AENG 455 project 2 parametric building analysis adel allam islam obaya omar anas marwan omar mohamed badawy
aviva stadium introduction The architects viewed a selection of parametrically designed buildings including the Shanghai tower, the water cube, 30 st Mary Ax, and many others as they will be briefly viewed in this research. The Aviva stadium was selected for a number of reasons and primarily due to the parametric approach taken from the initiation to the completion of the project using parametric software. The approach allowed "detailed exploration of options and early identification and resolution of potential problems" (Shepherd et al. 68.)
project description project name: Aviva Stadium location: Dublin, Ireland constructed: May 2010 Architects: global architects Populous and Dublin based architects seat capacity: 50,000 seat s usage: international rugby and soccer fixtures and as a concert and events venue.
design objective The concept of the project was developed to allow for a responsive and empathetic to the surrounding fabric; its translucent form allows maximum daylight into the seating tiers as well as onto the existing buildings. The exterior skin "envelops both the roof structure and the facade structure, combing both elements into one controlling form." (Shepard et al. 169.) By the time the design concepts for the Aviva Stadium were being formulated, a parametric approach to building modelling was just starting to become integrated into commercially available CAD products, allowing parametric models to be shared amongst team members and fully integrated into established design practices. The coordination between structural egineers and architects was achieved through the parametric tools that has allowed for rapid response to design changes and provided full coordination between teams. The key to the success of the design was the sensitivity to the surrounding area. The north end of the Aviva stadium has a dramatic dip to the roof and seating to allow sunlight to the houses immediately behind and likewise at the south end to provide daylight to the buildings along Lansdowne Road. The environment and sustainability were a prominent part of the design process with rain water collected to irrigate the pitch and waste heat from the generators used to heat the water for the toilets. The glass and polycarbonate cladding ood the public areas of the stadium with natural light and even
Design Procces Design Process Stage 1 The concept and early design stages were done using a combination of 3D softwares .Rhinoceros was used first in creating the 3D form of the stadium and it helped the architects a lot in understanding the logic of the structure they were dealing with. They created the 3d model through a set of tangential arcs with different heights and loft between them to generate the form of the outer skin and the roof of the stadium .After understanding the logic of the structure , the architects rebuilt the 3D model using Bentley's Generative Components (GC) using a script that defines both architectural and structural elements according to a certain underlying geometry .This allowed the architects to have a parametric form having internally defined variables ,constrained geometry and outer parameters defined by the script. Stage 2 After reaching the controlled 3D parametric shape that was the guide in the later design stages, an excel sheet was established based on the GC Script. This excel sheet allowed both Architectural and Structural Engineers to work in parallel on the cladding system and the structure system respectively that was based on the geometric shape initially defined by certain parameters. During this stage, architects were exposed to cases where they had to change a little bit in the geometry of the shape, thus they had to update the collaborative excel sheet to allow structural engineers automatically recalculate their design through the use of the new parametric excel sheet. Envelope Geometry Development Modeling the form of the stadium depended on three main components which were the numeric data and parameters, the static geometry, and the GC script file. The excel data was implemented in the GC script while the static Geometry was all taken from CAD files. Below is a detailed description of
Design Procces the formation stages of the geometric shape. Stage 1 The first step was to draw a set of lines defining the outline of the roof and shape. Stage 2 Defining the inner and the outer geometry of the stadium Stage 3 Adding vertical dimensions to the lines drawn in step one so that each cross section of the skin consists of two straight lines and an arch Stage 4 Lofting between those cross-sections to form the 3D shape Stage 5 Converting the lofted shape into arcs again to help extract the dimensions for the plans and the sections of each part of the stadium
Design Procces STRUCTURE The concept of roof structure was developed after carrying out a series of trials and experimentations by using primitive parametric model. The structural engineering team along with the architects, worked on studies to shape the envelope a on both the architectural and structural levels. Analysis tools as Robot Millennium was used in the structural analysis phase followed by interactive discussion between the architecture and structural a to reach the optimum roof concept. GEOMETRY Horseshoe-shaped steel truss was used as the main roof supporter component. Several truss structures are interdependent by the use of secondary trusses transferring vertical load from the primary truss to columns. The structural design of such parametric model ensures that no clash between supportive structure and cladding or roof supports. The tertiary radial trusses used for load transfer between secondary trusses could entail more depth that increases its cost and makes the overall structure heavier. At this point, the structural team had to search for an “approach� to change truss dimensions to follow bending moment diagram.
Red Lines: Primary for roof support Green Lines: Radial Secondary Trusses Blue Lines: Tertiary Radial Trusses Grey Lines: Outer edge truss
Design Procces
NEW EQUATION FROM A NEW APPROACH.. A new equation was embedded within the parametric model; which considers a simple model made of tertiary trusses as a propped cantilevers (cantilevering out from the outer edge truss which provides rotational restraint, and resting on the primary truss with little rotational restraint) Individual trusses were shaped to have maximum depth at points of maximum bending moments. In this manner, each truss had to be fabricated individually. This equation saved material needed and resulted in less fabrication costs. At this phase, truss lacing and bracing were clearly defined and could be used for structure model generation. ANALYSIS The assistance of structural analysis software, made us feel more the importance of a parametric approach to structural modeling. So what are the benefits of the parametric approach? 1) Robot Millennium (Robot): a software used by the structural team in their design, It imports DXF files that GC can output, knowing that this approach only deals with the geometric data, so any additional information might be lost in this exchange. 2) A special C# program was written for Aviva Stadium within GC which exported data in Robot’s native text. This method maximizes the intelligence of the parametric model and limits man intervention in each stage. 3) Calculation of load on structure such as wind design loads from wind-tunnel tests acting on the surface of the structure. 4) The extension of GC to bring structural analysis into the family of parametric modeling tools facilitated a more collaborative approach to design. So what if this approach didn’t exist within the parametric framework? No sufficient data and analysis could be reached; accordingly, assumption would have been made that would defi-