Kyungki Kim

Automatic design and planning of scaffolding systems using building information modeling

Considering their significant impact on construction projects, scaffolding as part of the temporary facilities category in construction must be thoroughly designed, planned, procured, and managed. The current practices in planning and managing scaffolding though is often manual and reactive, especially when a construction project is already underway. Widespread results are code compliance problems, inefficiency, and waste of procuring and managing material for scaffolding systems. We developed a rule-based system that automatically plans scaffolding systems for pro-active management in Building Information Modeling (BIM). The scope of the presented work is limited to traditional pipe and board scaffolding systems. A rule was prepared based on the current practice of planning and installing scaffolding systems. Our computational algorithms automatically recognize geometric and non-geometric conditions in building models and produce a scaffolding system design which a practitioner can use in the field. We implemented our automated scaffolding system for a commercially-available BIM software and tested it in a case study project. The system thoroughly identified the locations in need of scaffolding and generated the corresponding scaffolding design in BIM. Further results show, the proposed approach successfully generated a scaffolding system-loaded BIM model that can be utilized in communication, billing of materials, scheduling simulation, and as a benchmark for accurate field installation and performance measurement.

Integration of Safety Risk Factors in BIM for Scaffolding Construction

of US workers in the construction industry work on scaffolding. Of these workers 4,500 are injured and 50 die every year due to scaffold-related accidents. Proper safety management such as scaffolding safety inspections can support the hazard mitigation and prevention. This paper shares the results of a study of the levels of safety risk at each stage of the scaffoldings project life cycle for building a masonry wall and how these risks and related mitigation suggestions can be applied to Building Information Models (BIM). Safety is integrated with 4 dimensional (4D) BIM by linking the scaffoldings safety risks and mitigations with the project schedule. The 4D BIM can be used as a tool for the safety management to monitor and diminish the safety hazards associated with scaffolding work. Four different stages of research were conducted to determine the safety risks and implement them, and the mitigations, into BIM. (1) Determine the activities associated with working on scaffolding. (2) Collect data from industry professionals about the likelihood and severity of safety hazards at each stage of the scaffolding project life cycle. (3) Establish the safety risks using the collected data and a standardized algorithm. (4) Incorporate the safety risks into BIM and provide mitigation recommendations. As a result, the 4D BIM can be used throughout the project planning and construction progress to inform the safety management of activities associated with the scaffolding that have high safety risks and assist safety management in implementing preventative measures according to given mitigation recommendations.

Construction-specific spatial information reasoning in Building Information Models

In recent years, there have been significant advances in modeling technology for object-oriented building products. However, the building models are still lacking of providing construction-specific spatial information required for construction planning. Consequently, construction planners visually analyze building product models and derive geometric characteristics such as bounded spaces and exterior perimeter to develop detailed construction plans. Such a process presents fragmented information flows, from building product information to construction planning, that rely on subjective decisions of construction planners. In order to overcome these drawbacks, this research proposes a geometric reasoning system that analyzes geometric information in building designs, derives the construction-specific spatial information, and uses the information to assist in construction planning. The scope of presented work includes detecting work packages formed by faces during construction, such as large work faces and bounded spaces, and using information in the work packages directly to support planning of selected indoor construction activities. The main features of the proposed system named Construction Spatial Information Reasoner (CSIR) include a set of relationship acquisition algorithms, building component relationship data structure, and interpretation of the relationship to support detailed construction activity planning. The relationship acquisition algorithms identify adjacency between building components that is stored in the relational data structure. Then, acquired adjacency relationships are transformed into a set of graphs that represent work packages. To implement the proposed approach, CSIR utilized a commercially-available Building Information Modeling (BIM) platform and the algorithms were imbedded to the BIM platform. For validation, CSIR was tested on a real commercial building. For interior ceiling grid installation activities, CSIR successfully detected existing work packages and analyzed the spatial characteristics impacting construction productivity. The major contribution of the presented research would be to enable a realistic analysis of building geometric condition that is not possible in current BIM and a seamless information flow from building product information to construction process plans. These can potentially reduce current manual and error-prone construction planning processes. Limitations and future research suggestions are also presented.

BIM-Based Planning of Temporary Structures for Construction Safety

Despite significant advances in Building Information Modeling (BIM) technology for construction planning, existing technology still lack the capabilities of planning and analyzing temporary structures. While temporary structures such as scaffolding and temporary stair towers significantly impact construction safety, they often do not appear in BIM. Temporary structure objects manually inserted into BIM cannot automatically generate information of their impact on construction safety. Understanding this deficiency, this research attempts to generate required temporary structures and analyze associated safety risk automatically. Specifically, this research focused on planning of temporary stair towers used during roof construction activities. For automation, a set of algorithms were created that analyze geometric conditions in BIM, generate required temporary stair towers, and analyze their impact on safety. The algorithms were imbedded into a commercially-available BIM platform and tested on an ongoing construction project. As a result, optimized locations and shapes of temporary stair towers and associated potential safety hazards were identified and visualized in BIM and schedule. The main contribution of this research would be to automatically perform more practical construction safety planning by incorporating temporary structures.

Multiobjective Construction Schedule Optimization Using Modified Niched Pareto Genetic Algorithm

AbstractA construction schedule must satisfy multiple project objectives that often conflict with each other. While several earlier approaches attempted to generate optimal schedules in terms of several criteria, most of their optimization processes were segmented into multiple steps. Owing to such a lack of simultaneous optimization, limited alternative solutions could be searched and some trade-offs between goals could not be identified. This paper presents an optimization approach that enables a simultaneous search for an optimal construction schedule in terms of three objectives: minimization of construction duration, cost, and resource fluctuation. A multiobjective optimization (MOO) approach was adopted to generate scheduling solutions considering all those objectives. To enable a simultaneous optimization, we propose a new data structure that can compute the performances of solutions in terms of all the objectives at the same time. A Niched Pareto Genetic Algorithm (NPGA) is modified to facilitate ...