Synchronous collaborative tunnel design based on consistency-preserving multi-scale models

Abstract

a b s t r a c tThe planning of large infrastructure projects such as inner-city subway tracks is a highly collaborative process in which numerous experts from different domains are involved. While performing the planning task, widely differing scales have to be taken into consideration, ranging from the kilometer scale for the general routing of the track down to the centimeter scale for the detailed design of connection points. Currently there is no technology available which supports both the collaborative as well as the multiscale aspect in an adequate manner. To fill this technological gap and better support the collaborative design and engineering activities involved with infrastructure planning, this paper introduces a new methodology which allows engineers to simultaneously manipulate a shared multi-scale tunnel model. This methodology comprises two main aspects. The first aspect is a multi-scale model for shield tunnels, which provides five different levels of detail (LoD) representing the different levels of abstraction required throughout the planning progress. The second aspect is a conceived collaboration platform, which enables simultaneous modifications of the multi-scale model by multiple users. In existing multi-scale approaches, where the individual representations are stored independently from each other, there is a high risk of creating inconsistencies, in particular in the highly dynamic collaborative planning context. To overcome this issue, the concept presented in this paper makes use of procedural modeling techniques for creating explicit dependencies between the geometric entities on the different LoDs. This results in a highly flexible, yet inherently consistent multi-scale model where the manipulation of elements on coarser LoDs results in an automated update of all dependent elements on finer LoDs. The proposed multi-scale model forms a well-suited basis for realizing the collaboration concept, which allows several experts to simultaneously manipulate a shared infrastructure model on various scales while using the different design tools they are accustomed to. The paper discusses in detail the principles and advantages of the proposed multi-scale modeling approach as well as its application in the context of collaborative tunnel design. The paper concludes with a case study of a large infrastructure project: a new inner-city subway tunnel in Munich, Germany.

Collaborative Multi-Scale 3d City and Infrastructure Modeling and Simulation

“…As a first step towards developing such consistency preserving product models, five different LoDs for modeling shield-tunnel facilities have been developed (Borrmann et al 2014). Figure B1 provides a 3D illustration of LoDs 2-5.…”

“…Main building block of the collaborative work is a client-serverbased platform which manages and controls all synchronous accesses to the centrally stored geometric model (Borrmann et al, 2014). The platform performs concurrency control on basis of procedural models, thus any modification issued by the different users never leads to inconsistent stages.…”

“…The basic concept is to make use of parametric modeling techniques to define dependencies between geometric entities on different LoDs in order to update the finer LoDs when objects on coarser ones are modified, thus establish a cross-LoD consistency preservation mechanism . The dependencies are stored in a system-independent manner as part of the neutral tunnel product model and can thus be interpreted across different CAD systems acting as clients of the collaboration system (Borrmann et al, 2014).…”

Automatic Detailing of Parametric Sketches by Graph Transformation

“…In [1], [3] and [4] the potential of this multi-scale approach is developed further and was successfully integrated into a comprehensive concept that permits the multi scale representations of building information models particularly directed to the modeling of shield tunnels. The challenge of a consistent representation throughout the multiple LoDs is addressed by the introduction of procedural modeling.…”

An improved LOD specification for 3D building models

“…We have considered their granular LODs when designing our refined specification. Borrmann et al (2014) provide an extended LOD specification for tunnels defining five LODs to create consistent multi-scale models and to use them for synchronous engineering collaboration. The LODs are discerned primarily by the list of railway elements that are acquired.…”