Microseismic effects during the transmission of seismic waves in coal and rock mass associated with mining operation were studied by on-site blasting tests and microseismic monitoring in LW704 of Southern Colliery,Aus...Microseismic effects during the transmission of seismic waves in coal and rock mass associated with mining operation were studied by on-site blasting tests and microseismic monitoring in LW704 of Southern Colliery,Australia,by using spread velocities,amplitudes and frequency contents as the main analysis parameters.The results show that the average P-wave velocity,mean values of combined maximal amplitudes and frequencies of the first arrivals are all reduced significantly along with goaf expanding and intensity weakening of overlying strata during mining process.A full roof fracturing can make the average P-wave velocities,combined maximal amplitudes and frequencies of first arrivals reduce to about 69.8%,92.2% and 60.0%,respectively.The reduction of the above seismic parameters reveals dynamic effects of the variation of strata structure and property to the wave transmission and energy dissipation of blasting wave.The research greatly benefits further study on stability of surrounding rock under the destructive effort by mine tremor,blasting,etc,and provides experimental basis for source relocation and parameter optimization of seismic monitoring as well.展开更多
This article is concerned with the numerical detection of bifurcation points of nonlinear partial differential equations as some parameter of interest is varied.In particular,we study in detail the numerical approxima...This article is concerned with the numerical detection of bifurcation points of nonlinear partial differential equations as some parameter of interest is varied.In particular,we study in detail the numerical approximation of the Bratu problem,based on exploiting the symmetric version of the interior penalty discontinuous Galerkin finite element method.A framework for a posteriori control of the discretization error in the computed critical parameter value is developed based upon the application of the dual weighted residual(DWR)approach.Numerical experiments are presented to highlight the practical performance of the proposed a posteriori error estimator.展开更多
基金Foundation item: Project(2010CB226805) supported by the National Basic Research Program of ChinaProject(2010QNA30) supported by the Fundamental Research Funds for the Central Universities of China+1 种基金Project supported by the Priority Academic Development Program of Jiangsu Higher Education,ChinaProjects(SZBF2011-6-B35,2012BAK04B06) supported by the National Twelfth Five-year Key Science & Technology Foundation of China
文摘Microseismic effects during the transmission of seismic waves in coal and rock mass associated with mining operation were studied by on-site blasting tests and microseismic monitoring in LW704 of Southern Colliery,Australia,by using spread velocities,amplitudes and frequency contents as the main analysis parameters.The results show that the average P-wave velocity,mean values of combined maximal amplitudes and frequencies of the first arrivals are all reduced significantly along with goaf expanding and intensity weakening of overlying strata during mining process.A full roof fracturing can make the average P-wave velocities,combined maximal amplitudes and frequencies of first arrivals reduce to about 69.8%,92.2% and 60.0%,respectively.The reduction of the above seismic parameters reveals dynamic effects of the variation of strata structure and property to the wave transmission and energy dissipation of blasting wave.The research greatly benefits further study on stability of surrounding rock under the destructive effort by mine tremor,blasting,etc,and provides experimental basis for source relocation and parameter optimization of seismic monitoring as well.
基金the financial support of the EPSRC under the grant EP/E013724the support of the EPSRC under the grant EP/F01340X.
文摘This article is concerned with the numerical detection of bifurcation points of nonlinear partial differential equations as some parameter of interest is varied.In particular,we study in detail the numerical approximation of the Bratu problem,based on exploiting the symmetric version of the interior penalty discontinuous Galerkin finite element method.A framework for a posteriori control of the discretization error in the computed critical parameter value is developed based upon the application of the dual weighted residual(DWR)approach.Numerical experiments are presented to highlight the practical performance of the proposed a posteriori error estimator.
