Exploring the Geomechanics of Sinkholes: A Numerical Simulation Approach: Fid-Bau Portal

Exploring the Geomechanics of Sinkholes: A Numerical Simulation Approach

Rawal, Kishor / Wang, Zhong-Mei / Hu, Liang-Bo

Sinkhole is a hazardous geological phenomenon which in recent years has occurred with an alarmingly increased frequency around the world. Although the conceptual nature of the involved key mechanisms of formation of the sinkhole is well-known and is believed to be related to the interaction between the underlying limestone rock layer and the groundwater subsequently leading to the accumulated deformation in the soil overlaying the weakened rocks, there has not been an adequate amount of geomechanical research devoted to the study of sinkholes in a quantitative manner. This paper presents some of the preliminary results of an ongoing research aimed to explore a geo-mechanical modelling approach and to understand the behavior of geo-materials around sinkholes. The finite difference program, FLAC, is used to model the behavior of geo-materials involved and simulate the deformation and stress characteristics of sinkholes. A parametric study is conducted to examine the results with different sizes of cavity, overburden thickness and pressure. The potential scenario of water drawdown is also examined. The results demonstrate some key characteristics of sinkhole subsidence and the feasibility of a geomechanical approach manifested in numerical modelling to improve the understanding of the process of sinkhole development.