Analytical solution for 1D consolidation of unsaturated soil with mixed boundary condition

Based on consolidation equations proposed for unsaturated soil, an analytical solution for 1D consolidation of an unsaturated single-layer soil with nonhomogeneous mixed boundary condition is developed. The mixed boundary condition can be used for special applications, such as tests occur in laboratory. The analytical solution is obtained by assuming all material parameters remain constant during consolidation. In the derivation of the analytical solution, the nonhomogeneous boundary condition is first transformed into a homogeneous boundary condition. Then, the eigenfunction and eigenvalue are derived according to the consolidation equations and the new boundary condition. Finally, using the method of undetermined coefficients and the orthogonal relation of the eigenfunction, the analytical solution for the new boundary condition is obtained. The present method is applicable to various types of boundary conditions. Several numerical examples are provided to investigate the consolidation behavior of an unsaturated single-layer soil with mixed boundary condition.     

Constitutive model of saturated soft clay with cyclic loads under unconsolidated undrained condition

An equivalent visco-elastic model of saturated soft clay was studied under unconsolidated undrained (UU) condition, which can be used to evaluate the stability of ocean foundation. Cyclic triaxial compression and extension tests were conducted to study the parameters of the model. Results showed that the relationships of the damping ratio and the octahedral shear modulus with the octahedral cyclic shear strain were nearly unique, when the initial octahedral shear stress ratios of specimens were equal to 0.3, 0.5 and 0.7. The relationships of the damping ratio and the octahedral shear modulus with the octahedral cyclic shear strain determined from the cyclic triaxial compression tests were basically the same as those determined from the cyclic triaxial extension tests. Furthermore, the relationships were not related to the initial stress condition, the test stress state and the octahedral cyclic shear stress ratio. The relationships determined from the cyclic triaxial tests under no deviatoric stress were basically the same as those determined from the cyclic triaxial tests under deviatoric stress. The change of the octahedral cyclic accumulative strain with the number of cycles was unique under different tests stress states. An equivalent visco-elastic constitutive model of saturated soft clay under UU condition was initially established.     

考虑孔压梯度和应变梯度影响的饱和土剪切稳定性分析

Nomenclatureσey　effectivestressin ydirectionτ　shearstressγ　shearstrain γ　 shearStrainratiop　porepressureζ = 2 p x2 　porepressuregradientη = 2 γ x2 　straingradientρ　 densityofsaturatedsoilμ　 viscosityofwaterk　 physicalpermeabilityC1　materialparameterEr　reboundmodulusofgrainsα　frequencyofperturbationβ　 wavenumberofperturbationR0 　strainhardeningcoefficientQ0 　porepressuresofteningcoefficientH0 　strainratiohardeningcoefficientS0 　straingradientofcoefficientP0 　pore…     

Experimental study of seismic cyclic loading effects on small strain shear modulus of saturated sands

INTRODUCTION Adequate information on dynamic soil proper-ties, especially dynamic shear modulus and dampingratio, is essential for accurate computations of groundresponse and soil-structure interaction problems.Many experimental investigations carried out onsandy soils through resonant column test or improvedcyclic triaxial test in early studies (Hardin and Richart1963; Hardin and Black, 1968; Drnevich and Richart,1970; Seed and Idriss, 1971; Kokusho, 1980) showedthat the small …     

Liberal Philosophy of Education: a paradigm under strain1

This paper suggests that liberal philosophy of education, which shares the implicit commitments of modern neutralist liberalism, also exhibits that political philosophy's theoretical inadequacies and inability to guide practice. It argues that neither theoretical perspective can redeem its claims to equally respect the demands of liberty and equity, when those claims rely only on arguments of procedural value. Consequent implications, for both educational theory and educational aims, are discussed.     

Transient response of a spherical cavity with a partially sealed shell embedded in viscoelastic saturated soil

INTRODUCTION The propagation of stress-waves in an elasticmedium containing a cavity that are due to arbitrarydynamic loading applied on the cavity is of greatimportance in the fields of seismology, geophysicalprospecting, underground tunnels and deeply buriedpipelines, particularly as a model of an earthquakesource. Ben-Menahem and Cisternas (1963) devel-oped the theory for the dynamic response of an elastichalf-space medium to an explosion spherical cavity.Norwood and Miklowitz (…     

文学翻译神似的前提：语域对应——以《汤姆叔叔的小屋》的两个译本为例

语域理论是系统功能语言学的重要理论之一,它主要由语场、语旨和语式三个变项组成。从语域理论角度对比分析Uncle Tom＇s Cabin的两个中文译本。语域理论为文本分析提供了一个理论框架,有利于译者形成清晰的翻译思维,对译文选词进行合理地甑别,从而达到较理想的翻译效果。     

分散控制系统(DCS)在热电厂的应用

简述了分散控制系统(DCS)的几个特点，通过引用几个实例说明DCS控制系统以其功能齐全、高可靠性、扩展方便、组态灵活和强大通信功能的优点，目前在热电厂得到了广泛应用。并提出了工程中采用DCS时需注意的几个问题。     

Regulations: Correspondence Courses in Higher Education (1987)

Article 34. Funds for operating correspondence courses are raised from three channels: appropriations from governments at different levels that are in charge of the schools, collections from units with which the students are affiliated, and appropriate fees collected from students.     

Steady-state response of a saturated half-space with an overlying dry layer subjected to a moving load

In this paper, the steady-state response of a saturated half-space with an overlying dry layer subjected to a moving rectangular load is investigated. The governing partial differential equations are solved using the Fourier transform. The solutions in time-space domain are expressed in terms of infinite Fourier type integrals, which can be evaluated only by numerical quadrature. Numerical results show that the influence of a drained or undrained interface on the response is related to the permeability of the underlying saturated soil. Moreover, the effect due to the upper dry layer is associated with the thickness of the layer.     

一场可怕的错误：《尤利西斯》与《奥德修纪》的对应

从来没有人怀疑过《尤利西斯》与《奥德修纪》之间的对应关系其实是可笑的、荒谬的。由于与《奥德修纪》的对应关系已经成为《尤利西斯》研究的一个不变的模式,半个多世纪以来,它几乎成了评判《尤利西斯》的一个不容置疑的标准。但现代主义的批评矛头直接指向的就是传统的英雄人物和神话传说。在各种先锋运动风起云涌的时代,使用希腊神话不但是错误的,而且反动的。现代艺术的真正英雄是大众;现代传奇是漫画,而不是神话。就像乔伊斯自己所承认的,在现代文学中使用神话是一个可怕的错误,而造成这一错误的根本原因不过是为了追求小说销量的市场效应。     

FLAC3D应变软化与摩尔库伦模型工程应用对比

为探索能合理反映围岩应变软化特征的数值分析方法,设计了2组单轴数值实验,对摩尔库伦模型与应变软化模型进行对比分析,以得到不同本构条件下岩石的应力应变规律的差异;选取小官庄铁矿一段深埋巷道进行了数值模拟,分析了围岩在不同本构下的位移、塑性区的分布规律;基于FLAC3D内嵌的fish语言,编制了计算围岩点安全系数的程序,对不同本构模型下围岩的稳定性进行了评价。分析结果表明:应变软化模型得到的围岩竖向与水平位移均大于摩尔库伦模型下的对应结果,塑性区向直墙两侧与拱顶扩展更深。应变软化模型计算得到的围岩不稳定区域增大,表明巷道开挖对围岩扰动范围更大。应变软化模型的结果更接近于工程实际,更合适反映深埋工程的应力变形特性。     

成人高等函授教育质量管理的问题与对策

高等函授教育是我国发展成人高等学历教育的主干形式,在我国构建终身教育体系和全面建设小康社会中担负着重要任务。教学质量是成人高等函授教育的核心问题。本文结合自己在函授教学中的调查,简略分析了教学质量管理中存在的问题,并提出相应的对策。     

浅谈国际商务英语函电中的礼貌原则

国际商务英语函电对于当今的进出口业务起着十分重要的作用。本文主要论述了礼貌原则在商务函电中的体现与应用。     

Villainy,incompetence, and foolishness: Correspondence study in fiction

Like other professions and vocations, correspondence study has provided the inspiration and setting for works of fiction. Novelists and short story writers have used correspondence study to convey broad humour, satire, and tragedy. They have also used it for such genre writings as murder mysteries and science fiction. For the most part, fictional portrayals are negative and exaggerated, with many characters drawn from stereotypes. In spite of this, correspondence study and distance education instructors and administrators should find these portrayals of themselves and their work enjoyable, and perhaps even useful.     

3D wind-induced response analysis of a cable-membrane structure

Wind loading is a dominant factor for design of a cable-membrane structure. Three orthogonal turbulent components, including the longitudinal, lateral and vertical wind velocities, should be taken into account for the wind loads. In this study, a stochastic 3D coupling wind field model is derived by the spectral representation theory. The coherence functions of the three orthogonal turbulent components are considered in this model. Then the model is applied to generate the three correlated wind turbulent components. After that, formulae are proposed to transform the velocities into wind loads, and to introduce the modified wind pressure force. Finally, a wind-induced time-history response analysis is conducted for a 3D cable-membrane structure. Analytical results indicate that responses induced by the proposed wind load model are 10%-25% larger than those by the con- ventional uncorrelated model, and that the responses are not quite influenced by the modified wind pressure force. Therefore, we concluded that, in the time-history response analysis, the coherences of the three orthogonal turbulent components are necessary for a 3D cable-membrane structure, but the modified wind pressure force can be ignored.     

虫草头孢霉JY-1培养条件的优化

对一株具有潜在工业应用价值的菌株虫草头孢菌JY-1的液体培养条件进行了研究,以生物量为指标,对相关参数进行了优化.优化结果:最适pH为7.0;适宜接种量为8%(V/V);最大溶解氧浓度.     

芽孢杆菌B1对黄瓜枯萎病菌的拮抗作用

黄瓜枯萎病是一种严重危害黄瓜的土传性真菌病害,且防治困难.为了筛选出对黄瓜枯萎病菌防治效果较好的生物制剂,从新乡市牧野菜区蔬菜种植区黄瓜根际土壤筛选、分离经温室内消毒土壤处理选育出一株杆菌B1,通过对该菌的形态特征的观察和一系列的生理生化鉴定实验,鉴定属于芽孢杆菌.经室内平板对峙实验发现其对黄瓜枯萎病致病菌有很强的拮抗作用,抑制强度与其发酵滤液浓度呈显著正相关.苗期盆栽实验表明该生防菌株对黄瓜枯萎病菌的防效达70.10%,具有潜在的应用价值.     

商务英语函电中的文化因素初探

商务英语函电是一种在商务环境下利用函电与具有不同文化背景的客户进行交流的跨文化交际行为.文章以Hofstede 的文化维度理论和Hall 的高低语境论为理论背景,结合思维差异分析,综合探讨了函电中的文化因素,以期达到消除文化障碍,顺利利用函电进行交际的目的.