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61.
G. L. Sivakumar Babu Satyanarayana Murthy Dasaka 《Geotechnical and Geological Engineering》2008,26(1):37-46
The effect of directional behaviour of correlation structure of cone tip resistance on the bearing capacity of shallow strip
footing resting on cohesionless soil deposit in 2-D random field is analysed using probabilistic approach. The results obtained
from the analysis show that the assumption of perfect (or infinite) correlation of cone tip resistance data leads to lower
values of probability of failure. In contrast, the isotropic assumption of correlation behaviour based on vertical scale of
fluctuation leads to higher values of probability of failure. The results also show that the transformation model would play
a major role in the evaluation of variability of design property. In conclusion, the need for a proper evaluation methodology
for calculation of correlation lengths of soil properties and their influence in foundation design is highlighted. 相似文献
62.
Summary From the space distribution of P- and S-wave velocities, determined at a hydrostatic pressure of 1 GPa, complete sets of elastic constants were calculated for the Twin Sisters dunite. It was found that orthorhombic symmetry is a reasonable approximation for the dunite sample; with one exception the deviations of the individual constants, determined from different waves, do not exceed a few percent. As a seismological application a simple model of a 120 km thick lithosphere, formed by the dunite, was considered for calculating the differences in the time arrivals of SV and SH waves. The greatest time differences, about 3s, were obtained in the vertical plane containing the direction of the greatest P-wave velocity, however, for the real lithosphere we estimate effects which only cause differences of the order of 1s. 相似文献
63.
Ocean Dynamics - Westward propagation and the dynamics of intensification of Lakshadweep low (LL) have been investigated in detail. In this study, it is observed that LL is not propagated westwards... 相似文献
64.
A methodology for reliability based optimum design of reinforced soil structures subjected to horizontal and vertical sinusoidal excitation based on pseudo-dynamic approach is presented. The tensile strength of reinforcement required to maintain the stability is computed using logarithmic spiral failure mechanism. The backfill soil properties, geometric and strength properties of reinforcement are treated as random variables. Effects of parameters like soil friction angle, horizontal and vertical seismic accelerations, shear and primary wave velocities, amplification factors for seismic acceleration on the component and system probability of failures in relation to tension and pullout capacities of reinforcement have been discussed. In order to evaluate the validity of the present formulation, static and seismic reinforcement force coefficients computed by the present method are compared with those given by other authors. The importance of the shear wave velocity in the estimation of the reliability of the structure is highlighted. The Ditlevsen's bounds of system probability of failure are also computed by taking into account the correlations between three failure modes, which is evaluated using the direction cosines of the tangent planes at the most probable points of failure. 相似文献
65.
66.
Vladislav Babuška Jiří Fiala Mineo Kumazawa Ichiro Ohno Yoshio Sumino 《Physics of the Earth and Planetary Interiors》1978,16(2):157-176
The elastic constants of sixteen garnet specimens of wide variety in chemical composition are accurately determined by means of the rectangular parallelpiped resonance method. The dependence of the elastic properties on chemical composition is analyzed using the present data and those for seven garnets investigated by other authors. The property Xi of a garnet solid solution i is given by a linear addition law in terms of the mole fraction nij of component j; Xi = ΣnijXj where the Xj's are the properties of the end-members j (j = pyrope, almandine, spessartine, grossular and andradite). The Xj's are determined for density ρ, bulk modulus K, and shear moduli Cs = (C11 ? C12)/2 and C44. No systematic deviation is observed from the linear addition law for the elastic moduli nor for other quantities such as the elastic wave velocities. The extrapolated elastic moduli (Mbar) of the end-members are:
Almandine | Pyrope | Spessartine | Grossular | Andradite | |
1.779 ± 0.008 | 1.730 ± 0.009 | 1.742 ± 0.009 | 1.691 ± 0.008 | 1.379 ± 0.017 | |
0.981 ± 0.004 | 0.925 ± 0.004 | 0.964 ± 0.004 | 1.106 ± 0.004 | 0.979 ± 0.007 | |
0.958 ± 0.005 | 0.919 ± 0.005 | 0.937 ± 0.005 | 1.017 ± 0.006 | 0.827 ± 0.010 |