The 200 m timber tower - A study of building geometry and construction feasibility

Abstract

There are a lot of building materials used in the building sector such as concrete, steel and timber, each with its own advantages and disadvantages. For a long time, timber has not been seen as a common material for advanced structures in civil engineering field and architecture field. With the continuous development of engineered wood products, timber has nowadays become a more common building material used for multi-floor buildings. The 20th century witnessed a construction boom in tall buildings worldwide. So far, the knowledge of how to build a high-rise building with a timber structure is still limited. The current world’s tallest timber building is Mjöstornet in Norway, with a height of 85m, which is only about one-tenth of the world’s highest building Burj Khalifa in Dubai. The main objective of this report is to study and evaluate different building geometries with main concerns about economy, environment aspect and structural performance of a 200m timber building. The building site is assumed to be 30m x 30m and is in Gothenburg with the ground condition of solid rock. The study divided into two main steps and was mostly performed in Grasshopper and Karamba 3D. In the first step two concepts were selected through an evaluation based on the results of deflection, rental area and building mass of various concepts. In the second evaluation several criterions were added such as dynamic performance, base support force and building mass per rental area ratio to find a promising concept. The final proposal is a diagrid structure in hyperboloid form and was chosen through comprehensive evaluation. This geometry has significantly better performance regarding dynamic performance compared to all other diagrid structures in convex form and traditional braced frame structure that has been studied, though providing much less rentable areas.