Study on the uniaxial compression constitutive relationship of modified yellow mud from minority dwelling in western Sichuan, China

Abstract More than 2 billion people around the world still use raw earth architecture, in countries like Nepal, India, and Iran. In China, the proportion of people living in earthen structures rose to 36%, some of them in western Sichuan. Minority dwellings in western Sichuan, China, use local stone and yellow mud as building materials and have been used for thousands of years. Because yellow mud is a brittle material with poor mechanical properties, and because the region is prone to earthquakes, the walls are highly susceptible to damage under seismic action. To improve the mechanical properties of yellow mud, the yellow mud of Taoping Qiang Village in western Sichuan was studied and modified. Uniaxial compressive tests were conducted on the modified specimens, and the existing ontogenetic equations of raw soil-based materials were analyzed and optimized. Finally, we developed the constitutive models for yellow clay and modified yellow clay in the western Sichuan area, which can be used for different kinds of modified materials through the variation of parameters. The results show that the compressive strength of yellow clay is improved by adding the modified materials. The optimized constitutive model can better fit the test curves, which can provide a basis for theoretical calculations and seismic mitigation of minority residential structures in western Sichuan or similar structural systems.