Field Research on Soil-Structure Interaction of Sustainable Basement Using Mass Timber Panels

ABSTRACT: Resilient and mechanically stable cross-laminated timber (CLT), popular in mid-rise and high-rise buildings, is promising in basement construction for many advantages over concrete. The reinforced concrete basement is Canada's most popular solution in low-rise construction. However, these basements are known to have performance issues with the propagation of cracks and moisture migration problems. Wood-based foundations can provide a sustainable alternative solution for basement construction once mass timber produces lower carbon emissions than concrete in the life cycle. Before proposing this new basement material, the geotechnical aspect of mass timber basements should be examined. An experimental building with a CLT panel basement was completed at a cohesive soil site in Edmonton. The basement was 3 m by 6 m in plan and 2 m deep. The site profile consists of glaciolacustrine clay, with a more clayey composition at shallower depths. In-situ monitoring instrumentations were extensively used to measure the earth pressure, CLT deflection, timber strain, and soil temperature and moisture content. This paper presents the details of a field experiment development proposed to assess the soil-structure interaction of a CLT basement. Earth pressure cells show measurements of lateral earth pressure values ranging between the at-rest lateral and active earth pressure. Strains measurements are affected by the changes in the relative humidity and the wall volume change due to moisture content changes.