Efficiency of periphery trench for reducing the impact of surface subsidence on structures using 1g physical modelling

Abstract : Underground mines induce a surface subsidence. The existing structures and infrastructures can be damaged by the strain and settlement of the soil in the subsided zone. Mitigation methods exist for reducing the impact of the subsidence on the existing structures. One of them is the periphery trench, the method consists in cutting the soil around the existing building then filling the trench with a compressible material. The effect of horizontal strain will be absorbed by the partial closure of the trench. Physical modelling (1g) tests were carried out to evaluate the optimal dimensions and to determine the characteristics of the filling materials that can be recommended. Thanks to results the effectiveness of the trench was confirmed; operational recommendations were made.