scholarly journals Linkage Analysis between Solid-Fluid Coupling and the Strength Reduction Method for Karst Cave Water Inrush in Mines

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yanlin Zhao ◽  
Jian Liao ◽  
Qiang Liu ◽  
Yang Li ◽  
Jianchao Cheng
Keyword(s):  
Pipe Flow ◽  
Reduction Method ◽  
Water Inrush ◽  
Strength Reduction ◽  
Karst Water ◽  
Karst Cave ◽  
Strength Reduction Method ◽  
Rock Pillar ◽  
Water Proof ◽  
Safety Thickness

The present paper aims to study the mechanical mechanism and characteristics of water irruption from Karst cave. Combining the nonlinear seepage-pipe coupling model with the strength reduction method, the linkage analysis of fluid solid coupling and strength reduction method are constructed to study the whole process of confined Karst cave water inrush. Taking the water inrush accident of Shibaijing of the Qiyi mine in south China as an example, the instability mechanism of the water-proof rock pillar and evolution of water inrush are discussed. It is suggested that water discharge on the working face augments with the increase in the reduction factor of the water-proof rock pillar before the rock pillar loses its stability. Once the rock pillar becomes unstable, Karst water bursts from confined Karst cave in a pipe flow shape, and the water irruption quantity reaches the peak value in a short time by adopting the pipe flow to simulate and then decreases slowly. The hydraulic rough flow at the initial stage changes into pipe laminar flow finally in the process of Karst water inrush, due to the constraint of Karst cave water reserve. The conception for the safety factor of the water-proof rock pillar introduced, the relation of the safety factor, Karst cave water pressure, and thickness of the water-proof rock pillar are studied. It is proposed that thickness of the water-proof rock pillar whose safety factor equals 1.5 is regarded as the calculating safety thickness of the water-proof rock pillar, and the safety thickness of the water-proof rock pillar setting in mining engineering should be equal to the sum of the blasthole depth, blasting disturbance depth, and the calculating safety thickness. The reason leading to Karst water inrush of Qiyi Mine is that without advanced boreholes, the water-proof rock pillar is set so small that it could not possess safety margin, so the confined Karst cave water breaks the water-proof rock pillar and bursts out. Combining the solid fluid coupling theory, pipe flow theory, and strength reduction method, the nonlinear mechanical response of confined Karst cave water inrush is studied, which provides a new study method for the whole process of confined Karst cave water inrush.

Numerical Simulation of Safe Distance between Concealed Karst Cave and Tunnel Based on Shear Strength Reduction Method Safety Factor Catastrophe

2014 ◽  
Vol 501-504 ◽  
pp. 1753-1756
Author(s):  
Yong Biao Lai ◽  
Mang Shu Wang ◽  
Xin Hua You
Keyword(s):  
Numerical Simulation ◽  
Safety Factor ◽  
Reduction Method ◽  
Strength Reduction ◽  
Karst Cave ◽  
Strength Reduction Method ◽  
Safe Distance ◽  
Shear Strength Reduction Method ◽  
Concealed Karst Cave ◽  
Shear Strength Reduction

The numerical simulation method of safe distance between concealed karst cave and tunnel based on shear strength reduction method safety factor catastrophe is proposed. The safety factor of different distance between concealed karst cave and tunnel can be obtained using strength reduction finite element method numerical calculation with the finite element solution non convergence as the standard rock damage, then compare the safety factor of different distance, the catastrophe of safety factor corresponding to the distance is the safe distance between concealed karst cave and tunnel, and the plastic zone of rock stratum between concealed karst cave and tunnel is reaching run-through state, which is verified by engineering example.

Analysis of Unstable Rock-Mass Stability Based on Limit Equilibrium Method and Strength Reduction Method

2016 ◽  
Vol 858 ◽  
pp. 73-80
Author(s):  
Ying Kong ◽  
Hua Peng Shi ◽  
Hong Ming Yu
Keyword(s):  
Rock Mass ◽  
Failure Mode ◽  
Posterior Margin ◽  
Reduction Method ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Strength Reduction ◽  
Strength Reduction Method ◽  
Rock Masses ◽  
Unstable Rock

With the slope unstable rock masses of a stope in Longsi mine, Jiaozuo City, China as the target, we computed and analyzed the stability of unstable rock masses using a limit equilibrium method (LEM) and a discrete element strength reduction method (SRM). Results show that the unstable rock masses are currently stable. Under the external actions of natural weathering, rainfall and earthquake, unstable rock mass 1 was manifested as a shear slip failure mode, and its stability was controlled jointly by bedding-plane and posterior-margin steep inclined joints. In comparison, unstable rock mass 2 was manifested as a tensile-crack toppling failure mode, and its stability was controlled by the perforation of posterior-margin joints. From the results of the 2 methods we find the safety factor determined from SRM is larger, but not significantly, than that from LEM, and SRM can simulate the progressive failure process of unstable rock masses. SRM also provides information about forces and deformation (e.g. stress-strain, and displacement) and more efficiently visualizes the parts at the slope that are susceptible to instability, suggesting SRM can be used as a supplementation of LEM.

scholarly journals Stability Analysis of Jointed Rock Slope by Strength Reduction Technique considering Ubiquitous Joint Model

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ruili Lu ◽  
Wei Wei ◽  
Kaiwei Shang ◽  
Xiangyang Jing
Keyword(s):  
Rock Slope ◽  
Reduction Method ◽  
Domain Size ◽  
Jointed Rock ◽  
Strength Reduction ◽  
Hydropower Station ◽  
Strength Reduction Method ◽  
Vertical Side ◽  
The Stability ◽  
Jointed Rock Slope

In order to study the failure mechanism and assess the stability of the inlet slope of the outlet structure of Lianghekou Hydropower station, the strength reduction method considering the ubiquitous joint model is proposed. Firstly, two-dimension numerical models are built to investigate the influence of the dilation angle of ubiquitous joints, mesh discretization, and solution domain size on the slope stability. It is found that the factor of safety is insensitive to the dilation angle of ubiquitous joints and the solution domain size but sensitive to the mesh discretization when the number of elements less than a certain threshold. Then, a complex three-dimension numerical model is built to assess the stability of the inlet slope of the outlet structure of Lianghekou Hydropower station. During the strength reduction procedure, the progressive failure process and the final failure surface of the slope are obtained. Furthermore, the comparison of factors of safety obtained from strength reduction method and analytical solutions indicates that the effect of vertical side boundaries plays an important role in the stability of jointed rock slope, and the cohesive force is the main contribution to the resistant force of vertical side boundaries.

Stability Analysis of Dam Slope by Double Safety Factors of Dynamic Local Strength Reduction Method

2015 ◽  
Vol 744-746 ◽  
pp. 593-596
Author(s):  
Yuan Meng
Keyword(s):  
Internal Friction ◽  
Reduction Method ◽  
Failure Process ◽  
Friction Angle ◽  
Strength Reduction ◽  
Internal Friction Angle ◽  
Material Strength ◽  
Strength Reduction Method ◽  
Strength Parameters ◽  
Local Strength

When calculating the dam slope failure process, traditional strength reduction method doesn't consider the difference of decay rate between cohesion and internal friction angle and discount the strength parameters for all elements. This paper uses two different reduction factors for material strength parameters, slope cohesion and internal friction angle. Based on the yield approach index criterion, we change the reduction region in time and put forward a double safety factor of dynamic local strength reduction method for engineering analysis of dam slope stability.

Analysis of Slope Instability Based on Strength Reduction Method

2012 ◽  
Vol 170-173 ◽  
pp. 1238-1242
Author(s):  
Xue Wei Li ◽  
Xin Yuan ◽  
Xiao Wei Li
Keyword(s):  
Plastic Zone ◽  
Reduction Method ◽  
Limit Equilibrium ◽  
Strength Reduction ◽  
Slope Instability ◽  
Strength Reduction Method ◽  
Numerical Convergence ◽  
Safety Coefficient ◽  
Reduction Coefficient ◽  
Slope Factor

Abstract. Combined the strength reduction method with ABAQUS, the development of the slope plastic strain of different reduction coefficient is obtained by constantly adjusting reduction coefficient to change the strength index of the soil. The reduction coefficient is obtained from the criterion of numerical convergence and displacement mutation and plastic zone breakthrough. Through the analysis and comparison with the results, the reduction coefficient by the criterion of displacement mutation is consistent with the result of the criterion of plastic zone breakthrough. The reduction coefficient is the safety coefficient of the slope, and compared and analyzed with the slope factor of limit equilibrium method Bishop. The result shows that the displacement mutation and the plastic zone breakthrough as criterions to judge the slope instability are reasonable.

Failure Mechanism of a Slope Anti-Sliding Pile

2013 ◽  
Vol 639-640 ◽  
pp. 593-597
Author(s):  
Lin Chen ◽  
Yong Yao ◽  
Jiong Yang ◽  
Zhao Qiang Zhang
Keyword(s):  
Finite Element ◽  
Failure Mechanism ◽  
Reduction Method ◽  
Strength Reduction ◽  
Strength Reduction Method ◽  
Analysis Method ◽  
Feasible Method ◽  
Finite Element Software ◽  
Slope Excavation ◽  
Pile Design

According to finite element strength reduction method，the article has discussed the failure mechanism of anti-sliding pile by using finite element software MIDAS /GTS ，exploration report and anti-sliding pile design data.The comparative analysis shows that the failure of anti-siding pile is contributed by the slope excavation and rainwater.The analysis method and results can provide reference significance to other anti-sliding pile design.This paper also provide a feasible method for prediction of consequence in slope excavation.

Sign in / Sign up

Export Citation Format

Share Document