Evaluation theory and application of foundation stability of new buildings over an old goaf using longwall mining technology

To evaluate the long-term stability of rock strata above an old goaf and its possible impact on buildings above the rock strata, releasable space in strata is analyzed and a method to calculate this releasable space, based on the characteristics of pore distribution in the rock strata above the goaf, is proposed. Releasable space in rock strata is classified into two forms: slow release space under natural conditions and sudden release space under external force. In addition, methods to evaluate the stability of a building foundation above a goaf in the two mentioned cases are presented and applied to engineering practice. The construction of a project proves the effectiveness of the evaluation method proposed in this paper.