Keiichi Fujita lecture -- Keynote lectures -- Design, analysis, and construction of tunnels and underground space in soft ground -- Excavation and tunnelling in difficult ground conditions -- Physical and numerical modelling of deep excavation and tunnel -- Interaction between underground construction and adjacent structures -- Monitoring of underground construction -- Risk management and mitigation -- Sustainable development of underground space and its application -- Climate change and environmental-friendly underground development -- Mechanized tunnelling in soft ground.