A catenary model for the analysis of arching effect in soils and its application to predicting sinkhole collapse

This paper describes a model for the prediction of sinkhole collapse for two-dimensional and axisymmetric conditions. The model explains the arching effect on the threshold of collapse by a catenary arch or dome that tries to redirect the self-weight of the unstable soil to the adjacent stable mass. The collapse mechanism considers the vertical displacement of this unstable soil mass through vertical slip planes. An adapted Krynine's construction is used for predicting Mohr-Coulomb failure conditions on the base of the catenary arches for saturated or dry conditions, whereas a simple modification is proposed for unsaturated conditions. Upward growth of sinkholes is also discussed on the basis of the model described, as well as the dependency of the stability of arches on oscillations of the water level. Some case studies and experimental evidence are presented for evaluation and application of the proposed model. It is shown that the catenary arch assumption is an efficient but simple approach for the prediction of sinkhole growth and collapse.

Automated summary

This paper presents a model for predicting sinkhole collapse under two-dimensional and axisymmetric conditions, explaining the arching effect on collapse through catenary arches or domes. The model considers vertical displacement of unstable soil mass and discusses the upward growth of sinkholes and the stability of arches in relation to water level oscillations.