Research of Safe Distance between Concealed Karst Cave and Tunnel

2013 ◽  
Vol 405-408 ◽  
pp. 1283-1287
Author(s):  
Yong Biao Lai ◽  
Chun Sheng Qiao ◽  
Chen Guang Bai
Keyword(s):  
Catastrophe Theory ◽  
Total Potential Energy ◽  
Karst Cave ◽  
Safe Distance ◽  
Rock Stratum ◽  
Distance Calculation ◽  
Total Potential ◽  
Concealed Karst Cave ◽  
The Stability ◽  
Rock Strata

Based on the catastrophe theory, a research method of safe distance between concealed karst cave and tunnel is put forward. The stability of rock stratum between concealed karst cave and tunnel is evaluated by the catastrophe theory, the catastrophe mode of rock strata system destabilization is established through the research of rock stratum total potential energy between karst cave and tunnel, then the safe distance calculation formula between concealed karst cave and tunnel are deduced, which is veried by an engineering example.

Study of Safe Distance Criterion between Concealed Karst Cave and Tunnel

2014 ◽  
Vol 556-562 ◽  
pp. 849-852 ◽  
Author(s):  
Yong Biao Lai ◽  
Meng Shu Wang ◽  
Xin Hua You
Keyword(s):  
Surrounding Rock ◽  
Karst Cave ◽  
Instability Mechanism ◽  
Safe Distance ◽  
Rock Stratum ◽  
Safety Coefficient ◽  
Concealed Karst Cave ◽  
Comparison And Analysis ◽  
Simulation Results ◽  
The Stability

On the basis of analysis of the stability criterion of surrounding rock and instability mechanism of the rock stratum between concealed karst cave and tunnel, the rock stratum energy catastrophe and safety coefficient catastrophe as safe distance criterion between concealed karst cave and tunnel were put forward, then the comparison and analysis of numerical simulation results based on the run-through of plastic zone criterion, energy catastrophe criterion and safety coefficient catastrophe criterion were carried out with engineering examples, the results showed that energy catastrophe criterion was more reasonable.

Numerical Simulation Method of Safe Distance between Concealed Karst Cave and Tunnel Based on Energy Catastrophe

2013 ◽  
Vol 353-356 ◽  
pp. 1470-1474
Author(s):  
Yong Biao Lai ◽  
Meng Shu Wang ◽  
Cheng Guang Bai
Keyword(s):  
Numerical Simulation ◽  
Catastrophe Theory ◽  
Simulation Method ◽  
Karst Cave ◽  
Safe Distance ◽  
Rock Stratum ◽  
Catastrophe Model ◽  
Numerical Simulation Method ◽  
Concealed Karst Cave ◽  
Distance Change

Stability of rock stratum between concealed karst cave and tunnel is evaluated by the catastrophe theory. The numerical simulation method of safe distance between concealed karst cave and tunnel is proposed based on catastrophe theory energy catastrophe. Through array of rock stratum energy change and distance change between concealed karst cave and tunnel, a cusp catastrophe model of safe distance between concealed karst cave and tunnel is built. The simulation of safe distance between concealed karst cave and tunnel can be finished by Ansys program and Matlab, and automatically calculates the safe distance by a compile interface program, which is verified by engineering example.

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.

Dilute Aqueous Dispersions of Zro2 And Al2O3

1985 ◽  
Vol 60 ◽  
Author(s):  
Evelyn M. De Liso ◽  
W. Roger Cannon ◽  
A. Srinivasa Rao
Keyword(s):  
Potential Energy ◽  
Total Potential Energy ◽  
Alumina Powder ◽  
Maximum Height ◽  
Colloidal Interactions ◽  
Total Potential ◽  
Particle Size Data ◽  
Theoretical Predictions ◽  
Alumina Composite ◽  
The Stability

AbstractColloidal interactions in a heteroparticulate mixture of zirconia and alumina in water were studied for use in a transformation toughened alumina composite. The microelectrophoresis technique was used to measure the mobility of three zirconia powders and an alumina powder. The electro-phoretic mobility and particle size data were used to calculate total potential energy curves. The maximum height of the total potential energy barrier was used to predict the stability of a zirconia/alumina mixture. Theoretical predictions were compared to experimental results obtained from sedimentation and rheology measurements carried out as a function of pH of the dispersion. For a 5 v/o aqueous zirconia/alumina system stable dispersions were made at pH 3 and pH 5.

Predicting Model of Safe Distance between Tunnel and Karst Cave

2013 ◽  
Vol 470 ◽  
pp. 862-865
Author(s):  
Yong Biao Lai ◽  
Meng Shu Wang ◽  
Cheng Uang Bai
Keyword(s):  
Poisson Ratio ◽  
Pressure Coefficient ◽  
Influence Factors ◽  
Friction Angle ◽  
Support Vector ◽  
Karst Cave ◽  
Safe Distance ◽  
Predicting Model ◽  
Rock Density ◽  
Concealed Karst Cave

A method of predicting safe distance between tunnel and karst cave based on support vector machine was proposed, 10 parameters (rock density,elasticity modulusE, poisson ratio, friction angle, cohesionC, lateral pressure coefficient , the karst cave spanL,rate between height and span of the Karst caveR, tunnel deepH,cave position) were chosen for safe distance influence factors, then an intelligent predicting model of safe distance between tunnel and karst cave was built, this predicting model can predict 7 kinds position of safe distance between tunnel and concealed karst cave and was feasible and high prediction precision, which was verified by engineering example.

MODEL OF BINDING ALPHA-PARTICLES AND APPLICATIONS TO SUPERHEAVY ELEMENTS

2005 ◽  
Vol 14 (04) ◽  
pp. 635-643 ◽  
Author(s):  
K. A. GRIDNEV ◽  
S. YU. TORILOV ◽  
D. K. GRIDNEV ◽  
V. G. KARTAVENKO ◽  
W. GREINER
Keyword(s):  
Pair Potential ◽  
Total Potential Energy ◽  
Binding Energies ◽  
Alpha Particles ◽  
Superheavy Nuclei ◽  
Lennard Jones ◽  
Total Potential ◽  
Stability Island ◽  
The Stability ◽  
Good Agreement

A model of nuclear matter built from alpha-particles is proposed. In this model, nuclei possess the molecular-like structure. Analyzing the numbers of bonds, one gets the formula for the binding energy of a nucleus. The structure is determined by the minimum of the total potential energy, where interaction between alpha-particles is pairwise and the pair-potential is of Lennard–Jones type. The calculated binding energies show a good agreement with experiment. Calculations predict the stability island for superheavy nuclei around Z=120.

scholarly journals Computation of elastic equilibria of complete Möbius bands and their stability

2018 ◽  
Vol 24 (4) ◽  
pp. 939-967 ◽  
Author(s):  
Alexander Moore ◽  
Timothy Healey
Keyword(s):  
Local Minimum ◽  
Systematic Approach ◽  
Equilibrium Configuration ◽  
Total Potential Energy ◽  
Surface Model ◽  
Challenging Problem ◽  
Total Potential ◽  
The Stability ◽  
Kirchhoff Theory ◽  
Stability Results

Determining the equilibrium configuration of an elastic Möbius band is a challenging problem. In recent years numerical results have been obtained by other investigators, employing first the Kirchhoff theory of rods and later the developable, ruled-surface model of Sadowsky–Wunderlich. In particular, one such strategy used does not deliver an equilibrium configuration for the complete unsupported strip. Here we present our own systematic approach to the same problem for each of these models, with the ultimate goal of assessing the stability of flip-symmetric configurations. The presence of point-wise constraints considerably complicates the latter step. We obtain the first stability results for the problem, numerically demonstrating that such equilibria render the total potential energy a local minimum. Along the way we introduce a novel regularization for the singular Wunderlich model that delivers equilibria for complete strips having sufficiently narrow widths, which can then be tested for stability.

Stability Analysis of an Imperfect Slender Web Subjected to the Shear Load

2016 ◽  
Vol 837 ◽  
pp. 52-57
Author(s):  
Martin Psotny
Keyword(s):  
Stability Analysis ◽  
Potential Energy ◽  
Total Potential Energy ◽  
Iteration Algorithm ◽  
Buckling Mode ◽  
Total Potential ◽  
Nonlinear Equilibrium ◽  
The Stability ◽  
Ansys System ◽  
Raphson Iteration

The stability analysis of an imperfect slender web subjected to the shearing load is presented, a specialized code based on FEM has been created. The nonlinear finite element method equations are derived from the variational principle of minimum of total potential energy. To obtain the nonlinear equilibrium paths, the Newton-Raphson iteration algorithm is used. Corresponding levels of the total potential energy are defined. The peculiarities of the effects of the initial imperfections are investigated. Special attention is paid to the influence of imperfections on the post-critical buckling mode. Obtained results are compared with those gained using ANSYS system.

scholarly journals Buckling And Postbuckling Of An Imperfect Plate Subjected To The Shear Load

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
Martin Psotný
Keyword(s):  
Potential Energy ◽  
Total Potential Energy ◽  
Iteration Algorithm ◽  
Shear Load ◽  
Buckling Mode ◽  
Total Potential ◽  
Nonlinear Equilibrium ◽  
The Stability ◽  
Ansys System ◽  
Raphson Iteration

Abstract The stability analysis of an imperfect plate subjected to the shear load is presented. To solve this problem, a specialized computer program based on FEM has been created. The nonlinear finite element method equations are derived from the variational principle of minimum of total potential energy. To obtain the nonlinear equilibrium paths, the Newton-Raphson iteration algorithm is used. Corresponding levels of the total potential energy are defined. Special attention is paid to the influence of imperfections on the post-critical buckling mode. Obtained results are compared with those gained using ANSYS system.

scholarly journals Prediction of the Collapse Region Induced by a Concealed Karst Cave above a Deep Highway Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Fu Huang ◽  
Di Wang ◽  
Yuan Feng ◽  
Min Zhang
Keyword(s):  
Rock Mass ◽  
Karst Cave ◽  
Favorable Result ◽  
Safe Distance ◽  
Upper Bound Theorem ◽  
Analytical Expression ◽  
Highway Tunnel ◽  
Concealed Karst Cave ◽  
Collapse Region ◽  
Minimum Safe Distance

The presence of a concealed karst cave above a deep highway tunnel may cause the collapse of the rock mass between the karst cave and tunnel during excavation. Rock mass collapse threatens the safety of tunnel construction personnel. A prediction method of the collapse region induced by a concealed karst cave above a deep highway tunnel is proposed on the basis of the upper bound theorem of limit analysis. An analytical expression of the collapse surface is derived from the variational principle. Using the analytical expression of the collapse surface, the shapes of the collapse surfaces are plotted for different rock mass parameters. Moreover, the minimum safe distance between the karst cave and tunnel is defined, and the computational equation of the minimum safe distance is derived. The proposed method is applied in a highway tunnel excavated in a karst terrain as a case study. Based on geological survey report parameters, the shape of the collapse surface and the minimum safe distance between the karst cave and tunnel are obtained. Finally, the collapse surface of the rock mass provided by the proposed approach is compared with that provided by numerical simulation, and the favorable result comparison shows that the proposed method is valid.

Sign in / Sign up

Export Citation Format

Share Document