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The title of this thesis is 'Workflow from point cloud to BIM'. Thus, an attempt is made to present and analyse all the steps followed in such a process. The building used as a case study is U-Building which is located at KTH campus. Briefly, a report is made on the various methods of mapping existing buildings. Also, the principles of operation of 3D laser scanners are presented as well as an analysis of BIM technology. Furthermore, it is analysed the process of creating a 3D representation of the building in the form of a point cloud as well as the process of creating the 3D model with the help of two software packages. / Titeln på denna uppsats är 'Arbetsflöde från punktmoln till BIM'. Således görs ett försök att presentera och analysera alla steg som följs i en sådan process. Byggnaden som används som fallstudie är U-Building som ligger på KTH campus. Kortfattat görs en redovisning av de olika metoderna för att kartlägga befintlig bebyggelse. Dessutom presenteras principerna för driften av 3D-laserskannrar samt en analys av BIM-teknik. Vidare analyseras processen att skapa en 3D-representation av byggnaden i form av ett punktmoln samt processen att skapa 3D-modellen med hjälp av två mjukvarupaket.

A commercially available, tripod mounted, ground-based laser scanner was used to assess forest canopies and measure individual tree parameters. The instrument is comparable to scanning airborne light detection and ranging (lidar) technology but gathers data at higher resolution over a more limited scale. The raw data consist of a series of range measurements to visible surfaces taken at known angles relative to the scanner. Data were translated into three dimensional (3D) point clouds with points corresponding to surfaces visible from the scanner vantage point. A 20 m x 40 m permanent plot located in upland deciduous forest at Coweeta, NC was assessed with 41 and 45 scans gathered during periods of leaf-on and leaf-off, respectively. Data management and summary needs were addressed, focusing on the development of registration methods to align point clouds collected from multiple vantage points and minimize the volume of the plot canopy occluded from the scanner's view. Automated algorithms were developed to extract points representing tree bole surfaces, bole centers and ground surfaces. The extracted points served as the control surfaces necessary for registration. Occlusion was minimized by combining aligned point clouds captured from multiple vantage points with 0.1% and 0.34% of the volume scanned being occluded from view under leaf-off and leaf-on conditions, respectively. The point cloud data were summarized to estimate individual tree parameters including diameter at breast height (dbh), upper stem diameters, branch heights and XY positions of trees on the plot. Estimated tree positions were, on average, within 0.4 m of tree positions measured independently on the plot. Canopy height models, digital terrain models and 3D maps of the density of canopy surfaces were created using aligned point cloud data. Finally spatially explicit models of the horizontal and vertical distribution of plant area index (PAI) and leaf area index (LAI) were generated as examples of useful data summaries that cannot be practically collected using existing methods. / Ph. D.

For the first time, a novel processing method of co-refining wood and polyolefin (PO) by steam-explosion was scientifically explored for wood-thermoplastic composites without a coupling agent. Traditional studies have addressed the improvement of adhesion between components of wood thermoplastic composites through the use of coupling agents such as maleated PO. The objective of this study was to increase adhesion between wood and PO through reactive processing conditions of steam-explosion. PO characteristics, such as type (polyethylene or polypropylene), form (pellet, fiber, or powder) and melt viscosity were studied along with oxygen gas content of the steam-explosion reactor vessel. Modification of co-processed wood fiber was characterized in four studies: microscopy analysis of dispersion of PO with wood fiber, sorption properties of co-processed material, chemical analysis of fractionated components, and morphological investigation of co-processed material. Two additional studies are listed in the appendices that relate to adsorption of amphiphilic polymers to the cellulose fiber surface, which is one hypothesis of fiber surface modification by co-steam-explosion. Microscopy studies revealed that PO melt viscosity was found to influence the degree of dispersion and uniformity of the steam-exploded material. The hygroscopic nature of the co-processed fiber declined as shown by sorption isotherm data. Furthermore, a water vapor kinetics study found that all co-refined material had increased initial diffusion coefficients compared to the control fiber. Chemical changes in fractionated components were PO-type dependent. Lignin extracted from co-processed wood and polyethylene showed PO enrichment determined from an increase of methylene stretching in the Fourier Transform infrared subtraction spectra, while lignin from co-processed wood and polypropylene did not. Additionally, extracted PO showed indirect signs of oxidation as reflected by fluorescence studies. Solid state nuclear magnetic resonance spectroscopy revealed a number of differences in the co-processed materials such as increased cellulose crystallinity, new covalent linkages and an alternative distribution of components on the nanoscale reflected in the T1Ï relaxation parameter. Steam-explosion was shown to modify wood fiber through the addition of "non-reactive" polyolefins without the need for coupling agents. In light of these findings, co-refining by steam-explosion should be viewed as a new reactive processing method for wood thermoplastic composites. / Ph. D.

Digital models are essential to quantifying the behavior of structural systems. In many cases, the creation of these models involves manual measurements taken in the field, followed by a manual creation of this model using these measurements. Both of these steps are time consuming and prohibitively expensive, leading to a lack of utilization of accurate models. We propose a framework built on the processing of 3D laser scanning data to partially automate the creation of these models. We focus on steel structures, as they represent a gap in current research into this field. Previous research has focused on segmentation of the point cloud data in order to extract relevant geometries. These approaches cannot easily be extended to steel structures, so we propose a novel method of processing this data with the goal of creating a full finite element model from the information extracted. Our approach sidesteps the need for segmentation by directly extracting the centerlines of structural elements. We begin by taking "slices" of the point cloud in the three principal directions. Each of these slices is flattened into an image, which allows us to take advantage of powerful image processing techniques. Within these images we use 2d convolution as a template match to isolate structural cross sections. This gives us the centroids of cross sections in the image space, which we can map back to the point cloud space as points along the centerline of the element. By fitting lines in 3d space to these points, we can determine the equations for the centerline of each element. This information could be easily passed into a finite element modeling software where the cross sections are manually defined for each line element. / Modern buildings require a digital counterpart to the physical structure for accurate analysis. Historically, these digital counterparts would be created by hand using the measurements that the building was intended to be built to. Often this is not accurate enough and the as-built system must be measured on site to capture deviations from the original plans. In these cases, a large amount of time must be invested to send personnel out into the field and take large amounts of measurements of the structure. Additionally, these "hand measurements" are prone to user error. We propose a novel method of gathering these field measurements quickly and accurately by using a technique called "laser scanning". These laser scans essentially take a 3D snapshot of the site, which contains all the geometric information of visible elements. While it is difficult to locate items such as steel beams in the 3D data, the cross sections of these structural elements are easily defined in 2D. Our method involves taking 2D slices of this 3D scan which allows us to locate the cross sections of the structural members by searching for template cross-sectional shapes. Once the cross sections have been isolated, their centers can be mapped back from the 2D slice to the 3D space as points along the centerlines of the structural elements. These centerlines represent one of the most time consuming requirements to building digital models of modern buildings, so this method could drastically reduce the total modeling time required by automating this particular step.

Stream morphology is an important aspect of many hydrological and ecological applications such as stream restoration design (SRD) and estimating sediment loads for total maximum daily load (TMDL) development. Surveying of stream morphology traditionally involves point measurement tools, such as total stations, or remote sensing technologies, such as aerial laser scanning (ALS), which have limitations in spatial resolution. Terrestrial laser scanning (TLS) can potentially offer improvements over other surveying methods by providing greater resolution and accuracy. The first two objectives were to quantify the measurement and interpolation errors from total station surveying using TLS as a reference dataset for two fluvial applications: 1) measuring streambank retreat (SBR) for sediment load calculations; and 2) measuring topography for habitat complexity quantification. The third objective was to apply knowledge uncertainties and stochastic variability to the application of SRD. A streambank on Stroubles Creek in Blacksburg, VA was surveyed six times over two years to measure SBR. Both total station surveying and erosion pins overestimated total volumetric retreat compared to TLS by 32% and 17%, respectively. The error in SBR using traditional methods would be significant when extrapolating to reach-scale estimates of sediment load. TLS allowed for collecting topographic data over the entire streambank surface and provides small-scale measurements on the spatial variability of SBR. The topography of a reach on the Staunton River in Shenandoah National Park, VA was measured to quantify habitat complexity. Total station surveying underestimated the volume of in-stream rocks by 55% compared to TLS. An algorithm was developed for delineating in-stream rocks from the TLS dataset. Complexity metrics, such as percent in-stream rock cover and cross-sectional heterogeneity, were derived and compared between both methods. TLS quantified habitat complexity in an automated, unbiased manner at a high spatial resolution. Finally, a two-phase uncertainty analysis was performed with Monte Carlo Simulation (MCS) on a two-stage channel SRD for Stroubles Creek. Both knowledge errors (Manning's <i>n</i> and Shield's number) and natural stochasticity (bankfull discharge and grain size) were incorporated into the analysis. The uncertainty design solutions for possible channel dimensions varied over a range of one to four times the magnitude of the deterministic solution. The uncertainty inherent in SRD should be quantified and used to provide a range of design options and to quantify the level of risk in selected design outcomes. / Ph. D.

No / Brochs are monumental Iron Age (c.400–200 BC) drystone towers or roundhouses. They are only found in Scotland, particularly the Atlantic north and west. Whilst the structural layout of brochs has long been debated, few measured surveys have been conducted. Three significant broch sites form the tentative World Heritage site of “Mousa, Old Scatness and Jarlshof: the Zenith of Iron Age Shetland” (UNESCO in Mousa, Old Scatness and Jarlshof: the zenith of Iron Age Shetland, UNESCO (2019) Mousa, Old Scatness and Jarlshof: the zenith of Iron Age Shetland. http://whc.unesco.org/en/tentativelists/5677. Accessed 9 Aug 2019). All three sites have undergone new surveys as part of a collaborative doctoral partnership research project. This chapter presents a diachronic perspective using digital documentation techniques to detect stone displacement and weathering at the site of Old Scatness using historic imagery, including photographs from the Old Scatness excavations (1995–2006) and regular condition monitoring undertaken by Shetland Amenity Trust to undertake retrospective digital structure-from-motion (SfM) photogrammetry. Whilst point clouds and 3D meshes were successfully generated from low-resolution digital images, analogue film transparencies without metadata could not produce accurate geospatial data without manually trying to extant reference data. It was possible to detect displacements in stonework over time by comparing two meshes together and measuring the distances between vertex point pairs. The reliability and accuracy of these results were dependent on how well pairs of meshes could be aligned.

According to the Mine Health and Safety Administration (MSHA), between 2006 and 2016, the underground stone mining industry had the highest fatality rate in 4 out of 10 years, compared to any other type of mining in the United States. Additionally, the National Institute for Occupational Safety and Health (NIOSH) stated that structurally controlled instability is a predominant failure mechanism in underground limestone mines. This type of instability occurs when the different discontinuity sets intercept with each other forming rock blocks that displace inwards the tunnel as the excavation takes place, posing a great hazard for miners and overall mine planning. In recent years, Terrestrial laser scanning (TLS) has been used for mapping and characterizing fractures present in a rock mass. TLS is a technology that allows to generate a three-dimensional multimillion point cloud of a scanned area. In addition to this, the advances in computing power throughout the past years, have allowed numerical modeling codes to represent more realistically the behavior of a fractured rock masses. This work presents and implements a methodology that integrates laser scanning technology along with Discrete Element Modeling as tools for characterizing, preventing, and managing structurally controlled instability that may affect large-opening underground mines. The stability of an underground limestone mine that extracts a dipping ore body with a room and pillar (and eventual stoping) mining method is analyzed with this approach. While this methodology is proposed based on a specific case study that does not meet the requirements to be designed with current NIOSH published guidelines, this process proposes a general methodology that can be applied in any mine experiencing similar failure mechanisms, considering site-specific conditions. The aim of this study is to ensure the safety of mine workers and to reduce accidents that arise from ground control issues. The results obtained from this methodology allowed us to generate Probability Density Functions to estimate the probability of rock fall in the excavations. These models were also validated by comparing the numerical model results with those obtained from the laser scans. / M.S. / According to the Mine Health and Safety Administration (MSHA), between 2006 and 2016, the underground stone mining industry had the highest fatality rate in 4 out of 10 years, compared to any other type of mining in the United States. Additionally, the National Institute for Occupational Safety and Health (NIOSH) stated that structurally controlled instability is one of the main causes of rock falls in underground limestone mines. This type of instability occurs when the fractures present in the rock mass intercept each other forming rock blocks that displace into the tunnel as the excavation takes place and poses a great hazard for miners. In recent years, Terrestrial laser scanning (TLS) has been used for mapping and characterizing fractures present in a rock mass. TLS is a technology that allows to generate a three-dimensional multimillion point cloud of a scanned area. In addition to this, the advances in computing power throughout the past years, have allowed simulation softwares such as the Discrete Element Model (DEM) to represent more realistically the behavior of a fractured rock mass under excavation. The aim of this work was to develop and evaluate a methodology that could complement already exisiting design guidelines that may not apply to all kind of underground mines. The presented methodology evaluates rock failure due to presence of discontinuites, through the integration of TLS with DEM and considers site specific conditions. An area of a case study mine was assessed with this methodology, where several laser scans were performed. Information extracted from this laser scans was used to simulate the response of the rock mass under excavation by running Discrete Element Numerical Models. Results from these models allowed us to estimate the probability of rock failure in the analized areas. These, rock block failure probability estimations provide engineers a tool for characterizing, preventing, and managing structurally controlled instability, and ultimately improving workers safety.

Yes / Confocal microscopy has been increasingly employed in the field of traceology to acquire metrological data of surface changes on a micro-scale. However, its advantages for a traditional visual inspection of use-wear are rarely highlighted. As traditional optical microscopy (OM) has proven unable to entirely fulfil the prerequisites for an ideal observation of highly reflective and irregular materials, alternative ways for providing better observation conditions must be sought. In this contribution, we explore the combination of laser scanning confocal (LSCM) and scanning electron microscopy (SEM) micro-graphs for the visual characterisation of wear on quartzite and evaluate the potential of both techniques. / AHRC Fragmented Heritage project (AH/L00688X/1) at the University of Bradford, and of the MICINN-FEDER (PGC2018-093925-B-C32), the AGAUR (SGR 2017-1040) and the URV (2018PFR-URV-B2-91) projects at IPHES-URV. One of the authors (A.P.) was beneficiary of a Catalan pre-doctoral grant (2014FI B 00539), at the Rovira i Virgili University (URV), the IPHES and the Muséum national d’Histoire naturelle of Paris.

No / Excavations in the 1920s and 1970s at the Sculptor’s Cave, North-East Scotland, revealed that the site was used for mortuary rituals during the Late Bronze Age (c. 1100–800 BC) and Roman Iron Age (late first to fourth centuries AD), whilst a series of Pictish symbols carved into its entrance walls suggest that the cave’s importance continued into the Early Medieval Period. A new programme of analysis has utilised advanced 3D digital documentation and 3D metrology (specifically, 3D laser scanning) to enable this inaccessible site to be appreciated by wider audiences and analysed remotely. Detailed in situ recording of the Pictish symbols was undertaken using macro-level structured light scanning and the high-fidelity digital models blended with terrestrial laser scan data of the cave interior to show the location and detail of the carvings. This chapter examines the value of emerging digital approaches in the analysis, presentation and management of the Sculptor’s Cave, from the elucidation of additional carved details and the monitoring of surface degradation, to the dissemination of this difficult-to-access site to the wider public via online platforms. / Historic Environment Scotland provided funding for scanning work. Collaborators Visualising Heritage and Fragmented Heritage at the University of Bradford, funded by HEIF (via the University of Bradford) and the Arts and Humanities Research Council (AH/L00688X/1), respectively.