This volume contains a compilation of studies regarding novel technology of underground space development, behavior analysis and modelling of soils and underground infrastructure from the 6th GeoChina International Conference held in Nanchang, China from July 19 to 21, 2021.  The scope of the studies covers both methodological and pragmatic solutions to critical issues, including soil arching and invert heaving, penetration resistance of mono-bucket foundations in silty soil, inception of debris avalanches, and novel infrastructure survey methods based on point cloud and image analysis. It is anticipated that this updated knowledge will lead to more resilient design, expedited inspection, timely maintenance and rehabilitation of underground infrastructure, and will be beneficial to both researchers and practitioners in the field.