On February 18, 2025, the National Natural Science Foundation Key Project "Theory and Methods for Safety Control in Urban Underground Engineering Construction and Operation," led by Academician Chen Xiangsheng, Dean of our institute, successfully passed its concluding defense. This achievement marks another significant milestone in the advancement of fundamental theories and technological innovations in the field of urban underground space development in China.

(Academician Chen Xiangsheng presenting the project conclusion defense)

The development and utilization of urban underground space are crucial for enhancing the comprehensive carrying capacity of cities and ensuring territorial space security. However, challenges such as unclear mechanisms of construction-induced disturbances and difficulties in effectively controlling underground structural deformations persist, posing risks to the overall safety of underground spaces. Against the backdrop of integrating metro construction with the safe development of urban underground spaces, the project focused on two primary subjects: metro shield tunnels, which represent the largest and most problematic underground structures, and the emerging prefabricated underground stations. Through systematic research combining indoor model tests, full-scale experiments, numerical simulations, and theoretical analysis, the project established a unified constitutive model for saturated/unsaturated soils applicable to typical underground engineering activities and developed in-situ determination methods for key parameters. It elucidated the mechanisms of stratum disturbance in underground engineering, revealed the interaction laws between strata and underground structures under long-term temperature changes, and uncovered the performance evolution mechanisms of metro shield tunnel segments and prefabricated underground station structures. Furthermore, the project established a safety control theory and methodology for urban underground engineering based on "index identification-risk assessment-multidimensional control." Over its five-year duration, the project produced 56 high-quality papers (41 indexed in SCI), secured 14 invention patents, and registered 5 software copyrights. It also trained 4 postdoctoral researchers, 2 doctoral students, and 23 master's students, with 3 team members receiving the National Excellent Young Scientists Fund and 2 selected for the Postdoctoral Innovative Talent Support Program. The project garnered 4 provincial and ministerial-level scientific awards.

Relying on this project, Academician Chen Xiangsheng's team developed a series of innovative experimental devices, including an ultra-large full-scale test system for prefabricated underground structures. The research outcomes have strongly supported over 20 major national underground engineering projects, including the internationally pioneering double-tunnel closely spaced pipe-jacking metro station construction technology, making significant contributions to maintaining China's leading position in underground engineering research and construction technology globally.

(Full-scale test system for prefabricated underground structures independently developed)

We extend our heartfelt congratulations to Academician Chen and his team for their remarkable achievements! We look forward to more scientific research outcomes that will contribute to national urban construction and high-quality development!