Effiziente und wandelbare Tragwerke für Hochhäuser aus Stahlbeton
Author: Kevin M. Rahner
Language: German
DOI: 10.3929/ethz-a-010603540
Abstract
This thesis is intended as a contribution to the development of adaptive and efficient reinforced concrete structures of high-rise buildings. Most often the external appearance of high-rise buildings is determined by an architectural competition and the internal layout is determined by its defined use. Within this tight framework the structural system is designed under the constraint of time and cost. Contrarily, if a structure can be freely adapted to a variety of uses during its entire lifespan, it is referred to as adaptive. Based on this premise, the structural system is subdivided into hierarchical layers and classified into permanent and temporary components. The development of the hierarchically lowest layer provides the design constraints for the next layer. A concept for flexible structures is thereby developed presenting fundamental possibilities and approaches through novel processes.
Chapter 2 describes the historical development of high-rise buildings. The primary structural support systems are discussed based on reference projects. A definition for the efficiency of the high-rise buildings’ bracing systems is proposed and used later in this thesis. The viability of this definition is discussed considering a variety of examples of commonly used structural systems.
Chapter 3 applies the concept of general sustainability to the structure of high-rise buildings. The most important correlations are derived from available structures and summarized in a list of requirements for the development of flexible structures.
On this basis chapter 4 develops the model for a flexible high-rise building. At first, general design strategies and constraints are defined. Apart from the external appearance, the chapter deals especially with the vertical and horizontal access possibilities and the spatial configuration of the interior building volume. Next, floor plans are developed for a variety of usages and their implementation is verified within flexible volumes. The advantages of reinforced concrete in high-rise buildings and construction methods that enable an efficient floor construction sequencing are discussed. Subsequently the different hierarchical layers of the structure are determined. Starting with the analysis of available floor systems, a system for further processing is developed. The development of powerful secondary structures which are an interface between the floor systems and the permanent megastructures constitutes the next step. Megastructures can be defined as the spine of the high-rise building and are structurally designed for highly optimized efficiency. The feasibility of the hierarchical layers is analyzed and verified by designing essential structural connections and details.
At the end of the chapter there is an image library of interior and exterior impressions.
Chapter 5 discusses - based on detailed drawings - the structural questions about the feasibility of future change of use.
Chapter 6 describes the evaluation and classification as well as the possibilities for variation of the developed structural system, including the approach in applications.
Chapter 7 contains the summary of the thesis, discusses limitations of the results and provides recommendations for further investigations and developments.