Tall Timber Buildings - concept studies

In recent decades, sustainability issues have become an increasingly important issue in the construction industry. When one has managed to reduce energy consumption in the finished building through better installation solutions and climate shells, the interest in materials and energy consumption during the construction phase has gained a greater importance where wood in several studies has proved to be a favorable alternative. This, together with an increasing urbanization, leads to an increasing interest in tall timber buildings (20+ floors).

The purpose of the project is to show different possibilities for designing a 20+-storey building with load-bearing structure of timber and building knowledge of the issues among the participating actors. Important areas for the design of the building will be fire, LCA, design calculations related to both static and dynamic loads, eg vertical and horizontal deformations caused by static load and wind load. For some areas, especially deformation in the serviceability limit state, new calculation models will have to be developed and implemented in a form that is useful for practicing engineers.

The project will be carried out as a concept study of a building with 20+ floors designed with bl. a column-beam system in glulam, systems based on solid wood panels and light beams in timber. In the project, several actors collaborate with different skills in designing concept buildings. By carrying out a practical project planning and conducting planning meetings with all parties involved on a number of occasions during the project period, a knowledge transfer between all the actors will be achieved. The research performers will contribute as a support in the process with detailed knowledge in different areas such as Eurocode (loads, wooden constructions), FE modeling, fire safety and LCA.

It is known that there is lacking knowledge of certain design aspects and where more detailed experiments and models are needed to be able to carry out the design. This applies mainly to issues concerning deformation both in vertical and horizontal joints. The computational models that need to be created will therefore treat areas such as vertical deformations (including the effects of moisture), static horizontal deformations and dynamic deformations (vibrations/sway). In particular, the joints between the various elements and properties such as strength, stiffness, ductility and damping will be important. In order to investigate the properties of the joints, laboratory tests will be carried out where these properties are studied. These data will then be used in Finite element models to describe the entire building's structure. With the help of "sub-structuring" strategies, it is possible to reduce the size of the models but still produce representative results. Field measurements of dynamic properties (damping, eigenmodes and natural frequencies) will be carried out on existing buildings with similar building systems. These measurements will be used for calibration of the models before they are used to study the properties of the concept buildings. These models will then be implemented in a form useful for practicing engineers.

The project will result, among other things, in the following:

• Knowledge among the participating actors on issues around tall timber buildings

• More architects and designers with experience of designing tall timber buildings

• Best practice guide describing opportunities with different building systems in the construction of tall timber buildings.

• Suitable models for calculating mainly deformations (vertical and horizontal) and dynamic properties of tall timber buildings

• Calculation tools for designers for tall timber buildings

• Development of existing timber building systems for multi-storey houses

• Environmental performance for tall timber Buildings.