Soil testing and numerical modelling of a subsidence event

This work forms a portion of an ongoing research project at the University of Tennessee, Knoxville. The project involves the effects of mining induced subsidence on surface structures. In particular, this work concerns the selection and validation of an appropriate soil constitutive relation for use in a computer-based study of subsidence damage mitigation techniques. Appropriate laboratory testing was accomplished to classify the project soil, and to determine the constitutive model parameters. Several commonly used soil constitutive relations or models were reviewed. An elastoplastic model was determined to best represent the soil behavior. Material parameters were determined for the Drucker-Prager, Cam-Clay, and cap models. The Cam-Clay and cap model best represented the actual soil behavior based on the laboratory testing. A finite element (FE) analysis of a free field subsidence event was then accomplished using the Cam-Clay model. The results of the FE analysis were then compared to field data. The Cam-Clay model predicted the measured field strains satisfactorily. Therefore, the Cam-Clay model was recommended for future use in the analysis of structural damage mitigation techniques and subsidence soil-structure interaction problems.