Seismic design of a low-carbon building constructed with in-situ produced compressed earth blocks

Abstract

The seismic design of buildings erected using new low-carbon construction materials needs the development of a reliable methodology. In this research, a pilot project of a compressed earth block (CEB) masonry building in a medium-high seismic hazard zone in Southern France is developed. The CEBs are produced in-situ, using a machine, and are used as construction material for low-rise masonry buildings. This innovative low-carbon construction technology permits the reuse of local soil, removed during earthworks, with consequent reduction of energy consumption related to its collection, transport, recovery, and disposal. Even if the CEB masonry building is a promising low-carbon construction, its structural performance assessment, especially in seismic zones, is a challenging issue.

Starting from the experimental characterization of material mechanical parameters, the seismic design approach focuses on the modal characteristics of the structure, the expected building ductility, and seismic performance assessment in terms of both displacement and force. The behavior factor for a CEB masonry building is an original result of this research. The equivalent frame model adopted for structural design of load-bearing masonry is validated, after the building construction, by comparing the dynamic properties obtained by both numerical and operational modal analysis. Moreover, the modal analysis highlights the impact of the timber slab stiffness on the dynamic response of masonry buildings and suggests that a careful timber slab conception improves the structural behavior under seismic loading.