This study will give a contemporary method for Quality Assurance or as-build during the construction of a building in Sofia, R. Bulgaria by using High Definition Survey (HDS) or more known as terrestrial Laser Scanning. Analyses were done on concrete casted elements (Floors, Ceiling Slabs and Columns) for the first eight floors which were already constructed during the time of field measurements. As a reference - data are obtained from the original design in native AutoCAD format, while field data were acquired by using 3D laser Scanners and they are represented in a form of Point Cloud. All data (design and measured) are acquired in local coordinate system and were later georeferenced in to the already established object coordinate system. The study will show the workflow for data preparation, post processing, and the results from 3D Inspection and Analyses. All tasks were implemented by two survey crews within 10 working days (four days for field work and 6 days for post processing analyses and reporting). During the laser scanning a total of 3 679 440 634 points were surveyed form 368 stations. After the post processing the number of points was reduced to 2 515 520 148 with relative accuracy after registration of individual scan worlds of +/- 3-4 mm. The accuracy for the data transformation in to the object coordinate system is +/- 7.5 mm. In order to have better data visibility and understanding of the deformations and displacements casted concrete elements were inspected separately floor by floor where ceiling and floor slabs were inspected in 1D (Z direction) while columns were inspected in 2D - (XY) inspection for the position. Thus some will say that the results are within accuracy limits of the classical measuring techniques we should not forget the fact that the percentage of inspected elements/surfaces is more than 95%.

The analysis of the cracking of the rock massifs is an important stage in the process of their characterization, as this largely determines their mechanical behavior. This is the main reason the mining engineers, who are angaged with the analysis of rock massifs, to require a most detailed and reliable study of the cracks that have arisen in them. Metric characteristics, such as the direction and angle of collapse of the cracks, roughness and average distances between the individual cracks, are extremely important for the study of the structural disturbance of the massif. In the process of the metrics forming of these characteristics, a few of methods of measurement and graphical representation, different in nature and technological features, have become necessary. Through these traditional methods, it is very often not possible to obtain adequate quantitative data for the complete geomechanical characteristics of the rock mass and for the analysis of the mechanisms for its instability. Here, the effectiveness of the ground laser scanning in the study of the structural disturbance (direction and angle of decay of the cracks) and the area cracking coefficient of the rock mass has been experimentally proved. Through this technology the research of the structural disturbance of the rock massifs acquires new quantitative and qualitative dimensions. On the basis of an extremely detailed 3D model, even of hard-to-reach sections of the rock massif, a realistic clustering of cracks and prerequisites for adequate determination of the area cracking coefficient of the massif are created. Moreover, ground-based laser scanning data are an indisputable source of valuable information about rock surface roughness. For an object of the experiment, was selected part of a rock massif, which has well-developed, clearly visible cracks. The scan was performed, using a ground-based laser scanner “Scan Station 2” of the company “Leica”.

No abstract

No abstract

No abstract