As-built documentation is an essential set of records, consisting of construction drawings, specifications and equipment location, which are kept for facility management purposes. These documents are constantly being created and modified throughout the life of a project. This process is usually manual and fraught with errors, which inhibits reliable decision making. Technological advancements have made it possible to generate 3D models to assess as-built conditions for construction monitoring purposes, such as verifying conformance to baseline project schedules and contract specifications. For this purpose, 3D point clouds are widely generated using laser scanners. However, this approach has limitations in the construction industry due to the expensive and fragile equipment, lack of portability and need of trained operators. This study aims at investigating an alternate technology to generate as-built 3D point clouds using photos taken using handheld digital cameras, compare them against the original as-built 3D models, and check for accuracy of the modeling process. This analysis can aid in more reliable and effective decision making due to its cost effectiveness and ease of use, particularly in heavy infrastructure projects which are continually undergoing rehabilitation work. To achieve these objectives, a set of guidelines are developed for taking photographs that enable effective generation of 3D point clouds using off-the-shelf software packages. The accuracy of the modeling process is investigated using the results of the as-built 3D point cloud modeling of a 2000 feet under construction bridge in southern United States. Finally, the range of tolerance and deviation of element dimensions is determined by comparing the photo based model to the actual as-built model (developed using 2D drawings). Furthermore, to compare point clouds of laser scanning and photogrammetry, a laser scan and an image based survey of an exterior wall of a university building was also done. Results show that this technology in its present state is not suitable for modeling infrastructure projects, however technological developments can enable this to be an efficient way to extract measurements of inaccessible objects for progress monitoring purposes and the models can also be stored for future dimension takeoffs for decision making and asset management purposes. / text

As-built schedules prepared during and after construction are valuable tools for State Highway Agencies (SHAs) to monitor construction progress, evaluate contractor's schedule performance, and defend against any potential disputes. However, previous studies indicate that current as-built schedule development methods are manual and rely on information scattered in various field diaries and meeting minutes. SHAs have started to collect field activity data in digital databases that can be used to automatically generate as-built schedules if proper computational algorithms are developed. This study develops computational algorithms and a prototype system to automatically generate and visualize project level and activity level as-built schedules during and after construction. The algorithm is validated using a real highway project data. The study is expected to significantly aid SHAs in making better use of field data, facilitate as-built schedule development, monitor construction progress with higher granularity, and utilize as-built schedule for productivity analysis.

Made available in DSpace on 2016-06-02T20:09:23Z (GMT). No. of bitstreams: 1 DissCGA.pdf: 3611466 bytes, checksum: eeb11ec4091908635b7db4c0128fa285 (MD5) Previous issue date: 2005-03-23 / Analyzing the existent norms, this investigation pretends to offer subsidies to collect and elaborate the information that must be include into the building user guide. In this manner, the user could accomplish correctly his functions. The focus of the research refrains from the user guide, whose objective is to transmit to the landed property s owner, in the instant of the key s delivery, the basics notions to the corrected use and maintenance of his propriety, assuring the durability, preventing damages from a bad use or the lack of conservation, and giving him a higher security and economy. For this valuation, the country s rules and legislation was analyzed, because now it claims the adoption of the manual, and norms and social behavior from other countries too, resulting in a consumer s defense movement. The work talks about constructive projects and processes used in the building sub sector and how the application of concepts and softwares can improve the satisfaction and the client s attending. The research presents too technical features like the retro alimentation and the as built project. The case study realized into this job, which consists in an interview accomplished with 11 engineers and 150 guide s users, reveals that, in spite of the consensus about the uses of the user guide, it further doesn t offers satisfactory and suitable information for it purposes. Rely on this data, the present work analyzes, comments and suggests modifications to the existents norms of the guide s elaboration serving. / Avaliando as diretrizes para formulação do manual de usuário de edificações existentes, esta investigação visa oferecer subsídios para a coleta e elaboração das informações que devem dele constar, para que cumpra, efetivamente, com o seu papel de orientar quanto ao uso e manutenção do imóvel. O foco desta pesquisa limita-se ao manual do usuário, cujo objetivo é o de transmitir, ao proprietário, as noções básicas para a correta utilização e manutenção da sua propriedade, assegurando a durabilidade, evitando e prevenindo danos decorrentes do mau uso ou falta de conservação, aumentando a segurança e a economia. Para tal avaliação, no decorrer desta dissertação foram analisadas as normas e a legislação vigente no País, que passaram a exigir a adoção do manual, bem como normas e comportamentos sociais de outros países, resultantes do movimento de defesa dos consumidores. O trabalho discorre sobre projetos e processos construtivos utilizados no subsetor da construção civil, bem como sobre a aplicação de conceitos e programas de qualidade e dos benefícios que podem ser deles extraídos para o melhor desempenho do produto no atendimento e satisfação do cliente. Apresenta ainda aspectos técnicos tais como retroalimentação e projeto as built . O estudo de caso realizado neste trabalho, que conta com uma análise de 11 manuais fornecidos por construtoras, bem como uma pesquisa realizada com 11 engenheiros que respondem por construtoras e 150 usuários de manual, revela que, apesar do consenso da importância do manual, este ainda não traz informações adequadas e satisfatórias para a sua finalidade, não atendendo plenamente aos requisitos necessários. Com base nestes dados, o presente trabalho analisa, comenta e fornece contribuições para as diretrizes existentes voltadas para a elaboração do manual.

Existing residential and small commercial buildings now represent the greatest opportunity to improve building energy efficiency. Building energy simulation analysis is becoming increasingly important because the analysis results can assist the decision makers to make decisions on improving building energy efficiency and reducing environmental impacts. However, manually measuring as-is conditions of building envelops including geometry and thermal value is still a labor-intensive, costly, and slow process. Thus, the primary objective of this research was to automatically collect and extract the as-is geometry and thermal data of the building envelope components and create a gbXML-based building geometry model. In the proposed methodology, a rapid and low-cost data collection hardware system was designed by integrating 3D laser scanners and an infrared (IR) camera. Secondly, several algorithms were created to automatically recognize various components of building envelope as objects from collected raw data. The extracted 3D semantic geometric model was then automatically saved as an industry standard file format for data interoperability. The feasibility of the proposed method was validated through three case studies. The contributions of this research include 1) a customized low-cost hybrid data collection system development to fuse various data into a thermal point cloud; 2) an automatic method of extracting building envelope components and its geometry data to generate gbXML-based building geometry model. The broader impacts of this research are that it could offer a new way to collect as is building data without impeding occupants’ daily life, and provide an easier way for laypeople to understand the energy performance of their buildings via 3D thermal point cloud visualization.

The documentation of complete and timely as-built information related to construction projects is essential for tracking progress, planning corrective action, and analyzing the schedule. The collection of site information, however, is currently a challenging, time-consuming, and error-prone manual process. To improve the tracking of as-built information, this research focused on the development of a low-cost voice-visual framework that utilizes commonly available communication tools such as email and interactive voice response (IVR). The goal of this research was to create project-wide bidirectional communication between site personnel and head office to automate the tracking of daily site information. The research involved an in-depth analysis of the possible site events and progress-tracking needs related to construction activities. Accordingly, activity-specific email forms and logical-flow diagrams were developed as a means of facilitating site data collection. A framework was then developed that integrates several components: the developed tracking forms; a cloud-based IVR service; a customized scheduling application; and an email application. During construction, the automated system identifies eligible activities to be tracked; collects as-built details from the relevant supervisors; and uses the daily time segments of the schedule as an integrated depository for all as-built details, including progress information, events by all parties, and requests for information (RFIs), quality/safety issues, and other video/audio/drawing-markup notes. The developed system generates detailed as-built schedule that clearly show the evolution of all as-built events and their accurate timing on the daily segments for each activity. The project schedule is thus converted from a static report into information-rich, visualization media, and decision-support tool that provides decision makers with timely progress details so that they can easily follow the project progress , facilitates schedule updates, facilitates accurate schedule forensics, delay analysis, , and the planning of appropriate corrective action. The developed framework was validated though a number of case studies that demonstrated its usefulness and practicality. This research contributes to construction efficiency through the facilitation of bidirectional communication between site personnel and head office and the provision of timely and legible as-built data for decision-making. Ultimately, the research will assist construction firms to have better control over construction projects and more effective decisions during construction through improved communication.

The documentation of complete and timely as-built information related to construction projects is essential for tracking progress, planning corrective action, and analyzing the schedule. The collection of site information, however, is currently a challenging, time-consuming, and error-prone manual process. To improve the tracking of as-built information, this research focused on the development of a low-cost voice-visual framework that utilizes commonly available communication tools such as email and interactive voice response (IVR). The goal of this research was to create project-wide bidirectional communication between site personnel and head office to automate the tracking of daily site information. The research involved an in-depth analysis of the possible site events and progress-tracking needs related to construction activities. Accordingly, activity-specific email forms and logical-flow diagrams were developed as a means of facilitating site data collection. A framework was then developed that integrates several components: the developed tracking forms; a cloud-based IVR service; a customized scheduling application; and an email application. During construction, the automated system identifies eligible activities to be tracked; collects as-built details from the relevant supervisors; and uses the daily time segments of the schedule as an integrated depository for all as-built details, including progress information, events by all parties, and requests for information (RFIs), quality/safety issues, and other video/audio/drawing-markup notes. The developed system generates detailed as-built schedule that clearly show the evolution of all as-built events and their accurate timing on the daily segments for each activity. The project schedule is thus converted from a static report into information-rich, visualization media, and decision-support tool that provides decision makers with timely progress details so that they can easily follow the project progress , facilitates schedule updates, facilitates accurate schedule forensics, delay analysis, , and the planning of appropriate corrective action. The developed framework was validated though a number of case studies that demonstrated its usefulness and practicality. This research contributes to construction efficiency through the facilitation of bidirectional communication between site personnel and head office and the provision of timely and legible as-built data for decision-making. Ultimately, the research will assist construction firms to have better control over construction projects and more effective decisions during construction through improved communication.

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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.

The forecast of the next upcoming years estimates a growth of demand in transport. As the railway sector in Europe has developed over many years, the infrastructure presents performance issues because of, among other factors, asset maintenance activities being difficult and time consuming. There are currently 4000 railway bridges in Sweden managed by Trafikverket which are submitted to inspections at least every six years. The most common survey is done visually to determine the physical and functional condition of the bridges as well as finding damages that may exist on them. Because visual inspection is a subjective evaluation technique, the results of these bridge inspections may vary from inspector to inspector. The data collection is time consuming and written in standard inspection reports which may not provide sufficient visualization of damages. The inspector also needs to move around the bridge at close distance which could lead to unsafe working conditions. 3D modelling technology is becoming more and more common. Methods such as Close Ranged Photogrammetry (CRP) and Terrestrial Laser Scanning (TLS) are starting to be used for architecture and heritage preservation as well as engineering applications. Infrared (IR) scanning is also showing potential in creating 3D models but has yet not been used for structural analysis and inspections. A result from these methods is a point cloud, a 3D representation of a model in points that can be used for creating as-built Building Information Modeling (BIM)-models. In this study, the authors put these three methods to test to see if IR scanning and CRP are suitable ways, such as TLS is, to gather data for 3D-reconstruction of concrete railway bridges in fast, safe and non-disturbing ways. For this, the three technologies are performed on six bridges chosen by Trafikverket. The further aim is to determine if the 3D-reconstructions can be used for acquiring BIM-information to, among other things, create as-built drawings and to perform structural evaluations. As a result from the study, IR scanning and CRP show great potential as well as TLS in 3D-reconstruction of concrete railway bridges in fast, safe and non-disturbing ways. Still, there is a need of development regarding the technologies before we can start to rely on them completely.

Aufgrund rechnerischer Defizite werden aktuell in Deutschland zahlreiche Brückenbauwerke durch Neubauten ersetzt. Bevor der Neubau errichtet werden kann, muss das bestehende Brückenbauwerk rückgebaut werden. Häufig liegen im Zuge der Rückbauplanung jedoch keine aktuellen Bestands- und Zustandsinformationen vor, die Planung erfolgt entsprechend anhand von Bestandsplänen und Annahmen zum tatsächlichen Bauwerkszustand. Eine deutlich realitätsnähere, und damit im Allgemeinen sichere, Bewertung ist mithilfe von Bestandsuntersuchungen möglich. Im Rahmen eines Forschungsprojektes sollen am Beispiel einer typischen Spannbetonbrücke der 1960er Jahre umfangreiche Bestandsuntersuchungen durchgeführt, wissenschaftlich ausgewertet und im Hinblick auf die Optimierung von Bestands- und insbesondere Rückbauplanungen bewertet werden. Dabei werden drei wesentliche Aspekte beleuchtet: die Erstellung von geeigneten Bestandsmodellen, die Ermittlung der Betoneigenschaften für die rechnerische Bewertung und die Beurteilung der nachträglichen Verankerung von Spanngliedern. Im Rahmen des Tagungsbeitrags sollen die durchgeführten Untersuchungen und vorliegenden Zwischenergebnisse präsentiert werden.