BIM-based automatic piping layout design and schedule optimization

Pipe systems are important in buildings and civil infrastructure that is designed to collect and transport fluid from various sources to the points of distribution. The design, spatial coordination, and installation schedule of pipe systems are 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 system design and installation 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 installation flow. Efficient pipe system design and scheduling for pipe systems installation become increasingly challenging due to various constraints such as physical, design, economical, and installation constraints. Current practices in the architecture, engineering and construction (AEC) industry involve 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 system design, coordination and sequencing 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 and generation of pipe system 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 has advantages for digital representation and information management. BIM technology is used to capture the 3D geometric and semantic information of 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 pipe system design and installation schedule generation in the building sector is lacking. Therefore, this thesis aims to develop an automatic BIM-based framework for design and installation schedule optimization of pipe systems. In order to efficiently and economically design pipe systems this research focuses on two major aspects of the design process: pipe system design which refers to the determination of detailed specifications (routing and sizing) of pipe system and its components and layout design for multiple pipe systems which refers to spatial coordination and arrangement of multiple pipe systems in the confined space under various kinds of constraints. For the pipe system design, a building information modeling (BIM)-based framework for the automatic design optimization of pipe system in 3D environment is developed. The framework integrates pipe routing design and pipe sizing design to generate and design pipe system based on project requirements. Various factors such as building space geometry, system requirements, design codes specifications, and locations and configurations of relevant fixtures and equipments are considered. BIM technology is used to capture geometric and semantic information of the space and components pertaining to a building. The 3D A* algorithm is adapted in a directed weighted graph to find an optimal route for any single pipe system. Clashes of pipes with building components are examined and avoided during design optimization, resulting in the mapping of an optimal, clash-free pipe route for a pair of supply and demand point. When routing the pipe network, the framework considers one-to-one connections. In addition, it formulates a standardization approach to standardize pipe system components. Functionality of the framework is tested and demonstrated through an illustrative example. With the adoption of deve oped framework, time and effort for pipe system design is significantly reduced and the design is optimal and clash-free with standardized components. Besides the optimal pipe system design, the developed framework also makes the information flow of projects more efficient. For the layout design of multiple pipe systems, a BIM-based framework of heuristic search method based on the 3D A* with Simulated Annealing algorithm is developed. The 3D A* algorithm is modified according to the physical, design and economical requirements of layout design and is used to generate a single pipe system route automatically. The simulated annealing algorithm is used to approximate global optimization in a large search space for layout design optimization of multiple pipe systems based on formulated objective function. The algorithms also consider DFA principle to curtail installation cost at the latter stage. Clashes between pipe systems and building components are considered and subsequently avoided in layout design optimization. One-to-many and many-to-one connections for pipe systems are supported in the developed layout design framework. In addition, the framework compares layout design optimization of multiple pipe systems using constant grid size graph and variable grid size graph. The developed BIM-based framework for layout design of multiple pipe systems is illustrated with a real world example. The result shows that the developed framework can generate optimal and clash-free layout design for multiple pipe systems. Compared with conventional methods, the developed framework significantly reduces the time and cost for layout design of multiple pipe systems. Several approaches are available to find the best solution for layout design optimization problem. This research implements and compares heuristic search methods for layout design optimization of multiple pipe systems based on formulated objective function. Algorithms are developed based on a directed weighted graph according to the physical, design, economical and installation requirements of layout design. Clashes between pipe systems and building components are considered and subsequently avoided in layout design optimization. Based on the developed algorithms, Simulated Annealing (SA) algorithm is used to approximate global optimization in a large search space for layout design optimization of multiple pipe systems. As for layout design, Dijkstra algorithm and two heuristic algorithms namely 3D A* and Fruit Fly Optimization algorithm (FOA) are implemented and compared to obtain the multiple pipe system layout design. The result shows that 3D A* provide best result with minimum total layout cost for multiple pipe systems which is same as Dijkstra algorithm and in lesser time. For pipe system installation schedule generation, this research proposes a new framework for automatic installation coordination and schedule optimization of pipe systems using 4D BIM. BIM technology is used to capture valuable information from 3D models to assist time based 4D modeling. Category-based matching rules are used to automate the pairing and integration between the 3D BIM models and installation activities. Constraint based analysis by sequential rule is developed to generate favourable sequence and coordination between pipe systems and Simulated Annealing is adopted to optimize the generated practical schedules for installation as it often accepts and checks worse solutions and provides global solution based on formulated objective function. An illustrative example is presented to validate the developed framework and the result shows that the developed framework can generate a constrained-free installation sequence and an optimal schedule. Compared with conventional methods, the developed framework significantly reduces the time and enhances accuracy for pipe system installation schedule generation.