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1.
This paper proposes a multi‐level parallelized substructuring–frontal combined algorithm for the analysis of the problem of thermo/hydraulic/mechanical behaviour of unsaturated soil. Temperature, displacement, pore water pressure and pore air pressure are treated as the primary variables in a non‐linear analysis. Details are given firstly of the substructuring–frontal combined approach. The incorporation of the algorithm in a multi‐level parallel strategy is then discussed. The parallel processing can thus be carried out at different substructural levels. The method thus developed impacts, in a positive way, on both computer storage requirement and execution time. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
2.
By using small scale model tests, the interference effect on the vertical load-deformation behavior of a number of equally
spaced strip footings, placed on the surface of dry sand, was investigated. At any stage, all the footings were assumed to
(i) carry exactly equal magnitude of load, and (ii) settle to the same extent. No tilt of the footing was permitted. The effect
of clear spacing (s) among footings on the results was explored. A new experimental setup was proposed in which only one footing
needs to be employed rather than a number of footings. The bearing capacity increases continuously with decrease in spacing
among the footings. The interference effect becomes further prominent with increase in soil friction angle. In contrast to
an increase in the bearing capacity, with decrease in spacing of footings, an increase in the footing settlement associated
with the ultimate state of shear failure was observed. The present experimental observations were similar to those predicted
by the available theory, based on the method of characteristics. As compared to the theory, the present experimental data,
however, indicates much greater effect of interference especially for larger spacing among footings. 相似文献
3.
饱和软黏土动力学特性循环扭剪试验研究 总被引:2,自引:0,他引:2
以饱和软黏土的循环扭剪试验研究为基础,阐明不固结不排水条件下饱和软黏土的动力学特性。在循环扭剪和循环三轴两种不同试验应力状态下,通过研究不同围压和不同静、动应力组合下饱和软黏土的应力等效破坏关系和应变等效破坏关系,提出在循环荷载作用下饱和软黏土的循环破坏同样遵循Mises屈服准则,且在Mises屈服准则下,饱和软黏土的循环强度趋于不变量。循环破坏的过程可以等效为一种拟静力弹塑性循环蠕变,建立了饱和软黏土循环累积变形随静荷载、循环荷载以及循环破坏振次之间的关系式。上述结论分别从应力和变形两个方面阐述饱和软黏土的动力学特性,与试验应力状态和围压无关,可以推广到一般应力状态下。 相似文献
4.
Low-frequency damping of a moored semisubmersible drilling platform was obtained from numerical extinction tests simulated in still water and in regular waves and from mean wave drift forces calculated at zero forward speed. The influence of drag forces was represented by the modified Morison equation. The platform as used for the 18th ITTC Comparative Mooring Study was analyzed in irregular beam waves. The computed time series of sway as well as the corresponding sway response spectrum compared favourably with model test measurements, demonstrating that this procedure to determine low-frequency damping can be effective. 相似文献
5.
Profiles observed by Sea-Wing underwater gliders are widely applied in scientific research. However, the quality control(QC) of these data has received little attention. The mismatch between the temperature probe and conductivity cell response times generates erroneous salinities, especially across a strong thermocline. A sensor drift may occur owing to biofouling and biocide leakage into the conductivity cell when a glider has operated for several months. It is therefore critical to design a mature real-time QC procedure and develop a toolbox for the QC of Sea-Wing glider data. On the basis of temperature and salinity profiles observed by several Sea-Wing gliders each installed with a Sea-Bird Glider Payload CTD sensor, a real-time QC method including a thermal lag correction, Argo-equivalent real-time QC tests, and a simple post-processing procedure is proposed. The method can also be adopted for Petrel gliders. 相似文献
6.
对类比路段进行连续模拟试验,进行现场调查,给出汽车尾气主要污染物的排污强度,预测了汽车尾气中CO、C_nH_m和NO_x的扩散范围。 相似文献
7.
A fairing method is presented for giving a good representation of ship model resistance test data, which in general tend to exhibit a scattered trend and need to be smoothed appropriately. One component of the test data originates from the frictional resistance and can be formulated smoothly. The second component is the wave resistance which exhibits a specific harmonic character with peaks and troughs. In this method, this component is modelled using suitable harmonic cosine terms for obtaining the best representation of the corresponding resistance data. The performance of the method is then tested on two example cases, using the characteristic parameters of the sample data as input during the smoothing process. 相似文献
8.
In 1995, Suh and Park developed a numerical model that computes the reflection of regular waves from a fully perforated-wall caisson breakwater. This paper describes how to apply this model to a partially perforated-wall caisson and irregular waves. To examine the performance of the model, existing experimental data are used for regular waves, while a laboratory experiment is conducted in this study for irregular waves. The numerical model based on a linear wave theory tends to over-predict the reflection coefficient of regular waves as the wave nonlinearity increases, but such an over-prediction is not observed in the case of irregular waves. For both regular and irregular waves, the numerical model slightly over- and under-predicts the reflection coefficients at larger and smaller values, respectively, because the model neglects the evanescent waves near the breakwater. 相似文献
9.
10.
Mechanism for the rapid motion of the Qianjiangping landslide during reactivation by the first impoundment of the Three Gorges Dam reservoir, China 总被引:10,自引:6,他引:4
Fawu Wang Yeming Zhang Zhitao Huo Xuanming Peng Shimei Wang Shintaro Yamasaki 《Landslides》2008,5(4):379-386
The first impoundment of the Three Gorges Dam reservoir in China started from a water surface elevation of 95 m on June 1,
2003 and reached 135 m on June 15, 2003. Shortly after the water level reached 135 m, many slopes began to deform and some
landslides occurred. The Qianjiangping landslide is the largest one; it occurred on the early morning of July 14, 2003 and
caused great loss of lives and property. Field investigation revealed that, although failure occurred after the reservoir
reached 135 m, the stability of the slope was already reduced by preexisting sheared bedding planes. To study the mechanism
of the rapid motion of this reactivated landslide, two soil samples were taken from a yellow clay layer and a black silt layer
in the sliding zone, respectively, and a series of ring shear tests were conducted on the samples. One series of ring shear
tests simulates the creep deformation behavior, while the other series simulates different shear rates. Conclusions drawn
from analysis of the ring shear tests indicate that the mechanism of the rapid motion of the reactivated landslide was caused
by the rate effect of the black silt layer during the motion phase after the creep failure. The yellow clay layer did not
play any important role in the rapid motion in the 2003 event. 相似文献