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Current and Recently Completed CCGE Projects
| AIF | Atlantic Innovation Fund program of ACOA |
|---|---|
| CODELCO | is a mining company in Chile |
| NSERC | Natural Sciences and Engineering Research Council |
| PDVSA | Petroleo de Venezuela Inc. |
| PCS | Potash Corporation of Saskatchewan |
| UdeM | Université de Moncton |
Integrated Monitoring and Analysis of Ground Subsidence at PCS Potash Mine in New Brunswick
A. Chrzanowski and A. Szostak-Chrzanowski
The research, initiated in 1989, continues to provide annual data on ground subsidence and horizontal movements at the Potash Corporation of Saskatchewan (PCS) - N.B. Division mine near Sussex, N.B. The annual surveys include precision terrestrial geodetic surveys with digital levels, robotic total stations and GPS covering the area of about 3 km x 15 km . The purpose of the study has been to enhance understanding of the deformation mechanism and provide data for the development of a ground subsidence prediction model by combining the geometrical analysis of the observed subsidence with the numerical model using the finite element method and the earlier developed software FEMMA. In 1998, a significant water inflow to the mine occurred followed by a development of a secondary subsidence basin The monitoring results help in localizing the source of the water inflow and allow for a better design of mitigative measures. The research continues.
[PCS - N.B. Division, NSERC, AIF]
Enhancement of ALERT System for Fully Automated Monitoring, Processing, and Visualization of Deformations
A. Chrzanowski
Research continues on the enhancement of the earlier developed ALERT software (see http://ccge.unb.ca) suite for fully automated monitoring, processing, and analysis of displacements. Recently, the following modules have been added:
- A module for performing a fully automatic least squares adjustment of networks of robotic total stations (RTSs).
- An Alarm module to provide for automatic warning system whenever the monitoring results would indicate that the pre-determined threshold values of deformation have been exceeded;
[AIF, ACA]
Development of a Hybrid (RTS/GPS/PL) System for Fully Automated Monitoring of High Walls in Large Open Pit Mines
A. Chrzanowski
An integration of robotic total stations (e.g. Leica TCA1800) with GPS and pseudolites, is being added to the ALERT deformation monitoring system (see http://ccge.unb.ca) to monitor stability of RTSs and control points in case when RTSs must be placed on unstable ground (e.g. on the bench walls in large open pit mines). The system is fully automated and adapted for continuous monitoring of displacements of large number of targets. Preliminary tests of a prototype RTS/GPS system augmented by Pseudolites (PL) have been performed in a large open pit mine of Highland Valley Copper Inc. in B.C., Canada. Modeling of the tropospheric differential corrections to GPS and PL observations is the main problem in the use of the hybrid system in open pit mines where large height differences between RTS locations are encountered. The use of PLs becomes useful when RTSs must be placed near the bottom of the open pit where GPS signals are obstructed. The research is in progress.
[NSERC, AIF, ACA]
Effects of Atmospheric Refraction on Continuous Monitoring of Displacements Using Robotic Total Stations (RTS)
A. Chrzanowski
Continuous direction measurements with RTSs, as with any other optical lines of sight, are strongly affected by the changeable atmospheric refraction. The magnitude of refraction is particularly large in the harsh environment of large open pit mines. Tests have been performed in large open pit mines in Chile (elevation 3000 m and very strong solar radiation) and in Western Canada. Diurnal changes of pointing due the changeable daytime/nighttime refraction may reach 200 mm over distances of 1.5 km. Mitigation methods are being developed to model the effects of refraction and to optimally design locations of RTSs and of control pints for continuous monitoring of displacements.
[NSERC, CODELCO, AIF, ACA]
Semi-Automated Monitoring of Structural Deformations with Reflectorless Total Stations
Adam Chrzanowski
A methodology and software are being developed for structural deformation monitoring in cases when placing of surveying markers (targets) on the walls of the structure is either impossible or uneconomical. The method uses automated reflectorless total stations (e.g. Leica TCRA 1201). The new software module for monitoring structural deformations is being added to the existing fully automated ALERT system (developed at CCGE) for automated data processing and visualization. The immediate need for the method is to monitor the deformation, stability, shape, and overall integrity of large tanks used in the storage of hazardous materials (e.g., oil, acids, etc.). Preliminary tests of the method have been conducted in PDVSA oil fields in Venezuela to monitor deformations of oil tanks.
[NSERC, PDVSA, ACA]
Modeling of Ground Subsidence in Oil Fields
A. Szostak-Chrzanowski, A. Chrzanowski, and E. Ortiz
A method of integrated analysis and prediction of ground subsidence in oil fields is being developed at the Canadian Centre for Geodetic Engineering. The method utilizes the in-situ data such as location and geometry of the oil reservoir, geology, pressure in oil wells, production data, and surface deformation monitoring results. The data is used in forward analysis of subsidence modeling based on the functions between production, change of pressure in underground oil reservoir and ground subsidence. In order to define the functions, empirical methods based on influence functions, and numerical method (finite element method) are being used based on the data obtained from PDVSA oil company. The immediate goal of the ongoing research is to develop a modeling for predicting ground subsidence along La Costa Oriental del Lago de Maracaibo (COLM) oil fields in Venezuela.
[NSERC, Zulia University in Venezuela]
Verification of Geotechnical Parameters of Large Dams
A. Szostak-Chrzanowski and M. Massiéra (Univ. de Moncton)
This project is a cooperative effort of the Canadian Centre for Geodetic Engineering and ?ole de Genie at Université de Moncton. A method is being developed to verify design parameters of large earthen dams through the integration of actual deformation monitoring surveys with the finite element modelling of expected deformations. Monitoring is important for a better and safer design of the future dams through the verification of the design parameters where the geotechnical parameters are of the highest In case when the area of a reservoir is located within the influence of active tectonic plates, the design of the monitoring surveys have to consider not only loading effects of the reservoir and gravitational settlement of the dams but also effects of earth crustal movements. Thus, in order to be able to discriminate between various factors affecting the integrity of the dams, the local dam monitoring schemes have to be supplemented by geodetic control of the whole area of the reservoir to control the stability of the ridge lines above the reservoir and must be connected to the existing regional network of monitoring of the earth crustal movements. The integrated method of the verification of the geotechnical parameters has been implemented at:
- Two large embankment dams of the Diamond Valley Lake (DVL) Project in California
- Zoned La Grande 4 (LG-$) embankment dam of La Grande Hydroelectric Complex (phase I)
- concrete face rockfill dams in Québec
Integrated Analysis of Large Embankment Dams
A. Szostak-Chrzanowski and M. Massiéra (Univ. de Moncton)
By comparing results of monitoring measurements with a deterministic (prediction) model of deformation, one may determine and explain causes of deformation in a case of unexpected behaviour of the investigated object and its surrounding. The deformation process can be simulated using, for example, the finite element method (FEM) with the hyperbolic model of the nonlinear behaviour of the material. Due to the uncertainty of the model parameters, careful monitoring of the dam and its surroundings are required in order to verify and enhance the model.The values calculated from FEM may be compared with measured values giving information on the actual behavior of the structure. The differences between predicted and measured values may be arising from the selection of wrong mechanical parameters or assumed loading and boundary conditions in the FEM model. In order to find the cause of the differences, several models may have to be analyzed for different loading conditions with verified parameters. The concept has been successfully implemented in the analyses of deformations at West and East embankment Dams of Diamond Valley Lake (DVL) Project in California , LG-4 embankment dam of La Grande Hydroelectric Complex located in northern Québec, Canada, and a Concrete Face Rockfill Dams located in Northern Québec. The research continues.
[NSERC, UdeM, AIF]
Continuum Mechanics as a Support for Deformation Monitoring, Analysis and Interpretation
A. Szostak-Chrzanowski, W. Prószynski*, and W. Gambin* (*Warsaw Technical University)
Recent developments in multidisciplinary approach to geodetic and geotechnical monitoring, deformation analysis, and physical interpretation of behaviour of man-made and natural structures calls for creation of technological and scientific base for communication between various sectors of engineering and geosciences. Earlier developed concepts of integrated monitoring and analysis of deformations call for geodetic engineers to become involved in the physical interpretation of structural and ground deformations. The continuum mechanics is proposed as the base of the communication. The creation of the base would lead to the increase of awareness and better understanding among geodetic engineers in using methods of continuum mechanics as applied to the design and interpretation of deformation measurements. Research continues.
[NSERC, KBN (Poland)]