Shear behavior and centrifuge seismic modeling of a sustainable corbel dwelling with interlocking blocks

Abstract

Humanity faces the challenge of addressing the growing demand for affordable and resilient housing. This paper builds on recent advances that enabled the sustainable fabrication of customized interlocking Compressed Earth Blocks (CEBs) for a sustainable dwelling in low-resource settings. Specifically, this work aims to evaluate the mechanical performance of the system through a comprehensive experimental campaign, including uniaxial compression, four-point bending, pushout shear, and friction tests. These tests characterized the material and interfacial behavior of both full-scale CEBs and scaled additively manufactured (3D-printed) physical models. Then, the seismic performance of a corbelled dome-like structure was investigated through centrifuge shake table testing at the ETH Zurich (ETHZ) Geotechnical Centrifuge Center (GCC) for a possible implementation site in Uganda. A key innovation of this work is the use of additive manufacturing to produce scaled CEB units for centrifuge-based seismic modeling. The results demonstrate that the interlocking geometry provides significant shear resistance, and the scaled models effectively replicate the mechanical behavior of full-scale systems. The additively manufactured models of the CEB blocks show similar interlocking and friction properties. The centrifuge shake table test shows that the tested model survived earthquakes stronger than the design level in Uganda. There were some minor residual deformations due to sliding between the interlocking blocks, mainly related to tolerances. However, these residual deformations would not jeopardize the structural integrity of the dwelling, thus making it resilient.