HKU |
The Investigation on the Usage of Building Information Modeling (BIM) in Hong Kong |
Thesis |
04/2014 |
POON Ho Yu |
-- |
N.A. |
HKUST |
Automated Quality Assessment of Precast Concrete Elements Using 3D Laser Scan Data |
Thesis |
08/2017 |
Qian WANG |
Precast concrete elements are popularly adopted in buildings and civil infrastructures like bridges because they provide well-controlled quality, reduced construction time, and less environmental impact. To ensure the performance of complete precast concrete structures, individual precast concrete elements must be cast according to the as-designed blueprints. Any inconsistency between the as-built and as-designed dimensions can result in assembly difficulty or structure failure, causing delay and additional cost. Therefore, it is essential to conduct geometry quality assessment for precast concrete elements before they are shipped to the construction sites. Currently, the quality assessment of precast concrete elements is still relying on manual inspection, which is time-consuming and labor-intensive. Besides, due to tedious work, manual inspection is also error-prone and unreliable. Thus, automated, efficient, and accurate approaches for geometry quality assessment of precast concrete elements are desired. Nowadays, 3D laser scanning has been widely applied to the quality assessment of buildings and civil infrastructures because it can acquire 3D range measurement data at a high speed and high accuracy. However, existing research of laser scanning based quality assessment is mainly focused on simple-geometry elements, such as straight columns and rectangular concrete surfaces. There has been limited research on the quality assessment of precast concrete elements with complex shapes. To tackle the limitations of existing research, this research aims to develop automated, efficient, and accurate techniques for the geometry quality assessment of precast concrete elements using 3D laser scan data. The geometry quality assessment includes dimensional quality assessment, surface flatness and distortion assessment, and rebar position assessment.
For dimensional quality assessment, a dimensional quality assessment technique focusing on the side surfaces of precast concrete panels is developed. This technique aligns the laser scan data with the as-designed building information model (BIM), and extracts the as-built dimensions of the elements. Furthermore, an improved dimensional quality assessment and as-built BIM creation technique is developed to inspect the entire precast concrete element, rather than a surface only, and to automatically create a BIM model for storing the as-built dimensions for better visualization and management. As a supporting study, a novel mixed pixel filter is developed to remove noise data namely mixed pixels from raw laser scan data and to improve the dimension estimation accuracy. The proposed mixed pixel filter formulates the locations of mixed pixels, based on which the optimal threshold value is obtained to classify scan data into mixed pixels and valid points. Another supporting study is to investigate the influence factors for edge line estimation accuracy. Four influence factors are identified and the effect of each factor is analyzed based on numerical simulations. Implications are eventually suggested based on the analysis.
For surface flatness and distortion assessment, the developed technique identifies a few measures for both surface flatness and distortion. These measures are then automatically calculated from the laser scan data of the precast concrete surface for surface quality assessment. Furthermore, an automated rebar position estimation technique is developed to estimate the rebar positions for rebar positioning quality assessment. The technique can recognize individual rebars from the laser scan data of reinforced precast concrete elements and accurately estimate the rebar positions.
This research provides automated approaches for the quality assessment of precast concrete elements, which are able to greatly save the labor cost and time for quality assessment. In addition, the quality of precast concrete structures can be improved due to the faster and more economical quality assessment, thereby further promoting the adoption of precast concrete elements in the construction industry. |
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 |
BIM-based Daylighting and Energy Analysis on the HKUST Campus |
Report |
06/2019 |
Quazi Samira Rahman |
Building Information Modelling (BIM) based simulation models have been consistently used to automate prolonged building performance modelling processes such as thermal comfort assessment and energy analysis, enabling fast acquisition of results. Recent studies indicate that the demand for sustainable building facilities with minimal environmental impact is growing day by day. BIM is foreseen as a savior in terms of technology to unravel laborious engineering problems in a short span of time and analyse the conditions in a given space comprehensively as well as determine efficiency of built environment. This study presents how building information modelling can be utilized to address thermal comfort and energy efficiency in buildings in the operation phase, greatly contributing to achieving optimized solution. The study primarily deals with multi physical investigation on performance assured by ventilating system in supplying air quality and determining the potentials of comfort improvement and energy savings for the control of ventilation rate by proposing optimized method for relocating supply air duct. The focus of this thesis is limited to IAS lecture theatre at HKUST with respect to current set points for the supply air temperature. |
N.A. |
HKUST |
Risk Management in BIM Projects |
Report |
06/2020 |
SIO Wai Lam CHEONG Ka Yi |
The objectives of the project are to identify the risks with high risk level and mitigation with higher effectiveness in BIM industry. The survey was conducted to collect the data of risks and mitigations adopted by different groups of people. Overall analysis, by-group analysis and cross-group analysis were performed.
Thus, the risks were analyzed and discussed with two approaches - level of consequence and level of probability. The level of risk was identified combining these two approaches. The assumption and resolution of identified risks were discussed. Mitigation strategies with higher appropriateness were identified and relevant comments were made.
It is found that the level of risk of C6 (Poor participation / contribution from project team in BIM adoption) and M1 (Lack of adequate expertise in BIM) are extreme, and are very high for risk T6 (Design conflict / clashes in BIM was not revealed / unresolved), C1 (Unclear requirements (e.g. EIR / AIR / contract) of BIM uses and specifications), C2 (Unclear roles, responsibility and liability in BIM implementation). As for mitigation strategy, it is found that mitigation #1 (Clear Employer’s Information Requirement) and #11 (BIM Education for Project Team) were mitigation strategies with the 1st and 2nd ranking in appropriateness/effectiveness. Mitigation can minimize risk C6, and mitigation #11 helps to mitigate risk M1. |
N.A. |
HKUST |
Analysis and Evaluation of Indoor Ventilation and Energy Consumption Using Building Information Modeling |
Report |
06/2017 |
SONG Wenyi Qiushi WANG |
This project used Building Information Modeling (BIM) and BIM compatible software, Computational Fluid Dynamic (CFD), to analyze the indoor environmental quality of the current UG Hall VII building in HKUST under mechanical and natural ventilation. The results obtained from the software analysis were used for evaluating the indoor environment with green building standard BEAM Plus EB Ver. 2 Selective Scheme. Indoor environmental quality analysis and energy analysis on different air-conditioner usage scenarios and modified air-conditioning system were also conducted to investigate whether any modifications could give rise to the indoor environment that able to reach BEAM Plus standard while reducing energy consumption. We founded that turning on one air-conditioner in only one bedroom in a suite could achieve favourable indoor environment while reducing half of the energy usage on cooling. Also, changing the air-conditioning system from window-type air-conditioners to centralized system could also lower energy consumption on cooling while keeping a comfortable indoor environment. |
N.A. |