There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground engineering.The previously proposed four‐dimensional support(here...There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground engineering.The previously proposed four‐dimensional support(hereinafter 4D support),as a new support technology,can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure,and prevent instability of surrounding rock in underground engineering.However,the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still unknown.This study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy development.The elastic strain energy was analyzed using the program redeveloped in FLAC3D.The numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 m.With the increase of roadway depth,4D support can effectively restrain the area and depth of plastic deformation in the surrounding rock.Further,4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases.4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 months.As confirmed by in situ monitoring results,4D support is more effective for the long‐term stability control of surrounding rock than conventional support.展开更多
Based on the measured displacements,the change laws of the effect of distance in phase space on the deformation of mine lane were analyzed and the chaotic time series model to predict the surrounding rocks deformation...Based on the measured displacements,the change laws of the effect of distance in phase space on the deformation of mine lane were analyzed and the chaotic time series model to predict the surrounding rocks deformation of deep mine lane in soft rock by nonlinear theory and methods was established.The chaotic attractor dimension(D) and the largest Lyapunov index(Emax) were put forward to determine whether the deformation process of mine lane is chaotic and the degree of chaos.The analysis of examples indicates that when D>2 and Emax>0,the surrounding rock's deformation of deep mine lane in soft rock is the chaotic process and the laws of the deformation can still be well demonstrated by the method of the reconstructive state space.Comparing with the prediction of linear time series and grey prediction,the chaotic time series prediction has higher accuracy and the prediction results can provide theoretical basis for reasonable support of mine lane in soft rock.The time of the second support in Maluping Mine of Guizhou,China,is determined to arrange at about 40 d after the initial support according to the prediction results.展开更多
A similar material model and a numerical simulation were constructed and are described herein.The deformation and failure of surrounding rock of broken and soft roadway are studied by using these models.The deformatio...A similar material model and a numerical simulation were constructed and are described herein.The deformation and failure of surrounding rock of broken and soft roadway are studied by using these models.The deformation of the roof and floor,the relative deformation of the two sides and the deformation of the deep surrounding rock are predicted using the model.Measurements in a working mine are compared to the results of the models.The results show that the surrounding rock shows clear rheological features under high stress conditions.Deformation is unequally distributed across the whole section.The surrounding rock exhibited three deformation stages:displacement caused by stress concentration,rheological displacement after the digging effects had stabilized and displacement caused by supporting pressure of the roadway.Floor heave was serious,accounting for 65% of the total deformation of the roof and floor.Floor heave is the main reason for failure of the surrounding rock.The reasons for deformation of the surrounding rock are discussed based on the similar material and numerical simulations.展开更多
In light of the severe deformation and destruction of the district raise tunnel in the mining area at the northern part of the Lubanshan colliery, by the theoretic analysis and numerical simulation, both the mining st...In light of the severe deformation and destruction of the district raise tunnel in the mining area at the northern part of the Lubanshan colliery, by the theoretic analysis and numerical simulation, both the mining stress distribution in seams group and the deformation and destruction mechanism of floor district raise were investigated. The results show that, at the maximum vertical distance of 40 m, the abutment stress has an influence on the recovery of 2# and 3# coal seam and 8# coal seam at distance of 30 m. As a result, the recovery of 8# is rather than those of 2# or 3# coal seam, which contributes to the deformation and destruction of the district raise surrounding rock. The major factors affecting the abutment stress include the mining depth, mining height, residual gob space, adjacent working faces and short spacing coal seam recovery.展开更多
基金support from the National Key Research and Development Program of China(Nos.2023YFC2907300 and 2019YFE0118500)the National Natural Science Foundation of China(Nos.U22A20598 and 52104107)the Natural Science Foundation of Jiangsu Province(No.BK20200634).
文摘There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground engineering.The previously proposed four‐dimensional support(hereinafter 4D support),as a new support technology,can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure,and prevent instability of surrounding rock in underground engineering.However,the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still unknown.This study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy development.The elastic strain energy was analyzed using the program redeveloped in FLAC3D.The numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 m.With the increase of roadway depth,4D support can effectively restrain the area and depth of plastic deformation in the surrounding rock.Further,4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases.4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 months.As confirmed by in situ monitoring results,4D support is more effective for the long‐term stability control of surrounding rock than conventional support.
基金Project（2017RCJJ011） supported by the Scientific Research Foundation of Shaaadong University of Science and Technology for Recruited Talents, China Projects（01CK03203, 02CK02302） supported by the Shaaadong Provincial First-Class Discipline Fundamental, China Proj ect（ZR2018QEE001） supported by the Natural Science Foundation of Shandong Province, China
基金Project(50490274) supported by the National Natural Science Foundation of China
文摘Based on the measured displacements,the change laws of the effect of distance in phase space on the deformation of mine lane were analyzed and the chaotic time series model to predict the surrounding rocks deformation of deep mine lane in soft rock by nonlinear theory and methods was established.The chaotic attractor dimension(D) and the largest Lyapunov index(Emax) were put forward to determine whether the deformation process of mine lane is chaotic and the degree of chaos.The analysis of examples indicates that when D>2 and Emax>0,the surrounding rock's deformation of deep mine lane in soft rock is the chaotic process and the laws of the deformation can still be well demonstrated by the method of the reconstructive state space.Comparing with the prediction of linear time series and grey prediction,the chaotic time series prediction has higher accuracy and the prediction results can provide theoretical basis for reasonable support of mine lane in soft rock.The time of the second support in Maluping Mine of Guizhou,China,is determined to arrange at about 40 d after the initial support according to the prediction results.
基金Project 40773040 supported by the National Basic Research Program of China
文摘A similar material model and a numerical simulation were constructed and are described herein.The deformation and failure of surrounding rock of broken and soft roadway are studied by using these models.The deformation of the roof and floor,the relative deformation of the two sides and the deformation of the deep surrounding rock are predicted using the model.Measurements in a working mine are compared to the results of the models.The results show that the surrounding rock shows clear rheological features under high stress conditions.Deformation is unequally distributed across the whole section.The surrounding rock exhibited three deformation stages:displacement caused by stress concentration,rheological displacement after the digging effects had stabilized and displacement caused by supporting pressure of the roadway.Floor heave was serious,accounting for 65% of the total deformation of the roof and floor.Floor heave is the main reason for failure of the surrounding rock.The reasons for deformation of the surrounding rock are discussed based on the similar material and numerical simulations.
基金Project(51104176)supported by the National Natural Science Foundation of China
文摘In light of the severe deformation and destruction of the district raise tunnel in the mining area at the northern part of the Lubanshan colliery, by the theoretic analysis and numerical simulation, both the mining stress distribution in seams group and the deformation and destruction mechanism of floor district raise were investigated. The results show that, at the maximum vertical distance of 40 m, the abutment stress has an influence on the recovery of 2# and 3# coal seam and 8# coal seam at distance of 30 m. As a result, the recovery of 8# is rather than those of 2# or 3# coal seam, which contributes to the deformation and destruction of the district raise surrounding rock. The major factors affecting the abutment stress include the mining depth, mining height, residual gob space, adjacent working faces and short spacing coal seam recovery.
