Stability Evaluation of Old Goaf Treated with Grouting Under Building Load

In this paper, stability of overlying strata and grouting entities are determined as the two key factors affecting the stability of old goaf treated with grouting under building load by theoretical analysis, the additional stress influence depth and the grouting entities strength are determined as the two key indexes for the stability of old goaf treated with grouting under building load. Through theoretical analysis and field investigation, the calculation method of the influence depth of the additional stress in the old goaf under the building load is revised, and the calculation formula of the grouting entities strength is confirmed by theoretical analysis and the experimental results. The uniaxial compression and uniaxial creep stability of the grouting entities under dry and saturated conditions are verified by mechanical experiments. And the revised parameter reference value is provided for the calculation formula of the grouting entities strength. Finally, the stability of the grouting reinforcement project in China is verified by numerical simulation.