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61.
A numerically efficient and stable method is developed to analyze Biot's consolidation of multilayered soils subjected to non‐axisymmetric loading in arbitrary depth. By the application of a Laplace–Hankel transform and a Fourier expansion, the governing equations are solved analytically. Then, the analytical layer‐element (i.e. a symmetric stiffness matrix) describing the relationship between generalized displacements and stresses of a layer is exactly derived in the transformed domain. Considering the continuity conditions between adjacent layers, the global stiffness matrix of multilayered soils is obtained by assembling the inter‐related layer‐elements. Once the solution in the Laplace–Hankel transformed domain that satisfies the boundary conditions has been obtained, the actual solution can be derived by the inversion of the Laplace–Hankel transform. Finally, numerical examples are presented to verify the theory and to study the influence of the layered soil properties and time history on the consolidation behavior. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
62.
在大连新港油罐区的建设中,发现了一种具有高孔隙性、高含水量、高塑性、中低压缩性的特殊土。作者对这种土及其母岩的矿物学、岩石学、地球化学、物理化学和工程特性进行了系统研究,揭示了该区红粘土及其工程特性的形成机理,该区红粘土乃是蒙脱石化的粗玄岩,在中温带气候区红土花作用的产物。  相似文献   
63.
Field and chemical data show that soils in some parts of Bauchi State, Nigeria, are rich in illite (20–35%), montmorillonite (60–75%), and kaolinite (45–73%). These expansive clays cause the soils to shrink and swell alternatively in response to the seasonal supply of moisture; resulting in observed damaging cracks. Plasticity index (PI) determinations on these soils are high (7–13.4%) suggesting that they are potentially hazardous. The attendant hazards and huge losses to the State are blamed on the expansive nature of these soils. The hazardous conditions can be mitigated by adopting proper construction precautions as well as by using chemical additives such as lime and phosphates, to lower the PI and help to increase the strength of the soils.  相似文献   
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Summary In many parts of the world, particularly in humid tropical regions, residual soils are abundant. In this paper the suitability of a residual lateritic soil as a construction material is investigated, with respect to its strength and compaction characteristics. In comparison with other typical construction fills available in Southeast Asia, compacted lateritic soils produce excellent shear strengths and CBR values. However, the brittleness and tensile cracking of this compacted material become enhanced on the dry side of the optimum moisture content, or if excessive compaction is imparted. Nevertheless, at a moisture content of 2% wetter than the optimum, the tensile mode of failure is suppressed and the lateritic fills become ideally suited for the construction of high embankments and impervious dam cores.  相似文献   
67.
SOIL SHEAR STRENGTH: AN INDICATOR FOR ERODIBILITY OF THE LOESS SOILS   总被引:1,自引:0,他引:1  
SOILSHEARSTRENGTH:ANINDICATORFORERODIBILITYOFTHELOESSSOILSWANGGuiping;WEIZhongpingandZHANGZhiguoAbstract:FieldexperimentSunde...  相似文献   
68.
Soil hydrophobic effects on infiltration and catchment runoff   总被引:1,自引:0,他引:1  
After dry summers or drought, eucalypt forest soils at two sites in southeastern Australia developed hydrophobic or non-wetting surface characteristics that reduced infiltration, measured using a sprinkling infiltrometer. At one site the development of hydrophobic conditions caused the rainfall to runoff conversion efficiency of a forested catchment to increase from 5 per cent to 15 per cent. Under non-hydrophobic conditions at this site, grassland always generated more runoff than forest. However, one major rainfall-runoff was recorded at a time of highly hydrophobic forest soil conditions and this storm generated greater runoff on the forested catchment than the grassland catchment. At the second site forest soils have naturally highly conductive surface layers because of a dense network of macropores and pathways for preferential flow. Hydrophobic conditions produced by drought caused soil water movement to be confined to only a few of the larger macropores exposed to surface ponded water. Even so, infiltration rates remained relatively high so that the impacts of hydrophobic soils were not translated into increased catchment runoff as at the first site.  相似文献   
69.
The stable growth condition of a segregated ice layer is studied by the use of the principle of mass and heat conservation. This condition evidently depends upon the properties of a thin transitional zone, which is believed to exist between the boundary of an ice layer and a 0[°C] isotherm. All probable models of the transitional zone are classified and the conditions for each model is derived. The effect of the small amount of soil minerals contained in an ice layer is also studied.  相似文献   
70.
Two types of clayey soils, a kaolinite and a bentonite, were tested using a resonant column apparatus under random excitation conditions. The concept of root mean square (rms) strain was utilized for the purpose of strain calculations during random loading. The conventional estimator of the transfer function was used for random vibration analysis. The effect of confinement duration (at a constant pressure) on dynamic soil properties, namely damping and shear modulus, was evaluated. The results indicate that for both cohesive soils, the effect of time was less pronounced during random vibration than sinusoidal loading at the same rms strain. This effect is however more pronounced when the peak shearing strain of sinusoidal loading is considered. Furthermore, time effects were more pronounced at low strain levels than at high strain levels.  相似文献   
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