Tai'an city, located in Shandong Province, China, is rich in geothermal resources, characterized by shallow burial, high water temperature, and abundant water supply, making them high value for exploitation. However, corrosion and scaling are main challenges that hinder the widespread application and effective utilization of geothermal energy. This study focuses on the typical geothermal fields in Tai'an, employing qualitative evaluations of the geochemical saturation index with temperature, combined with the corrosion coefficient, Ryznar index, boiler scale, and hard scale assessment, to predict corrosion and scaling trends in the geothermal water of the study area. The results show that the hydrochemical types of geothermal water in the study area are predominantly Na-Ca-SO₄ and Ca-Na-SO₄-HCO₃, with the water being weakly alkaline. Simulations of saturation index changes with temperature reveal that calcium carbonate scaling is dominant scaling type in the area, with no evidence of calcium sulfate scaling. In the Daiyue Qiaogou geothermal field, the water exhibited corrosive bubble water properties, moderate calcium carbonate scaling, and abundant boiler scaling. Feicheng Anjiazhuang geothermal field showed non-corrosive bubble water, moderate calcium carbonate scaling, and significant boiler scaling. The Daidao'an geothermal field presented corrosive semi-bubble water, moderate calcium carbonate scaling, and abundant boiler scaling. The findings provide a foundation for the efficient exploitation of geothermal resources in the region. Implementing anti-corrosion and scale prevention measures can significantly enhance the utilization of geothermal energy.

This study presents a comprehensively analysis of geothermal characteristics in the Xianshuihe geothermal area along the Sichuan-Tibet Railway, using temperature logging, temperature monitoring and thermal conductivity measurement, and regional geothermal geological survey data. The research focuses on the geothermal background, geothermal field, and their potential impact on the surrounding tunnels. The investigation reveals that the average heat flow value in the study area is approximately 73.0 mW/m², significantly higher than the average terrestrial heat flow in mainland China (​​62.5 mW/m²). This high terrestrial heat flow signifies a distinct thermal background in the area. In addition, geothermal anomalies in the area are found to be closely associated with the distribution of hot springs along NW faults, indicating a strong control by the Xianshuihe fault zone. The study concludes that the region's favorable conditions for geothermal resources are attributed to the combination of high terrestrial heatflow background and water-conducting faults. However, these conditions also pose a potential threat of heat damage to the tunnels along the Sichuan-Tibet Railway. To evaluate the risk, the research takes into account the terrestrial heat flow, thermal conductivity of the tunnel surrounding rocks, characteristics of the regional constant temperature layer, as well as the distribution of hot springs and faults. The analysis specifically focuses on the thermal damage risk of Kangding 1^# tunnel and 2^# tunnel passing through the study area. Based on the findings, it is determined that Kangding 1^# tunnel and 2^# tunnel have relatively low risk of heat damage, as they have avoided most of the high temperature anomaly areas. However, several sections of the tunnels do traverse zones with low to medium temperatures, where surface rock temperatures can reach up to 45°C. Therefore, these regions should not be neglected during the construction and operation of the tunnel project, and mitigation measures may be necessary to address the potential heat-related challenges in the area.