scholarly journals Comparison of Non-Destructive Techniques for Technological Bridge Deflection Testing

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1908 ◽  
Author(s):  
Jacek Kwiatkowski ◽  
Wojciech Anigacz ◽  
Damian Beben
Keyword(s):  
Laser Scanning ◽  
Reference Data ◽  
Digital Camera ◽  
Suspension Bridge ◽  
Dynamic Loads ◽  
Belt Conveyor ◽  
Static Loads ◽  
Measuring Techniques ◽  
Non Destructive ◽  
Testing Range

This paper presents a comparison and assessment of usefulness of various measuring techniques (terrestrial laser scanning (TLS), tachymetry, photogrammetry) applied to establish the behavior of a suspension bridge under different load scenarios. The applied techniques were examined on the bridge with a 165 m span. The tested structure works as the technological bridge for a belt conveyor linking a lime mine and cement plant. The testing range consisted of conducting the non-contact measuring of the bridge and cable displacements under dynamic loads (during the belt conveyor movement—normal service loads) and static loads (while stopped). Tachymetric surveys were carried out using a precise total station (to obtain the reference data). A Canon 750D digital camera was applied in the photogrammetry technique. FARO Focus 3D and Trimble TX8 scanners were employed for the TLS measuring. The obtained results are especially important for bridge inspectors and managers who can use the non-contact measurements of serviced structures.

scholarly journals A Case Study on the Noncontact Inventory of the Oldest European Cast-iron Bridge Using Terrestrial Laser Scanning and Photogrammetric Techniques

2020 ◽  
Vol 12 (17) ◽  
pp. 2745 ◽  
Author(s):  
Jacek Kwiatkowski ◽  
Wojciech Anigacz ◽  
Damian Beben
Keyword(s):  
Cast Iron ◽  
Laser Scanning ◽  
Reference Data ◽  
Three Dimensional ◽  
Terrestrial Laser Scanning ◽  
Suspension Bridge ◽  
Three Dimensional Model ◽  
Survey Techniques ◽  
Survey Results

Conventional measurement technologies of transportation infrastructures consist of discrete surveys which can be inconvenient in practice. Furthermore, data obtained using these methods are restricted to several points (or elements) placed on the observed structures. Modern survey techniques—for example, terrestrial laser scanning (TLS) and photogrammetric—allow for the surveying of quasi-continuous surfaces of examined structures. The examined object is an historic cast-iron suspension bridge in Ozimek (south of Poland). The bridge was constructed in 1825–1827 and constitutes the oldest European bridge of this type. The surveys were conducted using TLS and digital photogrammetric techniques. The data obtained were compared with traditional survey results (reference data) and the project. The achieved effects of the measurements show that the discrepancies between the applied techniques (TLS and photogrammetry) and reference methods varied only within several millimeters and can be regarded as satisfactory. Better compliance was obtained for TLS than photogrammetry. The main benefits of the applied techniques include reducing time in the field and obtaining a three-dimensional model of the structure that has satisfactory accuracy.

Assessment of automatic segmentation accuracy with various point cloud density

2020 ◽  
Vol 961 (7) ◽  
pp. 47-55
Author(s):  
A.G. Yunusov ◽  
A.J. Jdeed ◽  
N.S. Begliarov ◽  
M.A. Elshewy
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Reference Data ◽  
Automatic Segmentation ◽  
Geometric Accuracy ◽  
Segmentation Method ◽  
Segmentation Methods ◽  
Segmentation Accuracy ◽  
Number Of Segments ◽  
Cloud Density

Laser scanning is considered as one of the most useful and fast technologies for modelling. On the other hand, the size of scan results can vary from hundreds to several million points. As a result, the large volume of the obtained clouds leads to complication at processing the results and increases the time costs. One way to reduce the volume of a point cloud is segmentation, which reduces the amount of data from several million points to a limited number of segments. In this article, we evaluated effect on the performance, the accuracy of various segmentation methods and the geometric accuracy of the obtained models at density changes taking into account the processing time. The results of our experiment were compared with reference data in a form of comparative analysis. As a conclusion, some recommendations for choosing the best segmentation method were proposed.

The Mechanical Properties Comparative Analysis for Socked and Non-Socketed Composite Pile

2014 ◽  
Vol 1061-1062 ◽  
pp. 748-750
Author(s):  
Heng Chen ◽  
Ke Sheng Ma
Keyword(s):  
Mechanical Properties ◽  
Comparative Analysis ◽  
Seismic Performance ◽  
Dynamic Loads ◽  
Vertical Load ◽  
Interlayer Thickness ◽  
Static Loads ◽  
Soil Stress ◽  
Composite Pile ◽  
Static And Dynamic Loads

For socked and non-socketed piles in the different mechanical behavior under static and dynamic loads, the paper use ABAQUS to model, simulate the pile , the soil interlayer thickness between the bottom of the pile and bedrock are 2m, 4m under vertical load and Earthquake, cushion cap, pile and pile soil stress situation found non-socketed piles when the soil interlayer thickness within a certain range, the composite pile small subside under dynamic, static loads, the non-socketed piles can better take advantage of the pile soil has a good seismic performance in the earthquake.

The Specific Characteristics of Shock and Blast Impacts on Construction Sites

2021 ◽  
pp. 81-88
Author(s):  
A.A. Komarov ◽  
Keyword(s):  
Dynamic Load ◽  
Static Load ◽  
Dynamic Loads ◽  
Potential Hazard ◽  
Construction Sites ◽  
Static Loads ◽  
Equivalent Static Loads ◽  
Plane Crash ◽  
Nuclear Plants ◽  
The Impact

The practices of hazardous and unique facilities’ construction imply that specific attention is paid to the issues of safety. Threats associated with crash impacts caused by moving cars or planes are considered. To ensure safety of these construction sites it is required to know the potential dynamic loads and their destructive capacity. This article considers the methodology of reducing dynamic loads associated with impacts caused by moving collapsing solids and blast loads to equivalent static loads. It is demonstrated that practically used methods of reduction of dynamic loads to static loads are based in schematization only of the positive phase of a dynamic load in a triangle forms are not always correct and true. The historical roots of this approach which is not correct nowadays are shown; such approach considered a detonation explosion as a source of dynamic load, including TNT and even a nuclear weapon. Application of the existing practices of reduction of dynamic load to static load for accidental explosions in the atmosphere that occur in deflagration mode with a significant vacuumization phase may cause crucial distortion of predicted loads for the construction sites. This circumstance may become a matter of specific importance at calculations of potential hazard of impacts and explosions in unique units — for instance, in the nuclear plants. The article considers a situation with a plane crash, the building structure load parameters generated at the impact caused by a plane impact and the following deflagration explosion of fuel vapors are determined.

scholarly journals COMPARATIVE GEOMETRICAL INVESTIGATIONS OF HAND-HELD SCANNING SYSTEMS

2016 ◽  
Vol XLI-B5 ◽  
pp. 507-514 ◽  
Author(s):  
T. P. Kersten ◽  
H.-J. Przybilla ◽  
M. Lindstaedt ◽  
F. Tschirschwitz ◽  
M. Misgaiski-Hass
Keyword(s):  
Applied Sciences ◽  
Laser Scanning ◽  
Reference Data ◽  
Test Results ◽  
University Of Applied Sciences ◽  
Humboldt University ◽  
Comprehensive Test ◽  
Structure Sensor ◽  
Scanning Systems ◽  
Test Scenarios

An increasing number of hand-held scanning systems by different manufacturers are becoming available on the market. However, their geometrical performance is little-known to many users. Therefore the Laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has carried out geometrical accuracy tests with the following systems in co-operation with the Bochum University of Applied Sciences (Laboratory for Photogrammetry) as well as the Humboldt University in Berlin (Institute for Computer Science): DOTProduct DPI-7, Artec Spider, Mantis Vision F5 SR, Kinect v1 + v2, Structure Sensor and Google’s Project Tango. In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data were acquired by measurement with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M). The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

scholarly journals Ground reference data for sugarcane biomass estimation in São Paulo state, Brazil

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Ramses A. Molijn ◽  
Lorenzo Iannini ◽  
Jansle Vieira Rocha ◽  
Ramon F. Hanssen
Keyword(s):  
Reference Data ◽  
Growth Dynamics ◽  
Sao Paulo ◽  
Biomass Estimation ◽  
São Paulo ◽  
Satellite Measurements ◽  
Paulo State ◽  
São Paulo State ◽  
Non Destructive ◽  
Production Dynamics

Abstract In order to make effective decisions on sustainable development, it is essential for sugarcane-producing countries to take into account sugarcane acreage and sugarcane production dynamics. The availability of sugarcane biophysical data along the growth season is key to an effective mapping of such dynamics, especially to tune agronomic models and to cross-validate indirect satellite measurements. Here, we introduce a dataset comprising 3,500 sugarcane observations collected from October 2014 until October 2015 at four fields in the São Paulo state (Brazil). The campaign included both non-destructive measurements of plant biometrics and destructive biomass weighing procedures. The acquisition plan was designed to maximize cost-effectiveness and minimize field-invasiveness, hence the non-destructive measurements outnumber the destructive ones. To compensate for such imbalance, a method to convert the measured biometrics into biomass estimates, based on the empirical adjustment of allometric models, is proposed. In addition, the paper addresses the precisions associated to the ground measurements and derived metrics. The presented growth dynamics and associated precisions can be adopted when designing new sugarcane measurement campaigns.

scholarly journals Digital processing of leaf area of soybeans, subjected to different treatments of seeds

2020 ◽  
Vol 13 (3) ◽  
pp. 24
Author(s):  
M. L. V. Passos ◽  
J. B. C. Souza ◽  
E. A. Silva ◽  
C. A. A. C. Silva ◽  
W. S. Sousa ◽  
...  
Keyword(s):  
Image Processing ◽  
Computer Program ◽  
Leaf Area ◽  
Seed Treatment ◽  
Digital Camera ◽  
Digital Processing ◽  
Thiophanate Methyl ◽  
Beneficial Effects ◽  
Non Destructive

Digital image processing, when applied to the study of leaf area, allows the integration of the direct measurement and non-destructive, and thus preserves the integrity of the plant. The objective was the quantification of the leaf area of soybean, cv. FTS Paragominas RR, submitted to different treatments of seed with the use of the computer program ImageJ, and basic presuppositions of image processing. The experiment was conducted at the Center of Agrarian Sciences and Environmental, Federal University of Maranhão, in Chapadinha (MA), in the period from February to June 2018. The seeds of soybean 'Paragominas RR' were submitted to the technique of seed treatment, consisting of three fungicides of the active ingredients, thiophanate methyl + fluazinam, fludioxonil and carbendazim + tiram, an insecticide active ingredient fipronil and the control. The leaf area was analyzed in the growth phase, through the use of digital camera and ImageJ®. The use of the routines in the computer program ImageJ® were effective for the determination of leaf area of the soybean submitted to different treatments of the seed. The thiophanate methyl + fluazinam in the dose 200 mL per 100 kg of seeds showed beneficial effects on growth of the cv. FTS Paragominas RR, as estimated by the leaf area.

scholarly journals Terrestrial Laser Scanning and Settled Techniques: A Support to Detect Pathologies and Safety Conditions of Timber Structures

2013 ◽  
Vol 778 ◽  
pp. 350-357 ◽  
Author(s):  
Clara Bertolini-Cestari ◽  
Filiberto Chiabrando ◽  
Stefano Invernizzi ◽  
Tanja Marzi ◽  
Antonia Spanò
Keyword(s):  
Laser Scanning ◽  
Planning Process ◽  
Laser Scanner ◽  
Texture Mapping ◽  
Surface Model ◽  
Resolution Model ◽  
Close Range ◽  
High Resolution Model ◽  
Increasing Demand ◽  
Non Destructive

Nowadays, there is an increasing demand for detailed geometrical representation of the existing cultural heritage, in particular to improve the comprehension of interactions between different phenomena and to allow a better decisional and planning process. The LiDAR technology (Light Detection and Ranging) can be adopted in different fields, ranging from aerial applications to mobile and terrestrial mapping systems. One of the main target of this study is to propose an integration of innovative and settled inquiring techniques, ranging from the reading of the technological system, to non-destructive tools for diagnosis and 3D metric modeling of buildings heritage. Many inquiring techniques, including Terrestrial Laser Scanner (TLS) method, have been exploited to study the main room of the Valentino Castle in Torino. The so-called “Salone delle Feste”, conceived in the XVIIth century under the guidance of Carlo di Castellamonte, has been selected as a test area. The beautiful frescos and stuccoes of the domical vault are sustained by a typical Delorme carpentry, whose span is among the largest of their kind. The dome suffered from degradation during the years, and a series of interventions were put into place. A survey has revealed that the suspender cables above the vault in the region close to the abutments have lost their tension. This may indicate an increase of the vault deformation; therefore a structural assessment of the dome is mandatory. The high detailed metric survey, carried out with integrated laser scanning and digital close range photogrammetry, reinforced the structural hypothesis of damages and revealed the deformation effects. In addition, the correlation between the survey-model of the intrados and of the extrados allowed a non-destructive and extensive determination of the dome thickness. The photogram-metrical survey of frescos, with the re-projection of images on vault surface model (texture mapping), is purposed to exactly localize formers restoration and their signs on frescos continuity. The present paper illustrates the generation of the 3D high-resolution model and its relations with the results of the structural survey; both of them support the Finite Element numerical simulation of the dome.

scholarly journals Weighing trees with lasers: advances, challenges and opportunities

2018 ◽  
Vol 8 (2) ◽  
pp. 20170048 ◽  
Author(s):  
M. I. Disney ◽  
M. Boni Vicari ◽  
A. Burt ◽  
K. Calders ◽  
S. L. Lewis ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Models ◽  
Tree Form ◽  
Form And Function ◽  
Challenges And Opportunities ◽  
And Function ◽  
Non Destructive

Terrestrial laser scanning (TLS) is providing exciting new ways to quantify tree and forest structure, particularly above-ground biomass (AGB). We show how TLS can address some of the key uncertainties and limitations of current approaches to estimating AGB based on empirical allometric scaling equations (ASEs) that underpin all large-scale estimates of AGB. TLS provides extremely detailed non-destructive measurements of tree form independent of tree size and shape. We show examples of three-dimensional (3D) TLS measurements from various tropical and temperate forests and describe how the resulting TLS point clouds can be used to produce quantitative 3D models of branch and trunk size, shape and distribution. These models can drastically improve estimates of AGB, provide new, improved large-scale ASEs, and deliver insights into a range of fundamental tree properties related to structure. Large quantities of detailed measurements of individual 3D tree structure also have the potential to open new and exciting avenues of research in areas where difficulties of measurement have until now prevented statistical approaches to detecting and understanding underlying patterns of scaling, form and function. We discuss these opportunities and some of the challenges that remain to be overcome to enable wider adoption of TLS methods.

Sign in / Sign up

Export Citation Format

Share Document