Graduation Internship | Robustness in sustainable timber Structures

Robustness in sustainable timber Structures

Introduction

In 1968 a gas explosion led to a partial collapse of Ronan Point, a 22-storey residential block in London. An explosion in one apartment led to progressive collapse of an entire corner of the building with fatal outcome. This event resulted in a loss of public confidence in high-rise buildings. As a result, buildings codes have included measures to avoid disproportionate collapse. For buildings in consequence class 2 and 3 the Eurocodes prescribes strategies for ensuring sufficient robustness such as the application of tension ties, a check on notional element removal, and the use of key elements.

Currently, the building industry witnesses the increase of buildings in mass timber. However, the robustness of mass timber buildings is not yet fully understood. There are doubts that current prescribed rules by the Eurocodes are not fully suitable for mass timber structures. E.g., the above-mentioned robustness strategy of tensile ties implicitly relies on ductility and rotation capacity in the structure with timber structures lacking these properties.

The most appropriate strategy seems to be the notional element removal method. The removal of an element will induce a dynamic load on the structure as it suddenly will start to move before finding equilibrium. For a static analysis a dynamic amplification factor (DAF) may be applied the represent this phenomenon. The currently used DAF of 2 often leads to governing situations for the sizing of the structure. If analysis can demonstrate lower values to be realistic, this would be highly beneficial to design robust, but economic and sustainable timber structures.

Problem statement

Starting from Eurocode 5, investigate what dynamic amplification factor is appropriate for mass timber structures.

Methodology

• Understand robustness strategies

• Understand timber structures and timber mechanical properties

• Develop analytical (dynamic) models to investigate the DAF of a chosen load-bearing typology

Student profile

• You are interested in mass timber design, structural robustness and structural safety

• You have a thorough understanding of structural mechanics

• Understanding of non-linear behaviour of structures is a pre

• You are motivated to develop advanced analytical models

• You can think, work and report in a structured manner and break down problems into smaller solvable chunks

• Arup will view applicants as potential graduate/junior engineer in-take; an interest in Arup as a potential employer is required