Environmental changes cause the surface evapotranspiration rate of naturally preserved sandstone to vary

resulting in capillary water migration within a specific range. This process not only induces repeated hydration expansion and drying shrinkage of minerals within the sandstone but also accelerates rock deterioration due to capillary migration

including salt crystallization

dissolution cycles

freeze-thaw effects

and biological weathering. To provide a reliable reference for the preservation of historical stone buildings

this study investigates the capillary water migration mechanism

focusing on the stone archway of “Jingnanxiongzhen” in Enshi

Hubei Province. Long-term microenvironment monitoring and laboratory experiments were conducted. Numerical simulations using Comsol Multiphysics software integrated microenvironment monitoring data with rock weathering patterns

establishing a research framework under partial continuous immersion conditions. The results show that: 1) From the perspective of liquid volume fraction distribution at different times

in the long time dimension

the hydraulic gradient near the wetting front is gentle

and the volume water content of sandstone changes most sharply

and the deterioration phenomenon of rock is most obvious in this height range. 2) Once capillary water reaches dynamic equilibrium

vertical water content varies

with higher values at the bottom and lower at the top. Horizontally

water content decreases from the center to the sides. The wetting front fluctuates with evapotranspiration rate changes

aligning with observed weathering patterns. 3) Reducing the pressure head at the base of historical stone structures significantly decreases water infiltration. Lowering groundwater levels around the stone archway achieves this reduction

mitigating capillary-induced deterioration.