P-wave and S-wave velocities were obtained from seismic refraction survey in the foundation layer of Eket, the study area. The Tezcan’s approach discussed extensively in the work was used in conjunction with the exis...P-wave and S-wave velocities were obtained from seismic refraction survey in the foundation layer of Eket, the study area. The Tezcan’s approach discussed extensively in the work was used in conjunction with the existing mathematical relations between elastic parameters and seismic refraction velocities for the study of foundation layers in the study area. Based on the results, the elastic constants, allowable bearing pressure/capacity, ultimate bearing capacity and other parameters in Table 1 were determined. The result shows that allowable bearing pressure increases with increase in shear modulus and shear wave velocity. The empirical relation between allowable bearing capacity and shear modulus shows that the allowable bearing capacity increases with depth. Comparing our findings with some ranges of safe allowable bearing capacities of similar non cohesive/granular soils in literatures, the second layer with allowable bearing capacity range of 72.56 - 206.63 kN·m-2?(average = 154.78 kN·m-2) has been considered to be the safe shallow engineering foundation in the study area. The empirical relations between allowable bearing capacities shear modulus and shear wave velocity, in conjunction with the inferred maps, which serve as our findings, will be used as guide in the location of foundations. The inferred ultimate and allowable capacities correlate maximally for the two shallow foundations penetrated by the seismic waves. This perfect correlation reflects the uniqueness of the method.展开更多
The observations of in-situ spacecraft mission in the magnetosheath and a region of thermalized subsonic plasma behind the bow shock reveal a non-linear behaviour of plasma waves. The study of waves and optics in Phys...The observations of in-situ spacecraft mission in the magnetosheath and a region of thermalized subsonic plasma behind the bow shock reveal a non-linear behaviour of plasma waves. The study of waves and optics in Physics has given the understanding of the effect of many waves coming together to form a wave field or wave packet. The common aspect of such study shows that two or more waves can superimpose constructively or destructively. The sudden high magnetic field data in the magnetosheath displays such possibility of superposition of waves. In this paper, we use the empirical mode decomposition (EMD) and Hilbert transform (HT) techniques to determine the instantaneous frequencies of low frequency plasma waves in the magnetosheath. Our analysis has shown that the turbulent behavior of magnetic field in the magnetosheath within the selected period is due to superposition of waves.展开更多
文摘P-wave and S-wave velocities were obtained from seismic refraction survey in the foundation layer of Eket, the study area. The Tezcan’s approach discussed extensively in the work was used in conjunction with the existing mathematical relations between elastic parameters and seismic refraction velocities for the study of foundation layers in the study area. Based on the results, the elastic constants, allowable bearing pressure/capacity, ultimate bearing capacity and other parameters in Table 1 were determined. The result shows that allowable bearing pressure increases with increase in shear modulus and shear wave velocity. The empirical relation between allowable bearing capacity and shear modulus shows that the allowable bearing capacity increases with depth. Comparing our findings with some ranges of safe allowable bearing capacities of similar non cohesive/granular soils in literatures, the second layer with allowable bearing capacity range of 72.56 - 206.63 kN·m-2?(average = 154.78 kN·m-2) has been considered to be the safe shallow engineering foundation in the study area. The empirical relations between allowable bearing capacities shear modulus and shear wave velocity, in conjunction with the inferred maps, which serve as our findings, will be used as guide in the location of foundations. The inferred ultimate and allowable capacities correlate maximally for the two shallow foundations penetrated by the seismic waves. This perfect correlation reflects the uniqueness of the method.
文摘The observations of in-situ spacecraft mission in the magnetosheath and a region of thermalized subsonic plasma behind the bow shock reveal a non-linear behaviour of plasma waves. The study of waves and optics in Physics has given the understanding of the effect of many waves coming together to form a wave field or wave packet. The common aspect of such study shows that two or more waves can superimpose constructively or destructively. The sudden high magnetic field data in the magnetosheath displays such possibility of superposition of waves. In this paper, we use the empirical mode decomposition (EMD) and Hilbert transform (HT) techniques to determine the instantaneous frequencies of low frequency plasma waves in the magnetosheath. Our analysis has shown that the turbulent behavior of magnetic field in the magnetosheath within the selected period is due to superposition of waves.
