Detecting the Deterioration of Building Facades Using Terrestrial Laser Scanning Technique

Al-Neshawy, Fahim; Pöntinen, Petteri; Erving, Anna; Salo, Panu; Heiska, Nina; Kukko, Antero; Kaartinen, Harri; Puttonen, Jari

doi:10.2749/222137808796106477

Cited by 4 publications

(4 citation statements)

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“…To detect bowing of marble cladding, Al-Neshawy et al [19] used the FARO LS 880HE80 scanner to achieve a sampling step of approximately 1 mm at a distance of 4.36m, in which the semantic distance error was ± 3mm The TLS based results showed the magnitudes to differ 1-2mm for convex bowing and 6-7mm for concave ones when compared to manual measurements, in which the bowing magnitude was expressed as a term of the measured value of bowing over the distance between the supports of the 950mm long marble panel. Olsen et al [6] detected structural damage of reinforced concrete beam-columns using TLS.…”

Section: Related Workmentioning

confidence: 99%

Crack detection limits in unit based masonry with terrestrial laser scanning

Laefer

Truong-Hong

Carr

et al. 2014

NDT & E International

101

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This paper presents the fundamental mathematics to determine the minimum crack width detectable with a terrestrial laser scanner in unit-based masonry. Orthogonal offset, interval scan angle, crack orientation, and crack depth are the main parameters. The theoretical work is benchmarked against laboratory tests using 4 samples with predesigned crack widths of 1-7mm scanned at orthogonal distances of 5.0-12.5m and at angles of 0˚-30˚. Results showed that absolute errors of crack width were mostly less than 1.37mm when the orthogonal distance varied 5.0-7.5m but significantly increased for greater distances. Orthogonal distance had a disproportionately negative effect compared to the scan angle.2

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Section: Related Workmentioning

confidence: 99%

Crack detection limits in unit based masonry with terrestrial laser scanning

Laefer

Truong-Hong

Carr

et al. 2014

NDT & E International

101

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“…Several studies have been carried out focusing on the use of terrestrial laser scanning (TLS) technology as an inspection approach including the application of TLS for health monitoring and the inspection of bridge structures [24,25]; condition monitoring and defect identification for historic structures and building facades [26,27]; checking concrete conditions [16,28]; and as-built modelling [25,29]. In a study of [24] TLS that was used in building damage inspection after an earthquake, the accuracy of the measurement was achieved at the millimetre level, a performance comparable with conventional methods like displacement transducers and inclinometers.…”

Section: Tls Systemmentioning

confidence: 99%

Installation Quality Inspection for High Formwork Using Terrestrial Laser Scanning Technology

et al. 2022

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Current inspection for installation quality of high formwork is conducted by site managers based on personal experience and intuition. This non-systematic inspection is laborious and it is difficult to provide accurate dimension measurements for high formwork. The study proposed a method that uses terrestrial laser scanning (TLS) technology to collect the full range measurements of a high formwork and develop a genetic algorithm (GA) optimized artificial neutral network (ANN) model to improve measurement accuracy. First, a small-scale high formwork model set was established in the lab for scanning. Then, the collected multi-scan data were registered in a common reference system, and RGB value and symmetry of the structure were used to extract poles and tubes of the model set, removing all irrelevant data. Third, all the cross points of poles and tubes were generated. Next, the model set positioned on the moving equipment was scanned at different specified locations in order to collect sufficient data to develop an GA-ANN model that can generate accurate estimates of the point coordinates so that the accuracy of the dimension measurements can be achieved at the millimetre level. Validation experiments were conducted both on another model set and a real high formwork. The successful applications suggest that the proposed method is superior to other common techniques for obtaining the required data necessary for accurately measuring the overall structure dimensions, regarding data accuracy, cost and time. The study proposed an effective method for installation quality inspection for high formwork, especially when the inspection cannot be properly operated due to cost factors associated with common inspection methods.

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“…Factors that influenced the accuracy of the results were also investigated. A similar study was conducted by Al-Neshawy et al, (2010) where laser scanners were used to determine the shape of marble façade panels that have become concave or convex due to deterioration. Both of these flatness studies were developed with the assumption that the area of interest is perfectly flat.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Methods Used for Detecting Unknown Structural Elements in Three-dimensional Point Clouds

Yeung¹,

Nahangi²,

Shahtaheri³

et al. 2014

Construction Research Congress 2014

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Three dimensional (3D) imaging technologies, in particular 3D laser scanners, are becoming more accessible and more accurate. These advances are providing engineers and architects with vast quantities of raw, geometric data. While this data is visually appealing and intuitive to the human eye, it contains very little meaning beyond that. The research presented in this article presents and compares methods for attributing meaning to dense 3D point clouds. Two of the methods developed and presented utilize 2D and 3D Hough transforms to represent the points as lines and planes. The third method uses point segmentation techniques to group points belonging to the same plane. The initial focus is on structural steel systems and connections modeling for analysis of re-use. The advantages and disadvantages of each method are outlined, and each method is evaluated for its potential to provide engineers and architects with useful and meaningful point clouds from 3D laser scanners. The point segmentation techniques exhibit the most potential by allowing for the location and orientation of any surface to be identified.

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Detecting the Deterioration of Building Facades Using Terrestrial Laser Scanning Technique

Cited by 4 publications

References 0 publications

Crack detection limits in unit based masonry with terrestrial laser scanning

Crack detection limits in unit based masonry with terrestrial laser scanning

Installation Quality Inspection for High Formwork Using Terrestrial Laser Scanning Technology

Comparison of Methods Used for Detecting Unknown Structural Elements in Three-dimensional Point Clouds

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