This study aimed to address the challenges of solid waste utilization, cost reduction, and carbon reduction in the treatment of deep-dredged soil at Xuwei Port in Lianyungang city of China. Past research in this area was limited. Therefore, a curing agent made from powdered shells was used to solidify the dredged soil in situ. We employed laboratory orthogonal tests to investigate the physical and mechanical properties of the powdered shell-based curing agent. Data was collected by conducting experiments to assess the role of powdered shells in the curing process and to determine the optimal ratios of powdered shells to solidified soil for different purposes. The development of strength in solidified soil was studied in both seawater and pure water conditions. The study revealed that the strength of the solidified soil was influenced by the substitution rate of powdered shells and their interaction with cement. Higher cement content had a positive effect on strength. For high-strength solidified soil, the recommended ratio of wet soil: cement: lime: powdered shells were 100:16:4:4, while for low-strength solidified soil, the recommended ratio was 100:5.4:2.4:0.6. Seawater, under appropriate conditions, improved short-term strength by promoting the formation of expansive ettringite minerals that contributed to cementation and precipitation. These findings suggest that the combination of cement and powdered shells is synergistic, positively affecting the strength of solidified soil. The recommended ratios provide practical guidance for achieving desired strength levels while considering factors such as cost and carbon emissions. The role of seawater in enhancing short-term strength through crystal formation is noteworthy and can be advantageous for certain applications. In conclusion, this research demonstrates the potential of using a powdered shell-based curing agent for solidifying dredged soil in an environmentally friendly and cost-effective manner. The recommended ratios for different strength requirements offer valuable insights for practical applications in the field of soil treatment, contributing to sustainable and efficient solutions for soil management.

China has built the world's largest high-speed railway (HSR) network, which has fueled regional economic growth. Mounting photovoltaics (PV) on the roofs of HSR station houses and platforms can potentially provide electricity for high-speed trains, change the energy mix, and reduce emissions. Therefore, it is crucial to assess the technical potential and economic environmental performance of PV for the HSR infrastructure. In this study, the PV potential of 973 stations of 108 HSR lines in China was studied in conjunction with geographic infor-mation system (GIS). The results showed that the PV capacity that can be deployed in China's HSR stations at horizontal and optimum tilt angles was 4.36 GW and 2.81 GW, with a total power generation capacity of 108.55 TWh and 74.88 TWh, respectively, which presented a huge power generation potential. The economic analysis showed that the All-consumption scenario and optimum tilt angle had better economic profits than the All-feed-into-grid scenario and the horizontal angle, respectively. Moreover, the use of PV could reduce carbon emissions by HSR stations by 79,895.73 kilotons and 55,112.53 kilotons at horizontal and optimum tilt angles, respec-tively. The study revealed that the combination of PV and HSR infrastructure was a good strategy for sustainable transportation and carbon neutrality goals.