Application of 4D visualization technology for safety management in metro construction

Safety accidents occur frequently in underground metro construction due to its complexity. These accidents cause huge losses because most metro construction is located in the center of very congested cities. Therefore, safety management is a priority in the metro construction industry. This paper proposes an approach for safety management using visualization technology. Safety is integrated with the construction management process throughout the project life cycle. Information from the design phase about construction components and scheduling has been gathered to formulate a 4 dimensional (4D) model. Before construction begins, a rule-based tool analyzes this combined information, automatically detects potentially unsafe activities and conditions and provides instructions for correction. More importantly, actual site monitoring data are continuously compared to the 4D model during the construction process. Therefore, the safety status of related components can be continuously visualized in the system as conditions change and potential safety risks evolve. This paper presents a prototype which was developed and verified with a case study of a real project. The results show that the proposed approach can be a tool of collaboration, virtual analysis and prediction for designers, site project managers, safety engineers and other participants. With real-time safety status visualized, it can detect safety risks before and during the construction process and then provide preventive measures. Thus, timely decisions can be made to avoid accidents. This contributes to the success of safety management in the metro construction industry.     

IFC model viewer to support nD model application

Today, building information modelling (BIM) plays a crucial role in the research and development fields of construction information integration and interoperability. This paper, from an information technology point of view, outlines the definition and aims of the “3D to nD Modelling” project, a platform grant-funded project by UK’s British Engineering and Physics Sciences Research Council (EPSRC). It presents a scenario of widening BIM implementation into the overall aspects involved in the whole life cycle of a building project. Industry foundation classes (IFC) as a standard BIM specification has been adopted as a central information repository in order to deliver the integrated building information throughout the nD-driven assessments, evaluation and decision-making. This paper also focuses on the development of an IFC-viewer, which is defined as the holistic interface of the nD modelling tool. The techniques and methods including the auxiliary tools adopted in this development are detailed. This development presents a practical and economic way to reveal and retrieve the information of IFC models inclusively, structurally and visually.     

软土地区某基坑失稳事故分析

主要介绍了上海地区某基坑工程失稳事故。水泥搅拌桩由于施工简便,经济性好等优点,在此工程中作为围护结构使用。但是由于施工场地不合理的堆载及其他一些因素导致基坑东北角水泥搅拌桩围护结构发生破坏。本文通过有限元软件对该事故进行分析,为今后的工程提供依据。     

The Computer Integrated Road Construction project

This paper is about the “Computer Integrated Road Construction” (CIRC) project, which is a Brite-EuRam III funded project, lasting 1997–1999, aiming at introducing a new generation of control and monitoring tools for road pavements construction. These new tools are designed to bring on the sites significant improvements by creating a digital link between design office and job site. The first part of the paper describes the background of the project, which gathers seven European partners from five different countries, and gives the objectives of the project, in general and for each of the two targeted products: one for the compactors (CIRCOM) and one for the asphalt pavers (CIRPAV). Then, the two prototypes are described, each of them being broken down into three main sub-systems: the ground sub-system (GSS), the on-board sub-system (OB) and the positioning sub-system (POS). The expected benefits for the different users are also presented and quantified. The central part of the paper is devoted to the main technical innovations that have been developed in the frame of the project: universal vector database for road equipment guidance, multi-machine functionalities of CIRCOM and the two positioning systems which are actually the technological keys of the systems. Finally, the state of progress of the developments of the two CIRC products and the first commercial success achieved in parallel are presented.     

A BIM based tool for assessing embodied energy for buildings

Assessment of the energy associated with the material production,transportation and construction of buildings provides an opportunity for reducing the use of energy and improving sustainability. Building Information Modeling( BIM) provides a platform to incorporate sustainability information in the design of buildings. How ever,interoperability of BIMw ith Life Cycle Assessment( LCA) tools needs further investigation. Previous research in this area has either partially employed BIM; data wasexported from the main BIMauthoring tool and then auxiliary tools were utilized to evaluate the model,thereby causing a disconnect betw een the model and analysis resulting in non-interoperable systems,or has ignored the importance of retaining the LCA results within the BIMenvironment. To address this issue,this paper presents a framew ork to estimate the embodied energy content within the native BIMenvironment. The implementation of this framew ork is illustrated by the development of a tool for estimation of material embodied energy,transportation energy and construction energy. A prototype of the tool has been implemented on a case project to establish the workability of the framework.     

Managing construction information using RFID-based semantic contexts

Quick and correct information capturing, archival and retrieval in construction sites is essential to support project management. This paper presents a new methodology for managing construction document information using RFID-based semantic contexts. The methodology deploys four main tools for construction document archival and retrieval: (1) template document metadata modules that formulate document information; (2) semantic ontologies for indexing construction documents; (3) RFID framework for automatic identification of construction concepts; and (4) an ontological indexing mechanism to reason about ontological semantic relationships and infer applicable concepts for indexing. To demonstrate the role and contribution of the new proposed methodology, first a template for construction problem documents module has been constructed. Then, a new object-oriented Java-based prototype was developed to leverage RFIDs and OWL (Web Ontology Language)-based ontologies for reasoning about indexed construction concepts. Finally, a case study has been performed to validate the new methodology's capability of supporting users through available RFID information in the selection of construction concepts for archiving and retrieving related, stored documents from a relational corporate database of construction problems. The new methodology implementation shows a number of direct impacts such as the effectiveness of document archival and retrieval and the efficiency of fusing information. The new methodology is described in the paper, including findings obtained from the case study and a discussion of future research.     

向着“IDP-BIM”框架体系转变：“可持续性发展之屋”的实例研究

IDP和BIM已经被公认为是解决建筑行业离散化问题的两个途径。然而要实施新的方法和工具,需要在设计实践中采取重大变革。本篇表述了一个研究项目中的一部分,该项目的最终目标是开发一种新型的知识体系,即IDP-BIM框架体系。本文着重阐述了在该背景下所实施的案例研究,包括对一座高性能建筑——位于蒙特利尔的＂可持续性发展之屋（HSD）＂的设计程序进行的族群观察,并探讨了拟定的可持续性策略的针对性。该实例研究的另一个尝试是在由专业人士团队完成设计后,采用BIM技术对设计过程进行了＂逆向工程＂设计。本文展现了这部分实例研究的成果,旨在为综合建模确定一个最佳数字环境和顺畅的工作流程。为全面表达项目,我们首先建立了该建筑的BIM模型（基于Revi软件）。然后,我们为规划、施工过程的成本估算模拟、被动式太阳热能和照明模拟进行了性能和互操作性测试。本实例研究的结果涵盖了以下方面Revit软件在设计最初阶段的可用性;主BIM模型的互操作性和数据交换能力,模拟结果的一致性。我们还为可持续性发展之屋的设计者提供了一些建议。工作流程的研究结果也丰富了＂IDP-BIM＂模型框架体系。     

Hazard ontology and 4D benchmark model for facilitation of automated construction safety requirement analysis

Over the last two decades, numerous approaches have been developed for automating construction safety assessment, that is, prevention through design and planning (PtD/P), that overcome the limitations of a purely manual safety assessment process. Despite this, such automated approaches are yet to be widely adopted in practice. Barriers include a lack of standardization of construction safety concepts within regulatory frameworks and a lack of confidence in automated approaches on the part of practitioners. This work presents a freely available 4D BIM-based benchmark model (3D Building Information Model and 68 schedules) and construction safety ontology covering the two most frequent and severe construction site accidents: falls from height and struck-by falling object hazards. The benchmark model and ontology enable the construction safety community to test and compare the performance of alternative automated approaches. Moreover, they are utilized in our PtD/P tool SafeConAI, and empirical evaluation results show how the safety situation changes among different construction schedules of the same project.     

Applicability of 4D modeling for resource allocation in mega liquefied natural gas plant construction

Four-dimensional (4D) modeling has gained much potential in improving construction process design and planning. The integration of three-dimensional model with scheduling information has been shown to enable the effective detection of construction process design and planning flaws. However, the research work in 4D has been predominantly focused on the building construction industry. 4D has been rarely explored in the oil and gas industry, particularly Liquefied Natural Gas (LNG) plant construction. It is very difficult to conceive the scale and complexity of mega-projects in the LNG sector. This paper presents a study with the goal of investigating the feasibility and benefits of 4D in supporting LNG construction projects. 4D models were developed at both the activity level and the operations level, and geometry-based virtual construction was implemented to rehearse the construction process for the purpose of identifying potential risks and safety issues. These models were used for synergistic planning for the whole project and for resource scheduling. It has been demonstrated in this paper, mega LNG construction projects can benefit from 4D in terms of improved process planning and control.     

Quantitative analysis of workflow, temporary structure usage, and productivity using 4D models

This paper presents time–space analyses of construction operations supported by quantitative information extracted from 4D CAD models. The application of 4D models is a promising approach to help introduce construction innovations and to evaluate construction alternatives. Current analyses of 4D models are mainly visual and provide project stakeholders with a clear, but limited, insight of construction planning information. This practice does not take advantage of the quantitative data contained in 4D models. We use two 4D models of an industry test case to illustrate how to analyze, compare, and present 4D content quantitatively (i.e., workspace areas, work locations, and distances between concurrent activities). This paper shows how different types of 4D content can be extracted from 4D models to support 4D-content-based analyses and novel presentation of construction planning information. We suggest further research aimed at formalizing the contents in 4D models to enable comparative quantitative analyses of construction planning alternatives. Formalized 4D content can enable the development of reasoning mechanisms that automate 4D-model-based analyses and provide the data content for presentations of construction planning information.     

4D CAD model updating using image processing-based construction progress monitoring

For a four-dimensional (4D) computer-aided design (CAD) model to be useful for users throughout a construction project, the model must be updated in a timely and accurate manner during the construction. Only when it has been properly updated can the 4D CAD model reflect the real progress of a construction site to inform managerial decision making. However, updating a 4D CAD model is time-consuming and labor-intensive because the full updating process, from site data acquisition to 4D model regeneration, is typically conducted manually. This difficulty in updating a 4D model discourages industry practitioners from actively adopting 4D models. This paper presents an image processing-based methodology for the automatic updating of a 4D CAD model. Characterized by 3D CAD-based image mask filters, color-based noise removal, and area-based progress calculation, the image processing approach provides as-built schedule information. The schedule information is then automatically integrated with an existing 3D CAD model in batch-processing modes to produce the updated 4D CAD model. The proposed methodology was applied and verified in a cable-stayed bridge construction project and is expected to facilitate the wider use of 4D CAD models in the construction industry.     

Application of 4D for dynamic site layout and management of construction projects

Construction schedules and site space arrangement are essential to project management, as they directly influence security, machine running, material deployment, power distribution as well as construction progress and cost. There has been a strong need for more effective planning and management of site space and facilities. This paper introduces a 4D Integrated Site Planning System (4D-ISPS) which integrates schedules, 3D models, resources and site spaces together with 4D CAD technology to provide 4D graphical visualization capability for construction site planning. The features of 4D-ISPS are described in detail. The implementation techniques of this system are also discussed and a real life case is presented.     

Integrating 3D visualization and simulation for tower crane operations on construction sites

Most high-rise building construction projects rely on tower cranes to perform lifting and hoisting activities. In practice, tower cranes are managed based on demand, urgency, and prioritized work tasks that must be performed within a set period of time in the field. As a computer tool, simulation has proved to be effective in modeling complex construction operations and can be a substantial help in aiding practitioners in construction planning. However, the use of simulation has fallen far below its maximum potential due to a lack of appropriate support tools which would allow construction managers to use simulation tools for themselves. Special purpose simulation (SPS) and 3D visualization of simulated operations are two potential means that enable domain experts, who are knowledgeable in give domains, but not familiar with simulation, to easily model an operation within their domain and analyze the simulation results. This paper presents a practical methodology for integrating 3D visualization with SPS for tower crane operation. An integrated system was built in a 3D Studio MAX environment and tested in the construction of the new civil and environmental engineering building at the University of Alberta. This paper demonstrates that 3D visualization is helpful in the verification and validation of simulation results, and can effectively communicate the essence of a simulated operation, thus improving the accessibility of simulation as a decision making aid.     

An evaluation of the applicability of 4D CAD on construction projects

4D CAD models that integrate physical 3D elements with time, have been used to visualize construction processes in several projects worldwide. 4D models have been used and have been shown to have benefits over processes that span the entire lifecycle of a project such as collaboration with stakeholders, making design decisions, assessing project constructability, identifying spatial conflicts in construction and so on. Despite these benefits, several organizational and project-specific barriers have hindered the widespread adoption of 4D CAD. In order to reconcile the theoretical benefits of 4D models with the practical difficulties faced in implementation, there is an urgent need to explore the implementation of 4D models on construction sites as well as the perceptions of intended users/beneficiaries towards this implementation. This paper aims to address this need and contribute to our understanding of how 4D models must be introduced, positioned and implemented on construction sites, so as to maximize both their acceptability and their usefulness. We describe two 4D models of infrastructure projects and two 4D models of commercial projects that have been built and implemented. Through a process of structured and unstructured interviewing the paper gauges the response of project participants across various organizational levels on each of these projects as to the usefulness of 4D in project planning and control. Through qualitative and statistical analysis of the data we establish that 4D CAD is likely to be most beneficial in the project shaping or planning stage and in the construction stage. In the project shaping stage, 4D CAD is likely to be particularly useful in communicating construction plans and processes to clients, while during the construction phase, 4D CAD is likely to be particularly useful in comparing the constructability of work methods visually in order to detect conflicts or clashes, and as a visual tool for contractors, clients, subcontractors and vendors to review and plan project progress. Further, upper management and site workers are more likely to use and derive benefits from the visualization of processes using 4D given their lack of site related knowledge or skills, while construction professionals who are more construction-savvy are more likely to appreciate and benefit from the analytical and planning aids that 4D simulations provide during the construction phase. However, it is likely that despite these benefits 4D CAD models might not diffuse through the construction industry unless 4D modelling and analysis is integrated into existing project planning approaches. The paper concludes with a brief discussion on future 4D software development that seeks to bring about such integration and leverages the benefits of 4D CAD to bring about improved operational efficiencies on construction sites.     

Value creation using the mission breakdown structure

The modern concept of project success includes the project contributing to the value creation of its base organization. We need tools to discuss what the project itself and the base organization should do to enhance this value creation. The Mission Breakdown Structure tool helps a company set up a project with a clearly defined mission and secures an effective interplay between the base organization and its project. This article presents the tool in principle and use an illustrative real-life case. The case looks like an IT project at the outset, but when using the Mission Breakdown Structure tool, we recognise that it is much more than that and that different stakeholders need to be involved to secure a successful project. Advice on how to use the Mission Breakdown Structure tool is also provided.     

Generating, evaluating and visualizing construction schedules with CAD tools

Collaborative AEC technologies centering around component-based CAD models support architectural and structural perspectives. The construction perspective is often neglected because an important dimension for construction–time–is missing. Construction planners are forced to abstract CAD model building components into schedule models representing time. 4D-CAD (3D-CAD+time) removes this abstraction by linking a 3D building model and schedule model through associative relationships. Adding time to 3D-CAD models extends the use of CAD tools from the design phase to the construction phase. Although commercial 4D tools exist that allow planners to build 4D models and create graphic simulations of the construction process, these tools lack features to support analysis of these models, easy generation and manipulation of such models, and realistic visualizations of the construction process. This paper discusses these shortcomings, highlights requirements for CAD tools to support construction planning tasks, and describes our efforts to develop 4D tools that generate 4D+x models that more realistically represent the construction process.     

Strategic use of quality function deployment (QFD) in the construction industry

In this paper, an attempt has been made to examine the applicability of QFD as a strategic decision-making tool after the construction stage of a housing project to determine the best marketing strategy, to make a comparison between the performances of different competitors and to transfer the experience gained from the current project to the forthcoming projects. For this purpose, a QFD team has been formed to collect and verify the expectations of the customer profile of the sample project, which was a high-rise building project located in Ankara, Turkey. The case study findings demonstrated that QFD could be successfully applied in the housing projects as a strategic tool to facilitate marketing decisions. As a result of extensive literature review and the case study observations; the paper also points out the limitations and breakthroughs of the QFD methodology. Finally, critical success factors are proposed to improve the performance of the QFD methodology in construction projects.     

Decision support for construction method selection in concrete buildings: Prefabrication adoption and optimization

Prefabrication offers a substantial opportunity to improve projects' sustainable performance. However, decisions to employ prefabrication are still largely based on familiarity and personal preferences rather than rigorous data. Methodical assessments of an appropriate construction method for a concrete project have been found deficient. This paper presents an objective and transparent tool, the Construction Method Selection Model (CMSM), which is designed to aid building team members during early project stages in evaluating the feasibility of prefabrication and exploring an optimal strategy to apply prefabrication in concrete buildings. The model is divided into two sequential levels: the strategic level and the tactical level, respectively. The Simple Multi-Attribute Rating Technique (SMART) is used in the first level for preliminary feasibility evaluation of prefabrication. The Multi-Attribute Utility Theory (MAUT), which considers uncertainty and risk attitude, is employed in the second level to assess to what degree of prefabrication is appropriate for the project at hand. A detailed case study through in-depth personal interviews with four decision makers is presented to illustrate the use of the model and to demonstrate the capability of the model. The results show that the proposed model is a useful and effective decision-making tool for prefabrication adoption and optimization in concrete buildings.     

4D CAD技术在施工管理中的应用研究

4D CAD技术属于计算机技术在工程施工领域应用的一项新技术，本文作者通过论述4D CAD技术的发展，分析了4D CAD技术在施工管理中的优势。通过对比分析常见4D CAD软件的基本功能，结合一座大型桥梁工程的施工实践，具体说明4D CAD技术的优点和应用障碍。最后，提出4DCAD技术发展的趋势和方向。