Water-holding Properties and Electrochemical Characterization of the Soil under the Grand Deliverance Hall of the Chongshan Temple, Taiyuan City, China: Providing the Basis for Preventing Groundwater Erosion in Historic Buildings

Many historic buildings are at serious risk of deterioration due to changes in the moisture content of the soil under the buildings. Based on the typical deterioration problems of the Grand Deliverance Hall and the cultural relics in the hall, this study analyzes and concludes that the main factor affecting the generation and development of deterioration is groundwater erosion through environmental monitoring and geotechnical engineering investigation. The impact of changes in moisture content on the water-holding properties and pore distribution of the soil under the cultural-relics buildings was further assessed. Then, combined with the soil property, our study provides a novel and effective way to monitor and reflect the water-holding properties of the soil using electrochemical detection. The connected pore resistance and matrix suction decrease with the increase in the moisture content, both showing a power function law. Changes in moisture content cause changes in the thickness of the double electric layer, which in turn affects the connected pore resistance and matrix suction of soil. The greater the connected pore resistance, the greater the matrix suction and the water holding capacity. Finally, based on the research of this study and the conservation ideology of cultural relics that respects the original and minimizes intervention, protection recommendations to prevent groundwater erosion are proposed in order to provide guidance for future research.