A series of plane-strain physical model experiments are carried out to study the spatiotemporal evolution rule of rocks fracture surrounding gob-side roadway, which is subjected to the pressure induced by the mining p...A series of plane-strain physical model experiments are carried out to study the spatiotemporal evolution rule of rocks fracture surrounding gob-side roadway, which is subjected to the pressure induced by the mining process. The digital photogrammetry technology and large deformation analysis method are applied to measure the deformation and fracture of surrounding rocks. The experimental results indicate that the deformation and fracture of coal pillars are the cause to the instability and failure of the surrounding rocks. The spatiotemporal evolution rule of the rock deformation and fracture surrounding gob-side roadway is obtained. The coal pillar and the roof near coal pillar should be strengthened in support design. The engineering application results also can provide a useful guide that the combined support with wire meshes, beam, anchor bolt and cable is an effective method.展开更多
Shoemaking is one of the areas where CAD/CAM application is rapidly increasing.This paper introduces an integrated computer aided shoemaking system including human foot measuring,last (wooden model)measuring,last CAD/...Shoemaking is one of the areas where CAD/CAM application is rapidly increasing.This paper introduces an integrated computer aided shoemaking system including human foot measuring,last (wooden model)measuring,last CAD/CAM and pattern CAD/CAM.The project was supported by the 7th national economical 5 year plan.High technologies,suh as digital image processing,pattern rcognition,advanced geometrical modeling and a series of sophisticated equipments and devices are ap- plied in this integrated system.Parts of the system have become commercial products.展开更多
An advanced stability analysis of surrounding rock can assure safe construction in tunnels.However,in traditional analysis methods,geometric information on the rock mass discontinuities is obtained by a geological com...An advanced stability analysis of surrounding rock can assure safe construction in tunnels.However,in traditional analysis methods,geometric information on the rock mass discontinuities is obtained by a geological compass and treated as an infinitely expanded plane in a numerical simulation,which is inaccurate in both geometric and numerical models.To solve this problem,this paper studied a control network and an image stitch method to assess the accuracy of a geometric model and proposed a more accurate method to obtain the geometric information of rock mass discontinuities based on digital photogrammetry.Based on discrete fracture network and discrete element method(DFN-DEM),this paper treated the rock mass discontinuities obtained by digital photogrammetry as finite disk planes and simulated the excavation process of the Qianyu tunnel.According to the simulation results,this paper determined the specific location of the collapse disaster on the tunnel face,which is of great significance to tunnel support design.Comparing the deformation of the surrounding rock mass on the tunnel face in the simulation results with the actual situation,this paper verified the feasible accuracy of this method in analysing the stability of the surrounding rock mass on a tunnel face in advance.展开更多
基金supported by the National Natural Science Foundation of China (No. 51174197)the Major State Basic Research Development Program of China (No. 2014CB046905)+1 种基金State Key Laboratory for Geo Mechanics and Deep Underground Engineering (CUMT) (No. SKLGDUEK1503)the ‘Qing Lan’ Project of Jiangsu Province
文摘A series of plane-strain physical model experiments are carried out to study the spatiotemporal evolution rule of rocks fracture surrounding gob-side roadway, which is subjected to the pressure induced by the mining process. The digital photogrammetry technology and large deformation analysis method are applied to measure the deformation and fracture of surrounding rocks. The experimental results indicate that the deformation and fracture of coal pillars are the cause to the instability and failure of the surrounding rocks. The spatiotemporal evolution rule of the rock deformation and fracture surrounding gob-side roadway is obtained. The coal pillar and the roof near coal pillar should be strengthened in support design. The engineering application results also can provide a useful guide that the combined support with wire meshes, beam, anchor bolt and cable is an effective method.
文摘Shoemaking is one of the areas where CAD/CAM application is rapidly increasing.This paper introduces an integrated computer aided shoemaking system including human foot measuring,last (wooden model)measuring,last CAD/CAM and pattern CAD/CAM.The project was supported by the 7th national economical 5 year plan.High technologies,suh as digital image processing,pattern rcognition,advanced geometrical modeling and a series of sophisticated equipments and devices are ap- plied in this integrated system.Parts of the system have become commercial products.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(Grant No.52025091)the National Natural Science Foundation of China(Grant No.52109127)+2 种基金the Joint Funds of the National Natural Science Foundation of China(Grant No.U1934218)the National Natural Science Foundation of China(Grant No.52009076)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(Grant No.2021QNRC001).
文摘An advanced stability analysis of surrounding rock can assure safe construction in tunnels.However,in traditional analysis methods,geometric information on the rock mass discontinuities is obtained by a geological compass and treated as an infinitely expanded plane in a numerical simulation,which is inaccurate in both geometric and numerical models.To solve this problem,this paper studied a control network and an image stitch method to assess the accuracy of a geometric model and proposed a more accurate method to obtain the geometric information of rock mass discontinuities based on digital photogrammetry.Based on discrete fracture network and discrete element method(DFN-DEM),this paper treated the rock mass discontinuities obtained by digital photogrammetry as finite disk planes and simulated the excavation process of the Qianyu tunnel.According to the simulation results,this paper determined the specific location of the collapse disaster on the tunnel face,which is of great significance to tunnel support design.Comparing the deformation of the surrounding rock mass on the tunnel face in the simulation results with the actual situation,this paper verified the feasible accuracy of this method in analysing the stability of the surrounding rock mass on a tunnel face in advance.
