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931.
We consider the free convection about a vertical flat plate embedded in a porous medium within the framework of a boundary layer approximation. In some cases, similarity solutions arise in the modelization of such phenomena, allowing a reduction of the dimension of the problem. We suggest two complementary and rather simple numerical methods to compute such solutions. When possible, the numerical analysis for the two discretizations is performed and convergence results are given. Numerical experiments with a physical model are presented to confirm the efficiency of both approaches. 相似文献
932.
933.
934.
935.
Embedded foundation in layered soil under dynamic excitations 总被引:1,自引:0,他引:1
The critical step in the substructure approach for the soil–structure interaction (SSI) problem is to determine the impedance functions (dynamic-stiffness coefficients) of the foundations. In the present study, a computational tool is developed to determine the impedance functions of foundation in layered soil medium. Cone frustums are used to model the foundation soil system. Cone frustums are developed based on wave propagation principles and force-equilibrium approach. The model is validated for its ability to represent the embedded foundation in layered medium by comparing the results with the rigorous analysis results. Various degrees of freedom, such as, horizontal, vertical and rocking are considered for this study. 相似文献
936.
Research on seismic stress triggering 总被引:6,自引:0,他引:6
Introduction What is called seismic stress triggering refers to that stress change tensor produced by previous earthquake projected on the fault plane and slip direction of subsequent earthquakes, taking into account normal stress, pore pressure and friction coefficient, and Coulomb failure stress change DCFS can be obtained. If the direction of Coulomb failure stress changes are consistent with slip direction of subsequent seismic mechanism, e.g., Coulomb failure stress changes are positive… 相似文献
937.
三重介质储渗系统与水驱油机理探讨——以塔河油田为例 总被引:8,自引:4,他引:8
探讨了塔河油田奥陶系碳酸盐岩油藏三重介质储渗系统的识别,划分和与之相对应的水驱油机理,具有高孔低渗特征的岩块系统主要靠自吸排油方式水驱油,在驱替压力和重力作用下,高孔高渗特征的洞穴系统水驱油近乎均匀推进,低孔高渗特征的裂缝系统水驱油易发生指进和突进。 相似文献
938.
通过地震活动性特征研究了华北与东南沿海地区岩石介质差异性,以唐山、海域及福建地区为例,计算了上述地区的视应力降和环境应力背景值,并用分形理论中的标度揭示了这种差异性的定量特征。结果表明,在华北地区(唐山与海城),环境应力值有强烈的涨落,而东南沿海地区(福建)其涨落并不明显,从而揭示了华北与东南沿海地区地壳岩石介质的差异性。这意味着上述地区的动力学特征在板块构造力作用下存在明显的差异。最后,应用动力学观点讨论了上述变化的复杂性和可能存在的问题。 相似文献
939.
940.
In this paper, structure models of the crust and upper mantle beneath each station have been obtained by way of fitting synthetic
seismograms with P waveforms of deep focus teleseismic records from the 11 stations in the Northeastern Region of China. We
have studied the structure in the region based on those models. Our results show that the medium of the crust and upper mantle
is a layered structure with alternate high and low velocity layers within about 100 km under the region. The crustal thickness
is about 31.8–35.8 km.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 471–479, 1991.
This work is one part of the project funded by the State Seismological Bureau of China. 相似文献