Virtual Construction: 4D Planning and Validation.
Visual 4D modelling and planning technologies are becoming increasingly important in complex construction programmes facing the problems of advanced communication among stakeholders, better utilization of critical resources, and effective spatio-temporal coordination of works. Popular 4D tools and systems provide basic functionalities to simulate project schedules in virtual environments and to identify simple conflicting situations caused by collisions and interferences of construction elements and equipment units. Due to their complexity the collisions are usually detected in pseudo-dynamic mode assuming all the changes occurring in discrete time moments. Ultimately, it enables to anticipate and avoid potential problems at earlier phases and to reduce risks and waste at final construction phases often undergone to delays and reworks. The aim of this paper is to systemize possible spatio-temporal conflicts and to present advanced methods for more comprehensive and trustworthy validation of project schedules. For this purpose, an extended test suite is proposed by composing four complementary groups, namely: clash, join, workspace and path tests. Compared to usual clash testing, the introduced test suite helps to identify non-trivial defects like missing of supporting neighbouring elements, unavailability of required workspaces and absence of collision-free paths to deliver the elements to destination locations. For each group of tests the formal mathematical criteria and efficient computational strategies are presented and discussed. It’s essential that they do not need detailed specifications of testing use cases and can be applied for large-scale construction projects simulated in pseudo-dynamic mode. Conducted computational experiments have proved the effectiveness and the feasibility of the proposed 4D planning and validation methods.
CONVR'2011: Proceedings of the 11th International Conference on Construction Applications of Virtual Reality, 3-4 November, 2011, Bauhaus-Universität Weimar, Germany. Publisher: Bauhaus-Universität Weimar, 2011. Pp. 295-308.