Abstract: In order to meet the high stability requirements of highprecision and highly sensitive cuttingedge physics laboratory operating environment, by taking the Moganshan mine tunnel renovation and expansion project as an example, the feasibility of the design scheme for the renovation and expansion of existing mines into kilometer level underground laboratories is studied based on the advantages of low cost, short construction period, strong stability, and basic completeness of functions of existing mines. The design concept of "adapting to local conditions, highlighting characteristics, limited renovation, synchronous construction, and space reservation" is proposed, highdensity electrical methods, geological radar methods, and other comprehensive methods are used to deduce goaf data, and a highly reliable design system for the renovation and expansion of existing mines into underground laboratories is established. The research results indicate that: (1) By fully utilizing the spatial conditions of the existing mine tunnels in both horizontal and vertical directions, the functions of the mine tunnels on south sides can be reasonably positioned, and expansion conditions can be reserved; (2) Adopting two forms of reconstruction and expansion, i.e., insitu single side and double side, the design difficulties of section selection can be solved; (3) Adopting the treatment plan of upper grouting reinforcement and lower comprehensive, the goaf treatment problem is easy to be solved; (4) The use of early fire prediction and other control measures can effectively reduce the frequency and losses of fires.

Key words: mine tunnel renovation and expansion, underground laboratory, section selection, goaf management, tunnel fire protection design