ارزیابی کاربرد تکنیک TDR در بررسی‌های زمین‌شناسی مهندسی– مطالعه موردی سد داریان

نوع مقاله: مقاله پژوهشی

نویسندگان

1 استاد، گروه زمین‌شناسی کاربردی، دانشکده علوم زمین، دانشگاه خوارزمی تهران، ایران

2 دانشجوی دکترا، گروه زمین‌شناسی کاربردی، دانشکده علوم زمین، دانشگاه خوارزمی تهران، ایران

3 استادیار، گروه علوم و مهندسی خاک، دانشگاه کردستان، ایران

چکیده

با توجه به گسترش و توسعه کاربرد تکنولوژی در زمین‎شناسی مهندسی، ژئوتکنیک، مکانیک خاک و مکانیک سنگ، هر روزه امکان استفاده از روش‌های جدیدتر، سریع‌تر و ارزان‌تر در این زمینه‌ها فراهم می‌شود. یکی از این روش‌ها تکنولوژی TDR است. این تکنولوژی در ابتدا به وسیله صنعت مخابرات و برق برای تعیین محل عیب کابل‌ها توسعه پیدا کرد. رادار یک مثال ابتدایی از TDR است. اساس این تکنولوژی ارسال یک پالس کوتاه انرژی است که در اثر برخورد با برخی آنومالی‎ها منعکس می‌شود. محل این آنومالی‎ها در صورتی قابل تعیین است که سرعت و جهت پالس مشخص باشد. یک سیستم TDR از یک دریافت‌کننده و تولید‌کننده موج رادار (الکترومغناطیس)، یک خط انتقال و موج‌بر تشکیل شده است. پالس الکترومغناطیس تولید شده از درون کابل هادی به سمت موج‌بر حرکت می‌کند و از طریق موج‌بر وارد محیط تحت آزمایش می‌شود. در پژوهش حاضر از این تکنیک در سد داریان و در چاه مشاهده‌ای شماره 10 برای تعییین سطح آب زیرزمینی استفاده شده است. TDR به خوبی قادر به تشخیص سطح مشترک آب- هوا بوده و نتایج حاصل بر داده‌های اندازه‌گیری شده با روش‌های سنتی منطبق است. همچنین در یکی از ترانشه‌های مستعد لغزش در سد داریان کابل کواکسیال به عنوان سنسور TDR نصب شد. نتایج نشان دادند که TDR زون‌های برشی و کششی کابل را که در نتیجه حرکات زمین به وجود آمده‌اند با موفقیت شناسایی می‌کند. در نهایت از آنجا که پردازش دستی داده‌های TDR بسیار مشکل و نیازمند دقت و زمان زیادی است؛ روشی را برای پردازش کامپیوتری این داده‌ها ابداع شد.

کلیدواژه‌ها


عنوان مقاله [English]

Evaluation of TDR applications in engineering geological investigations -case study on Darian dam

نویسندگان [English]

  • S. M. Fatemi Aghda 1
  • K. GanjaliPour 2
  • K. Nabiollahi 3
1 Professor, Department of applied Geology, Faculty of Geological Science, Kharazmi University, Tehran, Iran.
2 PhD student, Department of applied Geology, Faculty of Geological Science, Kharazmi University, Tehran, Iran
3 Assistant Professor, Department of Soil Science and Engineering, Faculty of Agricultural Science, University of Kurdistan, Sanandaj, Iran
چکیده [English]

Due to the expansion and application of technology in soil and rock mechanics, engineering geology and geotechnics, it is possible to use newer, faster and cheaper methods in these fields every day. TDR technology is one of these methods. This technology has been developed by the telecommunication and electricity industry to determine the location of cable faults. The radar is a prime example of the TDR. The basis of this technology is the sending of a short pulse of energy (electromagnetic pulse) that is reflected in the collision with some anomalies. The point location of these anomalies can be determined if the velocity and direction of the pulse can be determined. The electromagnetic pulse reaches the waveguide through the conductor cable and enters the test environment. In this research, this method was used to determine the groundwater level in the Darian dam. The TDR has the ability to detect the air-water interface, and the reported results are consistent with the measured data using traditional methods. Also in one of the situations that are prone to slide, coaxial cable was installed as TDR sensor. The results showed that the TDR recognizes the shearing and stretching zones in the cable as the result of the ground movement successfully. Finally, since manual processing of TDR data was very difficult and requires high accuracy and time, a method for computer processing of this data was provided by the authors.

کلیدواژه‌ها [English]

  • TDR
  • Reflection coefficient
  • Water Table
  • Electromagnetic pulse
  • Engineering geology

Bishop, J., Pommerenke, D. and Chen, G., 2011- A rapid-acquisition electrical time-domain reflectometer for dynamic structure analysis, IEEE Trans. Instrum. Meas. 60 (2), 655–661.
Cataldo, A., Cannazza, G., Benedetto, E. D. and Giaquinto, N., 2012- Experimental validation of TDR-based system for measuring leak distances in buried metal pipes. Journal of Progress in Electromagnetics Research, Vol. 132, 71-90.
Cataldo, A., Cannazza, G., Benedetto, E. D., Giaquinto, N. and Savino, M., 2013-  An inverse validation for detecting pipe leaks with a TDR  based method” 4th Imeko TC19 Symposium on Environmental Instrumentation and Measurements Protecting Environment, Climate Changes and Pollution Control, Lecce, Italy.
Cataldo, A., Catarinucci, L., Tarricone, L., Attivissimo, F. and Piuzzi, E., 2009a- A combined TD-FD method for enhanced reflectometry measurements in liquid quality monitoring. IEEE Transactions on Instrumentation and Measurement, Vol. 58, No. 10, 3534-3543.
Cataldo, A., Monti, G., De Benedetto, E., Cannazza, G. and Tarricone, L., 2009b- A noninvasive resonance-based method for moisture content evaluation through micro strip antennas. IEEE Transactions on Instrumentation and Measurement, Vol. 58, No. 5, 1420-1426.
Cataldo, A., Monti, G., De Benedetto, E., Cannazza, G. and Tarricone, L., 2008- A non-invasive approach for moisture measurements through patch antennas," Proc. IEEE Int. Instrum. Meas. Technol. Conf., 1012-1015, Victoria, BC.
Cataldo, A., Piuzzi, E., Cannazza, G. and De Benedetto, E., 2007- Dielectric spectroscopy of liquids through a combined approach: evaluation of the metrological performance and feasibility study on vegetable oils. IEEE Sensors Journal, Vol. 9, No. 10, 1226-1233.
Cataldo, A., Piuzzi, E., Cannazza, G. and De Benedetto, E., 2012- Classification and adulteration control of vegetable oils based on microwave e reflectometry analysis.  Journal of Food Engineering, Vol. 112, No. 4, 338-345.
Cataldo, A., Piuzzi, E., Cannazza, G., De Benedetto, E. and Tarricone, L., 2010- Quality and anti-adulteration control of vegetable oils through microwave dielectric spectroscopy.  Measurement,Vol. 43, No. 8, 1031-1039.
Dowding, C. H. and Huang, F. C., 1994- Ground water pressure measurements with time domain reflectometry. Proceedings, symposium and workshop on time domain rejlectometry in environmental, infrastructure, and mining applications. Northwestern University, Evanston, IL. Bureau of Mines, Special Publication, 19-94, 247-258.
Dowding, C., Huang, F. and McComb, P., 1996- Water pressure measurement with time domain reflectometry cables. Geotechnical Testing Journal, 19(1), 58-64.
Dowding, C. H., Su, M. B. and O'Connor, K. M., 1988- Principles of time domain reflectometery applied to measurement of rock mass deformation. Int. J. Rock Mech. Min. Sci. Geomech. Abstr, 25, 287-297.
Fellner-Feldegg, H., 1969- The measurement of dielectrics in the time domain. The Journal of Physical Chemistry 73 (3), 616-623.
Grifiths, L. A., Parakh, R., Furse, C. and Baker, B., 2006- The invisible fray: A critical analysis of the use of reflectometry for fraylocation. IEEE Sensors Journal, Vol. 6, No. 3, 697-706.
Hager, III, N. E., 1994- Broadband time-domain-reflectometry dielectric spectroscopy using variable-time-scale sampling. Review of Scientific Instruments, Vol. 64, No. 4, 887{891.
Kane, W. F. and Beck, T. J., 1996- An alternative monitoring system for unstable slopes. Geotechnical news. 143:24-26.
Mikkelsen, P. E., 1996- Field instrumentation. Landslides. Investigation and mitigation. Washington: Transportation Research Board.
Moradi, G. and Abdipour, A., 2007- Measuring the permittivity of dielectric materials using STDR approach. Progress in Electromagnetics Research, Vol. 77, 357-365.
Nicholson, G., Powell, A., J. F. and O'Connor, K. M., 1997- Monitoring Groundwater Levels Using a Time-Domain Reflectometry (TDR) Pulser. US Army Corps of Engineers Waterways Experiment Station, Technical Report CPAR-GL-97-
Nissen, H. and Moldrup, P., 1995- Theoretical background for the TDR methodology," Proceedings, Time Domain Reflectometry Applications in Soil Science. SP Report No. 11, Danish Institute of Plant and Soil Science, 9-24.
Nozaki, R. and Bose, T. K., 1990- Broadband complex permittivity measurements by time-domain spectroscopy," IEEE Trans. Instrum. Meas., Vol. 39, No. 6, 945-951.
O'Connor, K. M. and Dowding, C. H., 1999- GeoMeasurements by Pulsing TDR Cables and Probes. CRC Press, UK, Jan..
Piuzzi, E., Cataldo, A. and Catarinucci, L., 2009- Enhanced reflectometry measurements of permittivities and levels in layered petrochemical liquids using an `in-situ' coaxial probe,” Measurement, Vol. 42, No. 5, 685-696.
Ross, G. F., 1974- Apparatus and method for measuring the level of a contained liquid," U.S. Patent No. 3,832,900.
Ross, G. F., 1976- Apparatus and method for sensing a liquid with a single wire transmission line," U.S. Patent No. 3,995,212.
Schuet, S., Timucin, D. and Wheeler, K., 2011- A model-based probabilistic inversion framework for characterizing wire fault detection using TDR. IEEE Transactions on Instrumentationand Measurement, Vol. 60, No. 5, 1654-1663.
Topp, G., Davis, J. and Annan, A., 1980- Electromagnetic determination of soil water content," Water Resources Research, 16(3), 574-582.