Cross laminated timber construction for resisting lateral loads on six level buildings

A worldwide interest in multi-storey timber buildings isexpected due to the environmental advantages of timberconstruction when compared to concrete and steel. Thispaper looks into three timber based systems forresisting lateral loads, on buildings to six storeys, in anattempt to achieve ‘open’ floor spaces. The lateral loadresisting systems are termed ‘frame’, ‘circular core’,and ‘shear walls’. They have been designed to withstanda typical wind load for an inner city environment. Onlyrelatively low stresses occur in the proposed threesystems and they can be built with timber that is mainlybelow ‘structural grade’ which is more economical.Reinforced concrete ‘socket’ foundations may be asimple solution in assisting lateral load resistingsystems’ columns to maintain their original locationsafter earthquake events. ‘Socket’ foundations preventthe bases from overturning, but ensure a degree ofenergy absorption due to yielding in the column basetiedowns and in the ‘engineering rubber’ lining betweenthe column and ‘socket’. The ‘circular core’ form is anefficient system and would be suitable for buildings thatare taller than six storeys, perhaps useful to ninestories.Architecturally, the most flexible arrangement would bea ‘frame’ system on each external wall. It would leavethe floor areas free except for internal columns; andwindows can be placed within the frame constructionallowing light to enter the building.The paper is an overview of possible lateral loadresisting systems from the viewpoints of structure,architecture and economics. Assumptions have beenmade, such as the deflections due to joint slippage beingaround the same as the elastic deflections, and theseassumptions will at some stage be researched and mademore accurate. The paper’s intention is to contribute tothe general discussion on the topic of timber multi-levelcommercial buildings.