Analytical solution for stress and deformation of the mining floor based on integral transform  

作　　者：Feng Qiang Jiang Binsong 

机构地区：[1]State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining & Technology [2]Civil Engineering and Architecture, Shandong Key Laboratory of Civil Engineering Disaster Prevention & Mitigation, Shandong University of Science and Technology

出　　处：《International Journal of Mining Science and Technology》2015年第4期581-586,共6页矿业科学技术学报（英文版）

基　　金：the National Basic Research Program of China(No.2014CB046300);the National Natural Science Foundation of China(No.51174196)

摘　　要：Following exploitation of a coal seam, the final stress field is the sum of in situ stress field and an excavation stress field. Based on this feature, we firstly established a mechanics analytical model of the mining floor strata. Then the study applied Fourier integral transform to solve a biharmonic equation,obtaining the analytical solution of the stress and displacement of the mining floor. Additionally, this investigation used the Mohr–Coulomb yield criterion to determine the plastic failure depth of the floor strata. The calculation process showed that the plastic failure depth of the floor and floor heave are related to the mining width, burial depth and physical–mechanical properties. The results from an example show that the curve of the plastic failure depth of the mining floor is characterized by a funnel shape and the maximum failure depth generates in the middle of mining floor; and that the maximum and minimum principal stresses change distinctly in the shallow layer and tend to a fixed value with an increase in depth. Based on the displacement results, the maximum floor heave appears in the middle of the stope and its value is 0.107 m. This will provide a basis for floor control. Lastly, we have verified the analytical results using FLAC3 Dto simulate floor excavation and find that there is some deviation between the two results, but their overall tendency is consistent which illustrates that the analysis method can well solve the stress and displacement of the floor.Following exploitation of a coal seam, the final stress field is the sum of in situ stress field and an exca- vation stress field. Based on this feature, we firstly established a mechanics analytical model of the min- ing floor strata. Then the study applied Fourier integral transform to solve a biharmonic equation, obtaining the analytical solution of the stress and displacement of the mining floor. Additionally, this investigation used the Mohr-Coulomb yield criterion to determine the plastic failure depth of the floor strata. The calculation process showed that the plastic failure depth of the floor and floor heave are related to the mining width, burial depth and physical-mechanical properties. The results from an exam- ple show that the curve of the plastic failure depth of the mining floor is characterized by a funnel shape and the maximum failure depth generates in the middle of mining floor; and that the maximum and min- imum principal stresses change distinctly in the shallow layer and tend to a fixed value with an increase in depth. Based on the displacement results, the maximum floor heave appears in the middle of the stope and its value is 0.107 m. This will provide a basis for floor control. Lastly, we have verified the analytical results using FLAC3D to simulate floor excavation and find that there is some deviation between the two results, but their overall tendency is consistent which illustrates that the analysis method can well solve the stress and displacement of the floor.

关 键 词：Integral transform Mining floor Plastic failure depth Floor heave Analytical solution 

分 类 号：TD311[矿业工程—矿井建设]