Shake table testing was performed to investigate the dynamic stability of a mid-dip bedding rock slope under frequent earthquakes. Then, numerical modelling was established to further study the slope dynamic stability...Shake table testing was performed to investigate the dynamic stability of a mid-dip bedding rock slope under frequent earthquakes. Then, numerical modelling was established to further study the slope dynamic stability under purely microseisms and the influence of five factors, including seismic amplitude, slope height, slope angle, strata inclination and strata thickness, were considered. The experimental results show that the natural frequency of the slope decreases and damping ratio increases as the earthquake loading times increase. The dynamic strength reduction method is adopted for the stability evaluation of the bedding rock slope in numerical simulation, and the slope stability decreases with the increase of seismic amplitude, increase of slope height, reduction of strata thickness and increase of slope angle. The failure mode of a mid-dip bedding rock slope in the shaking table test is integral slipping along the bedding surface with dipping tensile cracks at the slope rear edge going through the bedding surfaces. In the numerical simulation, the long-term stability of a mid-dip bedding slope is worst under frequent microseisms and the slope is at risk of integral sliding instability, whereas the slope rock mass is more broken than shown in the shaking table test. The research results are of practical significance to better understand the formation mechanism of reservoir landslides and prevent future landslide disasters.展开更多
In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equ...In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equations for atmosphere and sea motion, a three dimensional compact upwind scheme (CUWS) is constructed, as the basis of the DS-EDE. The DS-EDE satisfies the following condition of energy dynamic equilibrium (EDE): the total work of external forces on the region boundary is equal to the sum of the total effective variation of the kinetic energy and the energy dissipation in the average flow motion and the effective variation of the potential energy per unit time within the region of interest. It really reflects the basic mechanism of the action of external forces and dissipation in atmosphere and sea movement. Therefore, the DS-EDE developed in this paper is a suitable model for simulating long-term atmosphere and sea movement with forcing and dissipation.展开更多
Evaluation and prediction of the long-term behavior of abandoned mines have to consider complex interactions of different physical processes.The hydro-mechanical coupling plays an important role for potential short-an...Evaluation and prediction of the long-term behavior of abandoned mines have to consider complex interactions of different physical processes.The hydro-mechanical coupling plays an important role for potential short-and long-term environmental risks(e.g.surface subsidence,pollution of the biosphere,damage of the geological barrier,damage of groundwater regime).This work addresses challenges and key mechanisms in respect to longterm predictions for abandoned salt and potash mines and provides a general simulation concept.Exemplary,this concept is applied to a generic salt mine model characterized by hydro-mechanical coupling and visco-elasto as well as elasto-plastic material behavior.The concept considers time-depending rock mass and backfill material behavior.Long-lasting and large-scale fluid flow within solution-filled and backfilled cavities as well as a cavern due to creep induced convergence is simulated.A new coupling scheme between the numerical codes FLAC3D and Ansys Fluent is developed and employed for this purpose giving plausible and accurate results by efficient simulation duration.The presented workflow provides a step-by-step overview for assessing long-term safety of abandoned mines,starting with indication of main aspects determining the geomechanical and hydraulic pro-cesses followed by the exemplary model set-up,the choice of constitutive models,the simplification of the modelled mining process,the model calibration and the interpretation of the numerical results.Different model scenarios in respect to initial fluid saturation are simulated considering a partially saturated mine and a fully saturated mine,which leads to free fluid surface evolution up to the generation of excess of fluid pressure.展开更多
基金National Natural Science Foundation of China under Grant No. 41372356the College Cultivation Project of the National Natural Science Foundation of China under Grant No. 2018PY30+1 种基金the Basic Research and Frontier Exploration Project of Chongqing,China under Grant No. cstc2018jcyj A1597the Graduate Scientific Research and Innovation Foundation of Chongqing,China under Grant No. CYS18026。
文摘Shake table testing was performed to investigate the dynamic stability of a mid-dip bedding rock slope under frequent earthquakes. Then, numerical modelling was established to further study the slope dynamic stability under purely microseisms and the influence of five factors, including seismic amplitude, slope height, slope angle, strata inclination and strata thickness, were considered. The experimental results show that the natural frequency of the slope decreases and damping ratio increases as the earthquake loading times increase. The dynamic strength reduction method is adopted for the stability evaluation of the bedding rock slope in numerical simulation, and the slope stability decreases with the increase of seismic amplitude, increase of slope height, reduction of strata thickness and increase of slope angle. The failure mode of a mid-dip bedding rock slope in the shaking table test is integral slipping along the bedding surface with dipping tensile cracks at the slope rear edge going through the bedding surfaces. In the numerical simulation, the long-term stability of a mid-dip bedding slope is worst under frequent microseisms and the slope is at risk of integral sliding instability, whereas the slope rock mass is more broken than shown in the shaking table test. The research results are of practical significance to better understand the formation mechanism of reservoir landslides and prevent future landslide disasters.
基金This study was supported by China Institute for Radiation Protection,partly by State Key Laboratory of Numerical Modeling for Atmosphenc Sciences and Geophysical Fluid Dynamics.
文摘In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equations for atmosphere and sea motion, a three dimensional compact upwind scheme (CUWS) is constructed, as the basis of the DS-EDE. The DS-EDE satisfies the following condition of energy dynamic equilibrium (EDE): the total work of external forces on the region boundary is equal to the sum of the total effective variation of the kinetic energy and the energy dissipation in the average flow motion and the effective variation of the potential energy per unit time within the region of interest. It really reflects the basic mechanism of the action of external forces and dissipation in atmosphere and sea movement. Therefore, the DS-EDE developed in this paper is a suitable model for simulating long-term atmosphere and sea movement with forcing and dissipation.
文摘Evaluation and prediction of the long-term behavior of abandoned mines have to consider complex interactions of different physical processes.The hydro-mechanical coupling plays an important role for potential short-and long-term environmental risks(e.g.surface subsidence,pollution of the biosphere,damage of the geological barrier,damage of groundwater regime).This work addresses challenges and key mechanisms in respect to longterm predictions for abandoned salt and potash mines and provides a general simulation concept.Exemplary,this concept is applied to a generic salt mine model characterized by hydro-mechanical coupling and visco-elasto as well as elasto-plastic material behavior.The concept considers time-depending rock mass and backfill material behavior.Long-lasting and large-scale fluid flow within solution-filled and backfilled cavities as well as a cavern due to creep induced convergence is simulated.A new coupling scheme between the numerical codes FLAC3D and Ansys Fluent is developed and employed for this purpose giving plausible and accurate results by efficient simulation duration.The presented workflow provides a step-by-step overview for assessing long-term safety of abandoned mines,starting with indication of main aspects determining the geomechanical and hydraulic pro-cesses followed by the exemplary model set-up,the choice of constitutive models,the simplification of the modelled mining process,the model calibration and the interpretation of the numerical results.Different model scenarios in respect to initial fluid saturation are simulated considering a partially saturated mine and a fully saturated mine,which leads to free fluid surface evolution up to the generation of excess of fluid pressure.
