Numerical simulation of karst environments to study subsidence

Abstract

Karstic zones, due to dissolution of limestone rocks, are a problem in several areas of the world, being associated with damage sustained by facilities, among other issues. A numerical study is presented using Plaxis 2D to analyse terrain subsidence on the surface, considering a transversal section to apply a road load, while cavities in the ground increase due to karsticity. Results allow perception of the surface subsidence, associated with the number of cavities, before and up to collapse of the first voids created. Stress paths developed in the cavities’ opening process are built from the interpretation of results provided by the numerical analyses. These stress paths make it possible to obtain the way in which stress values change between initial and final states, defining an in situ stress variation for the void's presence. Furthermore, it is concluded that there is a tendency towards stability for the superficial displacement and a maximal affected horizontal length associated with a specific number of cavities, despite the fact that more of these are developed in the zone. The rocks and the soil were simulated by Hoek–Brown and Mohr–Coulomb constitutive models, considering the specific characteristics of rocks and soil endemic to Yucatan, Mexico.