Shadow cost optimization of the main bearing construction of industrial halls

Abstract

The purpose of this thesis is to determine the most optimal material use and configuration of structural elements with regard to minimizing shadow costs associated with the main bearing construction of industrial halls. Central themes in thesis are reusability, parametric modelling and generative design.

The construction sector is responsible for a large amount of pollution due to its high energy consumption during extraction and transportation of raw materials. Paradoxically, this offers the construction sector a unique opportunity to notably decrease its negative environmental impact. More and more industrial halls are built due to an increase in online shopping and the subsequent need for the distribution of consumer goods. However, the current inefficiency in shadow cost reductions of main load bearing elements presents a problem for the decrease in harmful emissions as a consequence of construction.

Shadow costs associated with structural elements decrease as a result of reuse. Connection types have been identified as the most influential factor for reusability. Therefore, a connection reusability factor was developed which was given according to four material independent criteria. Subsequently, a corrected shadow cost (CSC) can be calculated by multiplication of this reusability factor with the original ECI. However, this method is experimental and is not sufficiently corroborated by relevant literature yet.

A parametric model of an industrial hall was constructed in Dynamo which could be optimized using a genetic algorithm in Autodesk generative design in order to minimize the shadow costs of the design. No biogenic carbon storage was accounted for during these optimizations and only single span hinged construction elements were assessed. Furthermore, all designs were assumed to be located in a rural part of Dutch wind zone II and no fire protection measures were accounted for in the ECI or price of the designs.

Based on these assumptions, several conclusions could be drawn from the optimization of an arbitrary hall and two case studies. For the boundary conditions that were selected for the arbitrary hall, steel elements performed best with regard to the total ECI value as well as the corrected shadow costs. Contrary to popular belief, timber elements performed best in terms of price. A combination of both materials therefore has a high probability of resulting in the most cost effective ECI optimization. The results from the first case study indicate that the ECI of an existing hall could be reduced by 16 % as a result of the optimization methodology as presented in this thesis. The second case study was not accurately comparable enough to the optimized hall as a result of large differences in the connection types that were used.

The results that are presented in this thesis are based on specific loads, connection types and boundary conditions and configuration of the halls. The conclusions that are drawn in this thesis are therefore only valid in case similar halls with similar boundary and load conditions are assessed.