Robert Gradka

Ground deformations induced by underground mining significantly affect the geometric condition and serviceability of buildings located in mining areas. Conventional assessments are commonly based on ground deformation indicators, which do not necessarily reflect the actual structural response. This study presents a terrestrial laser scanning (TLS)-based methodology for assessing the three-dimensional deformation of an eleven-storey residential building located in the Legnica–Głogów Copper District (LGCD), Poland. The analysis was performed using a high-density point cloud acquired from ten scanning positions. Following registration and filtering, building geometry was reconstructed and corner positions were determined from 123 horizontal cross-sections. Horizontal displacements, tilt profiles, and rotation about the vertical axis were subsequently analysed within a local coordinate system. The results revealed pronounced spatial variability in both displacement magnitude and direction. The maximum horizontal displacement reached approximately 0.18 m, corresponding to a local tilt of 5.9 mm/m. Corner displacements at the highest common observation level ranged from 8.6 mm to 178.3 mm, indicating that the observed geometry is inconsistent with a simple rigid-body model subjected to uniform tilting. Analysis of geometric changes with height further identified an overall increase in torsional rotation with height, accompanied by local variations. Comparison of TLS-derived geometry with a theoretical mining-induced ground deformation model showed that the measured structural response does not directly reproduce the underlying ground deformation pattern. The largest discrepancies occurred along the building longitudinal axis, indicating that structural stiffness and soil–foundation–structure interaction significantly modify the transfer of ground movements to the superstructure. These results demonstrate the capability of TLS for detailed assessment of mining-affected buildings and provide quantitative insight into the relationship between ground deformation and actual structural response.

This study presents a hybrid geodetic validation framework for assessing the geometric consistency of the axis of a steel lattice transmission tower determined from terrestrial laser scanning (TLS) data using an independently established tachymetric reference. Unlike previous investigations that focused on the influence of TLS scanner characteristics, registration strategies, or internal consistency of TLS-derived axes, the proposed approach introduces an external geodetic reference, enabling direct external assessment of TLS-based geometric axis estimation. The reference axis was determined at fourteen height levels, while the TLS axis was estimated from horizontal cross-sections of a point cloud acquired from multiple scanning stations and registered using a cloud-to-cloud method without control points. To enable direct comparison, both datasets were transformed into a common reference system using a seven-parameter Helmert transformation. The transformation was applied solely to remove differences between the independent local coordinate systems prior to the geometric comparison. Axis consistency was evaluated using residual vectors and three-dimensional distances between corresponding points. The mean deviation was 0.031 m, the RMS value was 0.033 m, and the maximum deviation reached 0.078 m. Larger discrepancies occurred predominantly in the upper sections of the structure, in a pattern consistent with the combined influence of TLS registration uncertainty, non-uniform point-cloud coverage, and local geometric conditions. A comparison of TLS axis estimators (centroid, LS-R regression, and PCA) showed that PCA produced an RMS value close to that of the centroid estimator, whereas LS-R produced a higher RMS value; the maximum deviation was lowest for the centroid estimator and highest for PCA. Regression analysis revealed a statistically significant linear trend in the X direction (p = 0.019), indicating residual systematic geometric drift after coordinate-system integration. The obtained discrepancies should be interpreted in the context of a rapid engineering TLS workflow performed without registration targets or a control network, rather than as the intrinsic accuracy of the TLS instrument itself. The proposed hybrid validation framework provides an objective quality-control methodology for evaluating TLS-derived geometric axes against independent geodetic observations and may support reliability assessment of TLS-based inventories and deformation monitoring of slender engineering structures.

Geometric monitoring of slender support structures, particularly steel lattice transmission towers, is a critical component of power infrastructure diagnostics. Such structures are susceptible to environmental influences and long-term deformation processes, which necessitates precise assessment of their geometric axis. The aim of this study was to evaluate the influence of the terrestrial laser scanning (TLS) scanner class and point cloud registration strategy on the determination of the geometric axis of a steel high-voltage lattice transmission tower (hereafter LTT). Unlike previous studies focused primarily on TLS-based axis reconstruction, this work introduces a comparative assessment of registration strategies, an error propagation model, and the proposed Axis Drift Index (ADI) as quantitative indicators of axis stability. The analysis was based on data obtained using a tachymetric method (reference), a compact scanner (Leica BLK360), and a survey-grade scanner (Riegl VZ-400i). The comparison included planimetric axis deviation, consistency of deformation direction, variation in results with height, and the influence of registration quality. The results show that TLS measurements performed using a survey-grade scanner and target-based registration exhibit high agreement with tachymetric results. In contrast, cloud-to-cloud registration without a stable reference framework leads to cumulative errors and instability of the reconstructed axis, particularly in the upper parts of the structure. The observed deviations in the BLK360 dataset were dominated by registration-related geometric instability rather than unequivocal structural deformation signals. The findings indicate that the accuracy of geometric axis determination in slender structures is governed more by the adopted point cloud registration strategy than by the scanner class itself. The proposed ADI parameter and linear error propagation model additionally enabled a quantitative assessment of geometric consistency with height. From an engineering perspective, this highlights the importance of stable reference systems and appropriate survey design in high-precision TLS applications. Although the study was conducted on a single lattice tower, the results provide practical insight into the reliability of TLS workflows for slender structures characterized by discontinuous geometry and high sensitivity to registration errors.

While geometric accuracy, expressed as Root Mean Square Error (RMSE), serves as the primary benchmark in Unmanned Aerial Vehicle (UAV) photogrammetry, thematic consistency between planar (2D) and volumetric (3D) deliverables remains insufficiently quantified. This study investigates the "accuracy paradox" questioning the assumption that high georeferencing precision inherently ensures thematic reliability. Research was conducted over a 22.6-hectare rural site in southern Poland. Using a UAV photogrammetric model (3 cm Ground Sampling Distance (GSD), 0.136 m RMSE), independent manual land-use delineations were performed on a high-resolution orthomosaic and a dense point cloud. To evaluate discrepancies, the Convergence Index (CI) was introduced, quantifying relative area differences between representations. Results indicate a total thematic discrepancy of 2.4% (0.5419 ha). However, errors were non-uniformly distributed: infrastructural classes showed near-perfect agreement (CI < 1%), whereas forested areas exhibited CI values exceeding 6%. 2D projections tended to overestimate forested areas, creating a false horizontal expansion of tree canopies. Furthermore, a strong negative correlation (Pearson r = –0.95, p < 0.001) was found between image overlap redundancy and thematic divergence. The study concludes that object morphology and 3D reconstruction completeness exert a more significant impact on inventory reliability than nominal georeferencing accuracy. For high-precision cadastral and environmental surveying, integrating 3D point clouds may be necessary, particularly in vegetation-dominated environments, to mitigate systematic distortions inherent in 2D orthomosaic projections.

Geometric monitoring of slender structures in power transmission infrastructure, particularly steel lattice towers of high-voltage lines, is an important engineering surveying task due to their susceptibility to environmental loads and their role in operational safety. This study compares the determination of the geometric axes of lattice transmission towers using classical tachymetric measurements and terrestrial laser scanning (TLS) performed with a compact Leica BLK360 scanner. The objective was to assess the consistency of these two methods in determining planimetric axis deviation, and to evaluate how the quality of point cloud registration impacts the results. The analysis was carried out at fourteen height levels, with deviations referred to the lowest measurement level. The TLS data were evaluated using registration quality parameters (overlap, strength, cloud-to-cloud, and global bundle error) obtained in Cyclone REGISTER 360 PLUS. Registration was performed in cloud-to-cloud mode without the use of control points. The results revealed significant discrepancies between the two methods, with local deviations exceeding 100 mm. The maximum planimetric axis deviation derived from TLS reached 140 mm, whereas the corresponding value obtained from tachymetry did not exceed 44 mm at the same inclination. Increasing differences were observed in the upper parts of the structure. These findings suggest that TLS measurements taken without stable geometric control cannot be relied upon to accurately assess axis deviation. In practice, combining the geometric stability of tachymetric measurements with the spatial completeness of TLS data offers the most effective solution for precise axis evaluation and comprehensive geometric documentation.

The article presents an analysis and comparison of geodetic methods used for the measurement and monitoring of slender structures such as chimneys, towers, cooling towers, and power line poles. Due to their slender geometry and considerable height, these structures are highly sensitive to environmental influences, including wind, temperature variations, and ground settlement. The study discusses the evolution of measurement techniques – from classical tacheometry and levelling, through satellite-based GPS and GNSS systems, to modern terrestrial laser scanning (TLS) and digital photogrammetry. Recent research indicates integrating multiple surveying methods, known as a hybrid approach, guarantees improved accuracy and reliability of measurement results. The measurement of verticality of the Wrocław Iglica, a representative slender structure, is an example of the use of the described methods. Due to its geometry and the conditions in the field, a tacheometric survey was conducted to determine vertical axis deviations under different sunlight conditions. The results confirmed noticeable deflections of the structure’s top throughout the day, demonstrating the influence of thermal factors on its stability. The analysis of both literature and measurement shows that the most effective approach to monitoring slender structures is the integration of data from various geodetic techniques. Such hybrid monitoring ensures a comprehensive assessment of the structural stability and durability of slender constructions over time. The results highlight the importance of continuous geodetic monitoring as a key factor in ensuring the safety and reliability of engineering structures.

Many factors cause the deformation of slender structures, such as the weather conditions that significantly affect their geometry. Surveys of such structures are critical for deformation monitoring and, therefore, general safety. Modern surveying methods like electronic tacheometry (ET), Global Navigation Satellite Systems (GNSS), laser scanning (LiDAR, terrestrial (TLS) and mobile (MLS)), and Unmanned Aerial Vehicles (UAVs) provide means for accurate and effective monitoring. Integrating surveying technologies paves the way for an exhaustive approach to slender structure monitoring and provides accurate data to detect deformation and intervene early. Electricity transmission poles exemplify such structures. The poles need to be monitored regularly to ensure operating stability and safety. The article reports a survey of tubular steel pole deflection angles at various times of the year and under various weather conditions. The surveys were accompanied by temperature measurements and a solar irradiance analysis. The maximum horizontal deflection of the pole top was found to be approximately 27 cm over a single sunny day, highlighting the dynamic nature of solar influence. The analyses yielded conclusions regarding measurements of slender steel structures. Specifically, the study confirmed that solar irradiance can cause short-term deflections of the pole top by up to 27 cm in a single day, and uncertainty increases proportionally with structural dynamics. Consequently, recording precise time and weather conditions during surveys is essential to improve rapid, time-constrained measurement accuracy and the operational safety assessment of slender steel structures. This should improve the measurement accuracy and operational safety of slender steel structures.

This paper presents the results of laboratory research regarding the influence of the structure and color of decorative renders on the accuracy of measurements conducted using Leica ScanStation P40 terrestrial laser scanning (TLS). The study examined whether and how differences in render structure and color (brightness) affect the quality of data acquired via TLS. The color and brightness measurements of the test fields were performed using a flatbed scanner. The RGB color and luminance analysis of the test fields were conducted using the software “ImageJ” version 1.54g. The measurements were conducted for light-colored renders (average brightness from 143 to 243). The research found no clear relationship established between the type and color of render and the accuracy of laser scanning. The results indicate increased measurement dispersion with decreasing render brightness. It was found that the standard deviation of distance measurements for Scratched-type renders is approximately 26% higher than for Roughcast-type render.

Pracy przedstawiono trendy dotyczące opadów,grubości i czasu zalegania pokrywy śnieżnej, silnych wiatrów, długościokresu wegetacyjnego, średnich oraz ekstremalnych wartościtemperatury powietrza dla obszaru Polski. Na podstawiedanych Głównego Urzędu Nadzoru Budowlanego (GUNB) z lat2006–2023 przeanalizowano, w jakim stopniu ekstremalne zjawiskaatmosferyczne przyczyniły się do katastrof obiektów budowlanychw Polsce.

W pracy przedstawiono analizę wpływu zmianyklimatu na obiekty budowlane. Omówiono wyzwania stojąceprzed konstruktorami w zakresie zmieniających się obciążeńwiatrem, śniegiem, zwiększającym się wpływem ekstremalnychtemperatur, intensywnych opadów, powodzi oraz suszy na obiektybudowlane i ich otoczenie. Wskazano działania, jakie należypodjąć w projektowaniu, budowie oraz utrzymaniu obiektówbudowlanych w celu minimalizacji negatywnego wpływu zmianyklimatu. Podkreślono konieczność ciągłego dostosowywanianorm projektowych do nowych warunków klimatycznych,stosowania materiałów i rozwiązań odpornych na ekstremalnewarunki atmosferyczne, zwiększenia kontroli technicznej obiektówjuż istniejących