Experimental study on the mechanical properties of polyvinyl alcohol (PVA) improved flow-sliding loess

Improving the seismic flow-sliding loess and modifying its mechanical properties are of great significance for engineering site seismic fortification and regional post-disaster reconstruction. This study investigates the improvement effect of polyvinyl alcohol (PVA) on flow-sliding loess via resonant column and direct shear tests. The variation laws of soil strength indexes and dynamic characteristics under different confining pressures and PVA contents are revealed, along with the improvement mechanism of PVA. Results show that 3% PVA content exerts the most significant influence: the cohesion of loess increases by 77%, and the specimen exhibits the largest dynamic shear modulus and the smallest damping ratio compared with 1% and 4% PVA contents. The dynamic properties of improved soil differ remarkably from the original soil. This research provides important engineering application value for disaster prevention and mitigation and urban development in loess areas.