| HKUST |
Automated Optimization and Clash Resolution of Steel Reinforcement in RC Frames Using Building Information Modeling and Hybrid Genetic Algorithm |
Thesis |
08/2017 |
Mohit MANGAL |
Reinforced concrete (RC) is widely used in building construction. Steel reinforcement design for RC frames is a necessary and important task for designing RC building structures. Currently, steel reinforcement design is performed manually or semi-automatically with the aid of computer software. These methods are error-prone, time-consuming, and sometimes resulting in over-design or under-design. In addition, clashes of steel reinforcement bars are rarely considered during the design stage and they often occur in beam-column joints on site nowadays. Additional time and manpower are often needed to resolve these clashes in an ad-hoc manner. Sometimes, it is impossible to resolve clashes without moving the steel reinforcement bars and redesigning steel reinforcement layout. Therefore, this research aims to develop a framework for automating the steel reinforcement design process for RC frames using the building information modelling (BIM) technology. BIM has been increasingly popular in the architecture, engineering and construction (AEC) industry for some years, but its use in structural design is still limited to extracting construction design and clash detection. However, BIM models provide much geometric and functional information and can be used for steel reinforcement optimization and clash resolution as well.
This research presents an automated steel reinforcement optimization framework with modified version (considering clash resolution) based on the BIM technology. The first framework uses information from a BIM model to intelligently suggest the number, size and arrangement of three types of steel reinforcement (i.e., tensile, compressive, and shear) with minimum steel reinforcement area. The framework uses the developed hybrid Genetic Algorithm-Hooke and Jeeves (GA-HJ) approach to optimize the steel reinforcement according to the loading conditions, end-support conditions and geometry of the RC member (RC beam or RC column). The developed GA-HJ approach increases the efficiency as well as the quality of the optimum solutions. The modified version of the framework is then developed to utilize and integrate the 3D spatial information of RC frame from a BIM model to provide clash-free and optimized steel reinforcement design. The modified framework uses a two-stage GA approach to provide clash-free, optimized, constructable, and design code compliant steel reinforcement design. Overall, the developed frameworks provide fast and error-free steel reinforcement design with the minimum area of steel reinforcement when compared with currently available steel reinforcement design approaches. In addition, the developed GA-HJ approach can be modified and used to support other building design optimization problems in future. |
N.A. |
| HKUST |
Evaluation of the BIM Adoption for Civil Infrastructure and Development of a 5D BIM Financial Decision Making Framework |
Thesis |
08/2015 |
Qiqi LU |
Building Information Modeling (BIM) has been widely adopted in the building industry. However, the application of BIM in civil infrastructure facilities, sometimes referred to Civil Information Modeling (CIM), is relatively lacking and slow. Researchers and practitioners are increasingly putting efforts into CIM study and implementation, but so far there is no comprehensive review of their efforts in this regard. Such study can help the academia and industry find the gaps and identify future research direction. Therefore, this work firstly presents a framework to evaluate the current practices of CIM adoption for various civil infrastructure facilities. In this study, civil infrastructure facilities were divided into nine categories for evaluation and the efforts with regard to CIM adoption for each infrastructure category were evaluated in six aspects. This study summarizes the results of 171 case studies and 62 academic papers on CIM. Based on the evaluation and comparison results, research gaps and future direction are identified. For example, CIM uses for detailed design and documentation phase and O&M phase like 5D cost estimation, are seldom conducted and studied.
5D BIM has been studied in academic research and implemented in industry. However, existing studies on 5D BIM focus on cash outflow estimation rather than cash inflow analysis and project financing. This thesis proposes a 5D BIM-based framework for cash flow analysis and project financing. This framework considers contract types and retainage to estimate cash inflow, and cash outflow patterns for equipment, manpower and materials to accurately estimate cash outflow. Project financing scenarios can also be evaluated using the framework. One building case and one bridge case are demonstrated to validate the proposed framework by considering various what-if scenarios. The framework can help contractors analyze the cash flow and make appropriate decisions for different design and payment scheme alternatives in various types of construction projects. |
N.A. |
| HKUST |
A BIM-based Framework for Site Layout Optimization and Material Logistics Planning on Congested Construction Sites |
Thesis |
08/2015 |
Srinath KUMAR |
Urban construction projects are characterized by the lack of available space on construction sites. Due to the confined nature of such sites, construction materials, equipment and manpower must be managed within the same area, leading to frequent conflicts. As a result, the construction site layout and material logistics plans should be carefully coordinated to ensure a seamless flow of materials, equipment and labor. Existing studies focus on developing systems to address construction site layout planning (CSLP) and material logistics planning (MLP). However, such systems fail to address the mutual impacts and inter-dependencies between the site layout and material logistics plans. Furthermore, existing systems suffer from a lack of automation and inability to address construction delays. Therefore, this research aims to develop a framework for planning the site layout and material logistics on construction sites making use of building information modeling (BIM) technology. BIM has been used in the construction industry for over a decade, but its use in construction planning is still limited to clash detection and 4D simulation. BIM models however, are rich information sources and can be used for construction site layout and material logistics planning as well.
This research presents an automated CSLP framework and a MLP framework that are developed based on BIM technology. The first framework utilizes information stored in BIM models to estimate the size, type and number of temporary facilities required by a construction project during different time intervals. By leveraging the functionality offered by the Autodesk Revit application programming interface (API), several of the computations are automated, significantly reducing manual effort. The second framework is designed to integrate material quantity information from BIM models with construction progress data and material delivery information. This framework coordinates material logistics along with the site layout, giving special emphasis on responding to construction delays. The two frameworks together can be used to facilitate CSLP and MLP on congested construction sites. |
N.A. |
| HKUST |
A Building Information Modeling Framework for Waste Estimation and Embodied Carbon Calculation of Buildings |
Thesis |
08/2012 |
Yinghui MA |
The construction industry is a major consumer of natural resources and energy, and a major contributor of waste and carbon emissions. Many countries have taken initiatives to reduce the negative environmental impacts in terms of waste and carbon emissions caused by construction activities; however, implementations of those strategies are often based on experience and heuristics rather than quantitative data. The value of estimating and evaluating construction and demolition (C&D) waste and carbon emissions in the construction industry has been indicated in literature. Nevertheless, tools that can accurately and conveniently estimate the amount of the waste from construction projects are lacking. On the other hand, current carbon emission analysis tools mostly focus on the estimation of operational carbon. Although embodied carbon (EC) of building materials has shown increasingly important in carbon emission analysis of buildings, the current tools that estimate EC are still primitive and not automated.
Therefore, this study aims to develop a framework for a lifecycle evaluation of waste and carbon emissions of buildings leveraging the building information modeling (BIM) technology. BIM represents the process of development and use of a computer generated model to simulate the planning, design, construction and operation of a building facility. BIM has been increasingly used in the architectural, engineering and construction industry for building performance analysis and construction planning. However, the use of BIM for estimation and planning of C&D waste and EC is still lacking. This thesis presents the automated BIM-based C&D waste estimation system and the automated BIM-based EC estimation system that the author has developed. The first system was designed to extract material and volume information through the BIM model and integrate the information for detailed waste estimation and planning. The second system was designed to integrate extracted material and element information with external carbon inventory databases for embodied carbon and energy estimation.
With the two systems, decision making could be facilitated among clients, architects, engineers, and other stakeholders. The systems can also be used combined with current tools to perform a lifecycle analysis. As the BIM technology has been increasingly adopted and digital building information models will likely to be available for most buildings and even infrastructures in the future, our systems can be applied in various projects. |
N.A. |
| HKUST |
BIM-based Automatic Piping Layout Design and Schedule Optimization |
Thesis |
08/2020 |
Jyoti SINGH |
Piping system is one crucial component in civil infrastructure that is designed to collect and transport fluid from the various sources to the point of distribution. The design, manufacture, coordination, scheduling, and installation of pipe systems is an important and necessary task and is one of the most time-consuming and complicated jobs in any piping project. Therefore, it is important and necessary to perform pipe systems design and scheduling efficiently. Better understanding of the complex design logic and installation options of a pipe system can enhance the reliability of designing and scheduling, which is crucial to achieve smooth and steady design and schedule flow. An efficient designing and scheduling of piping systems become more and more challenging due to various constraints such as physical, design, economical, and installation constraint. Current practice in the architecture, engineering and construction (AEC) industry involves pipe system design and installation as per enforced design codes, either by manual calculations, or by partial automation using computer-aided design software. Manual calculations are based on the experience of consultants and design codes, which is labor intensive, time consuming, and unadaptable to changes, and often leads to mistakes due to tedious nature of pipe design and coordination problems and the numerous calculations and decision-making involved. Therefore, complete automation with design and schedule optimization are required to economically plan pipe system design layout and generation of installation schedule.
Nowadays, Building Information Modelling (BIM) has been increasingly applied for architectural and structural design in civil engineering, especially in the building sector, since BIM have advantages for digital representation and information management. BIM technology is used to capture the 3D geometric and semantic information of the ceiling space, building components and pipe system information and parameters. BIM technology is used to capture the valuable information from 3D models to assist time based 4D modeling. However, existing research of BIM application for piping system design in building sector is lacking. To tackle the limitation of existing research, this thesis aims to develop an automated BIM-based approach for pipe systems design and schedule optimization.
For the design of pipe system layout, various factors such as building space geometry, system requirements, design code specifications, and locations and configurations of relevant equipments are considered. A framework based on building information modeling (BIM) for automatic pipe system design optimization in 3D environment. Heuristic algorithms are modified and used in a directed weighted graph to obtain the optimal feasible route for pipe system layout. Clashes among pipes and with building components are considered and subsequently avoided in the design optimization. The developed framework considers one-to-one, one-to-many, many-to-one connections of the pipe network routing. Comparison between heuristic routing algorithms is also presented in this research.
For installation schedule generation, this research proposes a new approach to automate pipe installation coordination and schedule optimization using 4D BIM. Category-based matching rules are used to automate the pairing and integration between 3D BIM models and installation activities. Constraint based analysis by sequence rule is developed to generate favorable sequence and coordination between pipe systems. Heuristic algorithm is adopted to optimize the generated practical schedules based on formulated objective function. All developed BIM-based framework and approaches are illustrated with related examples. Compared to current practices, these proposed approaches significantly reduce the time and cost for pipe system design layout and generating installation schedule.
This research has three parts. The first part is background study and literature review on pipe systems design and scheduling. The second part applies BIM-based framework to design piping system, including the following three studies: (1) an automated single pipe system design using modular approach, (2) multiple pipe system layout design optimization, and (3) comparison of developed approach with other optimization methods. The third part applies BIM-based framework for piping coordination and scheduling optimization |
N.A. |
| HKUST |
Application of Mixed Reality Technology for Operations and Maintenance of Building Facilities |
Thesis |
08/2019 |
Keyu CHEN |
The architecture, engineering, construction and operation (AECO) industry has been widely regarded as a highly resource consuming industry. Among different stages of the AECO industry, the operations and maintenance (O&M) lasts the longest in the lifecycle of a building and incurs more than 85% of the total costs, indicating the importance of optimizing management and improving efficiency during O&M. However, it was indicated that two-thirds of the estimated cost of facility management is lost due to inefficiencies during the O&M stage. With current approaches for O&M activities, it is difficult for people to directly visualize and update information of building facilities and many¬ facilities are hidden (e.g. ventilation ducts above ceilings and water pipes under floors). Therefore, this research aims to apply innovations to improve efficiency during the O&M stage. In recent years, professionals begin to realize the practical value of mixed reality (MR) technology, which can aid in various tasks during O&M. Through integrating virtual information with the real world, MR makes the information of users surrounding facilities readable and manipulable. However, there are two major limitations while implementing MR in O&M: (1) All existing methods for MR spatial registration have their own limitations in either accuracy or practicality. (2) There is a lack of efficient methods for data transfer from BIM to MR, which limits the functionality and complexity of MR applications. To tackle these limitations, this research develops an MR engine that can achieve accurate and robust MR spatial registration and efficient data transfer from BIM to MR.
For the development of the MR engine, an indoor localization approach is proposed for MR spatial registration. A transfer learning technique named transferable CNN-LSTM is proposed for improving the accuracy of localization and reducing Wi-Fi fingerprinting’s vulnerability to environmental dynamics. A deep learning approach that combines convolutional neural network (CNN) with long short term memory (LSTM) networks is first proposed to predict the locations of unlabeled fingerprints based on labeled fingerprints. Then the transferable CNN-LSTM model is derived from the CNN-LSTM networks based on transfer learning to improve the robustness against time and devices. The proposed transferable CNN-LSTM model is tested and compared with some conventional approaches and even some transfer learning approaches. Another part of the engine focuses on efficient mechanisms for BIM-to-MR data transfer. An ontology-based approach is proposed for transfer of semantic data. For geometric models, building components are classified into four types according to their different features and different model simplification algorithms are proposed accordingly. The algorithms were first tested with single components, and then a whole building was used to evaluate the overall performance of the developed mechanisms. As illustrated in the tests, the developed mechanisms can efficiently transfer both semantic information and geometric information of BIM models into MR applications, thus reducing the time for model transfer and improving the fluency of corresponding MR applications.
The developed MR engine is then applied to facility maintenance management (FMM) and emergency evacuation. To improve the efficiency of FMM, a BIM-based location aware MR collaborative framework is developed, with BIM as the data source, MR for interaction between users and facilities, and Wi-Fi fingerprinting for providing real-time location information. An experiment is designed to evaluate the effectiveness of the developed system framework. For emergency evacuation, a graph-based network is formed by integrating medial axis transform (MAT) with visibility graph (VG), with the addition of buffer zones. Closed-circuit television (CCTV) processing techniques are also developed to monitor the flow of people so that evacuees can avoid congested areas. An Internet of things (IoT) sensor network is established as well to detect the presence of hazardous areas. With the constructed graph-based network, congestion analysis and environment index of each area, an optimal evacuation path can be obtained and augmented with MR devices.
This research develops an MR engine that can improve the accuracy and robustness of conventional Wi-Fi fingerprinting based MR spatial registration and efficiency of BIM-to-MR data transfer. The developed MR engine has been implemented in FMM and emergency evacuation, illustrating the potential of the proposed approaches in improving the efficiency of O&M activities. |
N.A. |
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