Stress-strain Analysis of the Remediation Works Implemented to Stabilize the Mining Subsidence Under the La Inmaculada School, Zaruma-Ecuador

This work establishes 4 stress-deformational scenarios that show the instability process and remediation works, in relation to the subsidence event and collapse of the land where the school La Inmaculada (Zaruma-Ecuador) was established. Longitudinal profiles were used in the direction of the exploitation of the "Tres Reyes" vein where the geological-structural model that serves as a basis for the calculation of the deformations in the mining galleries around their plastic behavior is shown. For the modeling, it was necessary to determine, the dead load of the infrastructure, pseudo-static loads, positioning of the water table, physical-mechanical-elastic parameters of the rock matrix and discontinuities that together define the behavior of stress and deformation by means of the numerical technique of Finite Element Method (FEM). Design an optimized mortar with a dosage of 1 cement (C): 2 tailings (R) and a water (A)/cement (C) ratio of 0.49 to obtain a strength of 18 MPa after 14 days of curing. Finally, it is proved that the application of the backfill with tailings mortar inside the galleries near the collapse zone, substantially decreases the deformation of the rock substrate from 1.9 m (Scenario 2: Empty cone) to 0.05 m (Scenario 4: Backfill with tailings mortar).