Abstract: The ground subsidence induced by the subway tunnel crossing the karst terrain in Wuhan City is becoming an imperative issue to be resolved in the tunnel engineering practice. This paper presents the research results of the process and mechanical features of the ground subsidence in the karst terrain under different geological conditions. The following topics have been evaluated and studied: 1): a new visualization experimental device was developed to investigate the micro-mechanics under different geological and hydrodynamic conditions. 2): Development process of the ground subsidence over karst terrain under the four typical geological structure conditions was performed based on the PFC-CFD method. 3): Utilizing the pure sand collapse model as the research object, the development of pore water pressure and porosity under different vibration frequency and amplitude was studied, and the comparative analysis was performed by laboratory experiments. 

Key words: Geological Tectonic Structure, Ground Subsidence in Karst Terrain, Pore Water Pressure, Porosity, Particle Flow Code-Computational Fluid Dynamics (PFC-CFD)