36 research outputs found
A Framework for BIM-Enabled Life-Cycle Information Management of Construction Project
BIM has been widely used in project management, but on the whole the applications have been scattered and the BIM models have not been deployed throughout the whole project life-cycle. Each participant builds their own BIM, so there is a major problem in how to integrate these dynamic and fragmented data together. In order to solve this problem, this paper focuses on BIM-based life-cycle information management and builds a framework for BIM-enabled life-cycle information management. To organize the life-cycle information well, the information components and information flow during the project life-cycle are defined. Then, the application of BIM in life-cycle information management is analysed. This framework will provide a unified platform for information management and ensure data integrit
From Building Information Modeling to City Information Modeling
With the development of Geographic Information System (GIS), the concept of digital city is implemented widely. However, in practice, most of the GIS models are relatively poorly attributed, semantically. Building Information Modeling (BIM) is a process involving the generation and management of digital representations of physical and functional characteristics of building, which is most used in small scale projects. In order to address the target problem of completing the semantic attribution of 3D digital city model, a framework of integrating BIM technology into GIS is demonstrated. A new concept of city information modeling (CIM) is proposed with the goal of bringing great benefits to the urban construction and city management. The composition of city information model is discussed. The data schema behind BIM and GIS (i.e. IFC and CityGML) are compared and mapped with each other. A case study of land planning of campus is demonstrated to present the potential benefits of CIM
Integrating BIM with building performance analysis in project life-cycle
Adopting Building Information Modelling (BIM) in Building Performance Analysis (BPA) is becoming an emerging research area in the application of information technology in the Architecture, Engineering, and Construction (AEC) industry. To investigate the current state of research in the adoption of BIM in BPA, this study performed a holistic review consisting of a bibliometric analysis of existing literature, content analysis of selected studies, as well as follow-up qualitative discussion in BIM integration with BPA. The bibliometric analysis identified 60 relevant studies; the content analysis of these studies revealed the research focuses of BIM-enabled BPA, including interoperability, semantics, and sustainability rating systems; the qualitative discussion further highlighted the learning process throughout project delivery stages and addressed the potential gap between ‘as-designed’ building performance and ‘as-built’ performance. Overall, this study contributes to existing research by identifying key input attributes and workflow in BPA, reviewing the state-of-the-art research on BIM integration with BPA, and investigating the major research areas, namely, interoperability issues in BIM-enabled BPA within the context of life-cycle BPA
Bim-Based Risk Identification System in tunnel construction
This paper presents an innovative approach of integrating Building Information Modeling (BIM) and expert systems to address deficiencies in traditional safety risk identification process in tunnel construction. A BIM-based Risk Identification Expert System (B-RIES) composed of three main built-in subsystems: BIM extraction, knowledge base management, and risk identification subsystems, is proposed. The engineering parameter information related to risk factors is first extracted from BIM of a specific project where the Industry Foundation Classes (IFC) standard plays a bridge role between the BIM data and tunnel construction safety risks. An integrated knowledge base, consisting of fact base, rule base and case base, is then established to systematize the fragmented explicit and tacit knowledge. Finally, a hybrid inference approach, with case-based reasoning and rule-based reasoning combined, is developed to improve the flexibility and comprehensiveness of the system reasoning capacity. B-RIES is used to overcome low-efficiency in traditional information extraction, reduce the dependence on domain experts, and facilitate knowledge sharing and communication among dispersed clients and domain experts. The identification of a safety hazard regarding the water gushing in one metro station of China is presented in a case study. The results demonstrate the feasibility of B-RIES and its application effectiveness
Development of Key Domain-Relevant Technologies for Smart Construction in China
Smart construction integrates new-generation information technology with construction and is important for the highquality development of China’s construction industry. This study expounds the basic concept and importance of smart construction and summarizes four types of key domain-relevant technologies: engineering software for entire industrial chain integration, construction Internet of things for smart construction sites, intelligent construction machinery for man–machine integration, and construction big data for intelligent decision making. Subsequently, we analyze the current status and weaknesses of these technologies in terms of market environment, enterprise deployment, and core resource reserves through questionnaire survey and expert interview. Moreover, we identify the development goals and propose the major tasks, including establishing and improving the standards system; promoting cooperation among industry, universities, research institutes, and application; improving intellectual property protection; and conducting pilot demonstration of typical projects. Furthermore, suggestions are proposed from the perspectives of government, enterprises, and universities
Non-linear description of ground settlement over twin tunnels in soil
Tunneling inevitably leads to ground settlement. The ground settlement trough over a single tunnel is well described by the generally accepted Peck’s formula. A new model of settlement trough is proposed by extending Peck’s formula to the case of horizontally aligned twin tunnels, which is a widely used tunnel configuration in urban metro projects. The feasibility of the new model is demonstrated through exploration of a large amount of ground settlement data accumulated from a metro tunnel project in China. Two numerical methods are implemented in the data exploration process to solve the problem of non-linear curve-fitting and estimation of model parameters. The Levenberg–Marquardt method is shown to be more suitable than the Nelder–Mead method. Based on the new model of settlement trough, a new method for calculating ground loss over twin tunnels is also proposed. The concluded empirical value of the ratio of ground loss is considered to provide an excellent reference for similar urban railway projects in the future
Highway Planning and Design in the Qinghai–Tibet Plateau of China: A Cost–Safety Balance Perspective
Engineering designs for mountainous highways emphasize compliance checking to ensure safety. However, relying solely on compliance checking may lead designers to minimize costs at the expense of high risk indicators, since the overall risk level of the highway design is unknown to the designers. This paper describes a method for the simultaneous consideration of traffic safety risks and the associated cost burden related to the appropriate planning and design of a mountainous highway. The method can be carried out in four steps: First, the highway design is represented by a new parametric framework to extract the key design variables that affect not only the life-cycle cost but also the operational safety. Second, the relationship between the life-cycle cost and the operational safety risk factors is established in the cost-estimation functions. Third, a fault tree analysis (FTA) is introduced to identify the traffic risk factors from the design variables. The safety performance of the design solutions is also assessed by the generalized linear-regression model. Fourth, a theory of acceptable risk analysis is introduced to the traffic safety assessment, and a computing algorithm is proposed to solve for a cost-efficient optimal solution within the range of acceptable risk, in order to help decision-makers. This approach was applied and examined in the Sichuan–Tibet Highway engineering project, which is located in a complex area with a large elevation gradient and a wide range of mountains. The experimental results show that the proposed approach significantly improved both the safety and cost performance of the project in the study area. Keywords: Highway planning and design, Cost–safety optimization, Acceptable risk assessment, Sichuan–Tibet Highwa
Optimization strategies to eliminate interface conflicts in complex supply chains of construction projects
The supply chains of complex construction projects are characterized by multi-disciplinary participants, adversarial short-term relationships and fragmentations in project delivery procedures. Multi-disciplinary participants tend to make decisions on project activities based on their own objectives and value systems independently with little regard of holistic project performance. The lack of common values results in a limited understanding of how behaviors of one discipline impact on the related disciplines. This has led to tons of interface conflicts which ultimately affect project effectiveness. This paper investigates this problem by discussing Interface Value for the core players to understand the value-driven behaviors on the boundaries among owner and multiple prime contractors in complex construction projects. Two types of interface conflicts are recognized and defined. Value Optimization Strategy is proposed under status quo delivery methods by adjusting and reallocating interface responsibilities between related contractors. Improvements of procurement procedures are the key solutions to interface conflicts. Prospects of integrated project delivery (IPD) in eliminating interface conflicts are also discussed. The paper concludes that Value Optimization Strategy and IPD-based approach are expected to eliminate interface conflicts of complex construction projects, integrate the complex supply chain and lower the potential risks for project delivery delay and cost overrun.
First published online: 03 Apr 201
Large-scale data reveal disparate associations between leisure time physical activity patterns and mental health
Abstract Background Leisure time physical activity (LTPA) is known to be associated with a lower risk for mental health burden, while whether the underlying mechanisms vary across populations is unknown. We aimed to explore the disparate associations between LTPA and mental health based on large-scale data. Methods In this study, we analyzed data including 711,759 individuals aged 15 years or above from the latest four rounds (2003, 2008, 2013, and 2018) of the National Health Service Survey (NHSS) in China. We used multiple logistic regression models adjusted for potential confounders to investigate associations between LTPA and mental health in the total population and subgroups by measuring a diverse set of activity frequencies, intensities, and types. To examine the dose-response associations between total activity volume and mental health, we conducted restricted cubic splines to investigate possible nonlinearity. Results LTPA was associated with remarkably lower self-reported mental health burden (OR 0.56, 95% CI 0.54–0.58). The dose-response relationship between total activity volume and mental health was highly nonlinear (p < 0.001), presenting L-shaped with first 1200 metabolic equivalents of task (METs)-min/week for significant risk reduction (OR 0.58, 95% CI 0.56–0.60). Notably, merely exercising 3–5 times per week with moderate swimming was significantly associated with lower mental health burden among younger people, while the association was strongly large in older adults aged 60 years or above doing 55-min moderate apparatus exercise at least six times a week. Conclusions In a large Chinese sample, LTPA was meaningfully and disparately associated with mental health burden across different people. Policy targeted at prompting activity may be effective for reducing mental health burden, but importantly, tailored strategies are needed based on population contexts
Improved fuzzy Bayesian network-based risk analysis with interval-valued fuzzy sets and D-S evidence theory
A novel risk analysis approach is developed by merging interval-valued fuzzy sets (IVFSs), improved Dempster-Shafer (D-S) evidence theory, and fuzzy Bayesian networks (BNs), acting as a systematic decision support approach for safety insurance for the entire life cycle of a complex system under uncertainty. Aiming to alleviate the problem of insufficient and imprecise data collected from the complicated environment, the expert judgment in linguistic expressions is employed to describe the risk levels for all risk factors, which are represented by IVFSs using Gaussian membership function to fully consider such fuzziness and uncertainty. In regard to interval fusion and highly conflicting data, an improved combination rule based on the D-S evidence theory is developed. Then, fuzzy prior probability for each risk factor can be generated from fused intervals and fed into a fuzzy BN model for fuzzy-based Bayesian inference, including predictive, sensitivity, and diagnosis analysis. Furthermore, a case study is used to demonstrate the feasibility of the proposed risk analysis. A comparison of risk analysis based upon the hybrid improved D-S, classical D-S, and arithmetic average method is illustrated to show the outstanding performance of the developed approach in fusing multisource information with ubiquitous uncertainty and conflicts in an efficient manner, leading to more reliable risk evaluation. It is concluded that the proposed risk analysis provides a deep insight on risk control, especially for complex project environment, which enables to not only reduce the likelihood of failure ahead of time but also mitigate risk magnitudes to some degree after the occurrence of a failure.Ministry of Education (MOE)Nanyang Technological UniversityThis work was supported in part by the Ministry of Education Tier 1 under Grant M4011971.030 and in part by the Start-Up Grant at Nanyang Technological University, Singapore under Grant M4082160.030