Experimental study on impregnation and consolidation effects of modified polyvinyl alcohol solution for coarse-grained soils: a case study on the Subashi Buddhist Temple Ruins of China

The Subashi Buddhist Temple Ruins, which contain a lot of coarse-grained soils, have been severely damaged by surface weathering. Modified polyvinyl alcohol (SH) which can improve the mechanical properties of fine-grained earthen ruins has never been reported in the protection of coarse-grained earthen ruins, and thus, it is of great practical significance to investigate the impregnation and consolidation effects of SH solution on coarse-grained soils. First, the characteristic changes obtained by SH impregnation with respect to consolidation radius, impregnation rate, impregnation time, and cumulative impregnation were analysed for soil specimens with different dry densities and grain gradations. Then, disintegration, drying–wetting cycle, and freeze–thaw cycle experiments were carried out, and the results of these experiments were analysed. Finally, the impregnation and consolidation effects of the SH solution were evaluated together. The feasibility of protecting the Subashi Buddhist Temple Ruins with SH by impregnation was studied, and it is suggested that the methods of surface spraying and borehole impregnation for anti-weathering should be combined to protect these ruins.