ” can be adopted when θ < 45°, and the matching reduction principle of “kc < kφ” can be adopted when θ ≥ 45°; (4) the definition of the comprehensive safety factor “K2” in the text is more suitable for the application of double strength reduction factor method in the stability analysis of rock slopes. The applicability of the above conclusions is verified by an actual engineering.

scholarly journals Exploring the Relation between Seismic Coefficient and Rock Properties Through Field Measurements and Empirical Model for Evaluating the Effect of Blast-Induced Ground Vibration in Open- Pit Mines: A Case Study at the Thuong Tan III Quarry (Vietnam)

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Quang Hieu TRAN
Keyword(s):  
Empirical Model ◽  
Empirical Equation ◽  
Ground Vibration ◽  
Field Measurements ◽  
Open Pit ◽  
Rock Properties ◽  
Open Pit Mines ◽  
Surrounding Environment ◽  
The Stability

Blasting is one of the most effective methods for fragmenting rock in quarries. Nevertheless, itsadverse effects are significant, especially blast-induced ground vibration. Field measurement andempirical equations are simple methods to determine and estimate the intensity of blast-induced groundvibration. However, we cannot evaluate the effects of blast-induced ground vibration on the surroundingenvironment based on these outcomes. Therefore, this study explores the relation between seismiccoefficient and rock properties through field measurements and an empirical model for evaluating theeffect of blast-induced ground vibration in open-pit mines. Accordingly, the seismic coefficient (K) isconsidered the main objective in this study. Firstly, it was determined based on the rock properties.Subsequently, an empirical model for estimating blast-induced ground vibration was developed based onfield measurements. This empirical equation was then expanded to determine K to check whether itmatches the determined K by the rock properties. Finally, it was used as the threshold to determine themaximum explosive charged per delay to ensure the safety of the surrounding environment from blastinducedground vibration. For this aim, the Thuong Tan III quarry (in Binh Duong province, Vietnam)was selected as a case study. Fifth-teen blasting events with a total of 75 blast-induced ground vibrationvalues were recorded and collected. An empirical equation for estimating blast-induced ground vibrationwas then developed based on the collected dataset, and K was determined in the range of 539 to 713 forthe Thuong Tan III quarry. Based on the measured blast-induced ground vibrations, developed empiricalmodel, and K values, the Phase 2 software was applied to simulate the effects of blast-induced groundvibration on the stability of slopes as one of the impacts on the surrounding environment. From thesimulation results, we can determine the maximum explosive charged per delay for each type of rock toensure the stability of the slope.

Sign in / Sign up

Export Citation Format

Share Document