applying a constrained adjustment with a fixed height at p. 13 and using the criterion for the presence of other stable points, p. 11 and p. 12 are obtained as stable, while p. 10 is determined to be unstable. From free network adjustment point 10 is with maximum displacement( Tab. 4). This point is removed, and the adjustment is performed only with points 11, 12 and 13. Applying this strategy of maximal and minimal displacements helps in detecting unstable points. Generally, the maximal displacement strategy may be represented as the process of sequentially removing the points with maximal displacements and readjusting the network. The minimal displacement strategy is the process of adding points to a preliminary defined stable datum and sequentially adjusting the network. The strategy of maximal and minimal minimum displacements is like the backward and forward strategy for finding stable points, used in deformation analysis [ 23 ]. The conclusions from the adjustment results are that point 10 with maximal displacements is the“ most unstable” and point 13 with minimal displacements is the“ most stable”. After removing point 10 the results obtained from adjustment only with points 11, 12 and 13 don ' t indicate any deformations. The strategy of“ minimal displacements” begins with points 11 and 13 – the points with minimal displacements into the network( tab. 4). The processing methodology involves adding point 10 and adjusting the network with points 10, 11 and 13. Later, the next step is to adjust the network with points 11, 12, and 13. Comparing the displacements of points 10 and 12 the point with less displacement is point 12. The adjustment made with points 13, 11 and 12 doesn’ t indicate any displacements into the network. The new stable datum is now points 13, 11 and 12. Adding point 10 and readjusting the network show that point 10 is unstable. An analysis of deformation measurements in mine surveying may be made by using the approach presented in [ 6 ]. The design and implementation of modern geotechnical equipment applied for dam monitoring may be found in [ 5 ].
2. CONCLUSIONS
The monitoring of terrain and structures is of great importance for preventing damage to the terrain and the collapse of engineering structures. Deformation analysis studies are progressing with new theories. Related studies in this area demonstrated that some of the methods of deformation analysis did not work. Based on scientific research, there is no definitive answer to the question of the most effective method for stable point analysis. Different methods may be effective depending on the number of points, network geometry, etc. For that reason, to find stable points in geodetic networks, several methods can be used, which leads to the concept of complex deformation analysis( CODA). The theoretical background for the analysis of the stability of points with the various criteria used in deformation analysis has been successfully accomplished using complex deformation analysis( CODA).
3. REFERENCES
1. Al-dami, H., M. Zheleznov, A Comparative Analysis of Methods for Calculating Stability of Benchmarks Used in the Russian Federation to Monitor Deformations of Engineering Structures to Ensure Sustainability, IOP Conf. Ser.: Earth Environ. Sci. 1232 012048, 2023.
2. Alsadik, B., Y. Al-Kanani, Displacement Computation of Mosul Dam by Using Free Geodetic Network Adjustment. Journal of engineering, Baghdad university, 2010.
3. Ambrožič, T., A. Mulahusic, N. Tuno, J. Topoljak, A. Hajdar, D. Kogoj, Deformation analysis with robust methods in geodetic nets. Geodetski Vestnik. 63. 163-178. 10.15292 / geodetskivestnik. 2019.02.163-178, 2019.
4. Ardalan, A., R. Esmaeili, 3-D deformation analysis via invariant geodetic observations, Geophysical Research Abstracts 5: 09615. EGS-EGU-EUG Joint Assembly Nice, France, April, 2003.
5. Attaouia, B., K. Chouicha, S. Kahlouche, G. Bachir, Multi-sensor data fusion with AI-RBFN in settlement surveillance of embankment dams: application to a rockfill dam in Algeria. J Civil Struct Health Monit( 2023). https:// doi. org / 10.1007 / s13349-023-00691-8, 2023.
6. Begnovska, M., R. Sirakov, Accuracy of mine surveying measurements in the research of geomechanical processes, Proceedings of the X International Geomechanics Conference, 19 – 23 September 2022, Varna, Bulgaria, 2022.
7. Blake, L., S.,( Ed.), Civil Engineer ' s Reference Book, 4th Edition, CRC Press, 1994.
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