Modeling of avalanches and landslides in mountain areas of tail deposits
Mathematical modeling of rock fall and landslide processes activated by seismic effects that pose a threat for the uranium tailings of Kyrgyzstan
Tech Area / Field
- INF-COM/High Performance Computing and Networking/Information and Communications
- INF-DAT/Data Storage and Peripherals/Information and Communications
- INF-SOF/Software/Information and Communications
- PHY-ANU/Atomic and Nuclear Physics/Physics
3 Approved without Funding
Institute of Physics, Kyrgyzstan, Bishkek
- NeurOK Software, LLC, USA, GA, Alpharetta\nLivermore Software Technology Corporation, USA, CA, Livermore\nBowling Green State University, USA, OH, Bowling Green
Project summaryUSSR’s mining of natural uranium and rear earths for many years in Kyrgyzstan had left huge amounts of radioactive waste in tailing dumps on the surface. The waste was usually dumped in populated areas on mountain sides, catchment basins, often directly on beds and flood-pains of trans-boundary rivers streaming down to the valleys of Central Asia. After the USSR has collapsed, most dumps remain out of technical supervision and control which poses a severe threat to the environment and public health.
Research into the environmental and health effects of the dumped radioactive waste is important from several standpoints. Not only the contamination of natural water with radioactive nuclides and other toxic substances needs in-depth investigation, but also the threat posed by destruction or disintegration of tailing dumps by such catastrophes as earthquakes and landslides. These extremes bring transboundary environmental consequences.
Now the processes involved in rock low-cycle deformation and fracture are simulated through step-by-step calculations for inelastic deformation kinetics by Finite Element Analysis (FEA) implemented in such codes as ANSYS, LS-DYNA, and others. Data on the initial state of rock (residual stresses) are usually absent. That is why they only simulate the stable behavior of rock, which is assumed independent of the initial state. A few first cycles are simulated for an arbitrary initial state (usually unstressed) and then their results are extrapolated to the rest of the planned or residual life. Strain characteristics in this case are defined in accord with the expected pattern of deformation. The authors of the proposal have identified basic shortcomings in this approach. It seems possible to overcome them if extend the existing methods and codes for step-by-step kinetic calculations with the direct analysis of asymptotic stable processes to determine conditions for the implementation of cyclic inelastic deformations (impact parameters) and do stable deformation kinetics calculations for specified impacts. A theoretical basis for this work comes from inelastic adaptability theory recently developed by A.O. Chernyavsky and O.F. Chernyavsky.
What will be done under the project is expected to help evaluate the level of seismic load which can damage uranium tailings along the Mailuu-Suu River and cause an environmental catastrophe. Project results will be used to formulate recommendations for risk mitigation.
The objective of the project
The objective of the project is to do numerical simulations to predict the effect of seismic activity on rock mass and seismically activated rock falling and sliding which may threaten to damage uranium tailing dumps along the Mailuu-Suu River in Kyrgyzstan.
Technical approaches and methodology
The project provides for investigation into cyclic inelastic deformation stability, using the underlying provisions of inelastic adaptability theory formulated by A.O. Chernyavsky and O.F. Chernyavsky [1-8]. The main feature of their method is a differentiated approach to processes of interest. The processes are classified with respect to two parameters: magnitude and increment of inelastic deformations per cycle. For stable processes this results in the identification of four types of deformation, which correspond to different deformation properties and their schematization, different effects of some factors and different consequences (fracture mechanisms). Stable cycles are analyzed with account for dilatation induced creep and stresses. Theorems of elastic and inelastic adaptability reduce design calculation problems to non-classical variational ones. Their statements and solution methods differ depending on the type of deformation, but all structures are treated using a universal approach based on the finite element analysis.
It is planned to take and analyze samples of water (wells, springs, rivers etc), soil (riverside), and bottom sediments within the Mailuu-Suu River basin. Samples will also be taken at control points far from uranium tailings to determine the background concentrations of radioactive nuclides and other substances. The samples will be analyzed using α- and γ- spectrometry, and other methods for heavy metals content determination.
Project research will be implemented with use of a method which was developed under ISTC Projects KR-072-97, KR-715 and KR-850, based on the phenomenon of natural separation of U-234 and U-238, discovered by V.V. Cherdyntsev and P.I. Chalov . The method makes it possible to determin a share of technogenic (man-caused) uranium in natural water.
The following results are expected:
1. A code package will be developed to directly simulate the stable inelastic states of arbitrary shaped rock mass subjected to low-cycle mechanical, thermal or dilatation impacts. The package will be able to work with FEA systems which allow calculations for inelastic deformation kinetics (ANSYS, LS-DYNA).
2. The method proposed will be verified and practical techniques will be developed for tracing waste migration with natural water.
3. An evaluation will be made on how the spatial distribution of radioactive nuclides and other accompanying toxicants can change if a catastrophe causes to damage uranium tailings along the Mailuu-Suu River in Kyrgyzstan.
Role of foreign collaborators
Interaction with collaborators will include
- participation in meetings, planning and establishing contacts with institutions of project interest;
- participation in joint workshops and conferences, joint publications and conference presentations;
- exchange of information and international certification, dissemination and commercialization of project results.
1. Collect and analyze information on the state of rock in the area of uranium tailings in the Mailuu-Suu River basin.
2. Develop a database for the spatial distributions of uranium, radium, radon and heavy metals, and physicochemical parameters of the study region.
3. State the problem and decide on the particular procedure of seismically activated land sliding modeling.
4. Develop a 3D code for modeling the stable inelastic states of rock mass.
5. Do comparative calculations by ANSYS, LS-DYNA and the developed code.
6. Prepare documentation for the developed code, publications and project deliverables.
The project adequately addresses ISTC objectives.
It provides for global research related to evaluation and further development of recommendations to prevent the unfavorable environmental and human health effects of hazardous technology.
It provides nuclear weapons experts with possibility to shift their emphasis to peaceful activity and its results can be used for power facilities, oil-and-gas production equipment and other facilities whose life spans tens of years.
It promotes international scientific contacts and its results will be presented to international conferences and published in international journals. The results can be used to develop national strength and safety standards for nuclear power plants, petrochemical, metallurgical and other equipment throughout the world.
It supports basic (inelastic adaptability theory) and applied (advanced prediction methods) research efforts aimed to ensure safety of potentially hazardous facilities.
It helps resolve national and international technical problems by giving an instrument for developing high-efficient technologies of billet forming and residual stress control.
The software package to be developed under the project can be used for commercial purposes, specifically for calculation work given by a client institution for outsourcing. It will be possible to build the design calculation code developed in other FEA codes such as ANSYS, LS-DYNA etc.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.