A case study investigation-based experimental research on transport of moisture and salinity in semi-exposed relics

Semi-exposed relics within an air–soil system often have earthworks partially buried, leading to moisture migration and substantial salt accumulation. Salt accumulation threatens relic preservation, but destructive sampling is hindered by conservation concerns. We conducted a case study on salt enrichment at K9901 Armour Pit of Emperor Qinshihuang 's Mausoleum Site Museum. Environmental factors and soil salt characteristics were assessed through sampling and monitoring. A relic-soil coupling system was established with a soil column device containing burned bricks. Using 5-TE sensors, water and salinity movement was tracked, and X-ray diffraction analyzed relic salt crystals. The soil column experiment effectively simulated water-salt migration in relics. Salts, like Cl⁻, NO₃⁻, SO₄²⁻, Na⁺, and Mg²⁺, concentrated on the soil surface during evaporation. Simulation linked specific salt species to relic ailments. Salt solution from soil migrated to bricks, forming CaSO₄ crystals. Results highlight coupling's role in salt-related deterioration and the need to protect it for optimal relic preservation. Findings impact semi-exposed relic conservation, revealing salt accumulation processes and their impact on historical artifacts.