4D-Based Workspace Conflict Detection in Prefabricated Building Constructions

Abstract

A number of parallel lifting operations may take place simultaneously on a prefabricated construction site, likely resulting in workspace overlapping, which is likely to delay the project and even cause accidents. This indicates that the workspace is becoming a deficient resource, which needs to be addressed in project scheduling. To identify the workspace conflict, a 4D conflict detection approach was proposed in this study. First, the allocation of entity space, safety working space, and efficient working space were differentiated based on the characteristics of the prefabricated construction project, followed by analysis of the impacts of three kinds of space interference. Consequently, a workspace generation framework was established that considered both the motion of construction machinery and the requirement of laborers, and then the severity evaluation formula was established accordingly. Based on that, a hybrid axis-aligned bounding box (AABB) and orientational bounding box (OBB) algorithm was proposed to detect workspace conflicts. Finally, workspace conflict detecting and evaluating modules were implemented using Navisworks SDK. Empirical results showed that this algorithm is able to forecast the time–space conflicts accurately for prefabricated construction projects. Benefiting from the framework proposed in this research, project managers can detect workspace conflicts in advance and optimize the schedule to avoid schedule delays and extra cost, as well as to improve safety.