盾构法隧道开挖的三维有限元模拟

介绍有限差分法三维计算程序FLAC3D进行盾构隧道地表变形计算的建模方法和参数的选择,研究隧道不同埋深,不同盾构机推力对地表变形的影响;并进行结果分析。     

浅析土工格栅加筋边坡双斜块破裂面计算理论

土工格栅广泛地应用于各种建设工程中,针对黄土地区的路基分析,介绍了一种有别于传统的破裂面的计算方法,即双斜块计算理论.对此理论的原理进行了分析和推导,并以此计算了某个实际工程的数据,最后与FLAC软件计算结果进行对比,得到较为满意结果.     

基于ANSYS和FLAC的滑坡稳定性分析

FLAC是一个利用显式有限差分方法为岩土提供精确有效分析的工具，具有强大的计算能力及良好的二次开发性，可以解决诸多有限元难以模拟的复杂工程问题。然而，由于FLAC主要采用命令驱动模式运行，建立复杂模型的难度比较大，软件ANSYS的突出优点就是建模方便；结合两个软件的优点，本文根据工程实例，采用ANSYS建立有限元模型，将模型转入FLAC进行计算，并对计算成果进行合理的分析。     

基于FLAC3D万家口子水电站滑坡体三维模型计算分析

FLAC3D基于差分格式的三维快速拉格朗日分析程序,能很好地模拟地质材料在达到强度极限或屈服极限时发生的破坏或塑性流动的力学行为,特别适用于分析渐进破坏和失稳以及模拟大变形。根据万家口子水电站左岸滑坡体的地质特性,运用FLAC3D建立计算模型,并在自重及自重+地震荷载种天然工况下进行三维稳定分析计算,验证了计算模型的合理性,并为进一步库水位突变工况数值模拟计算提供可靠依据。     

FLAC3D在某水电站滑坡体稳定计算中的应用

以某水电站左岸滑坡体为例,运用FLAC3D建立三维模型,在水库校核洪水位工况及库水位由校核洪水位突降至设计洪水位工况下进行了分析计算,对崩滑体的变形和塑性状态做了定量分析,并得出了崩滑体稳定性评价结论。     

FLAC3D在边坡中的应用分析

FLAC3D是以拉格朗日差分法为基础的一种数值模拟软件,近几年该软件已经广泛应用于工程领域,结合不同坡度的边坡,用FLAC3D进行了稳定性分析计算。结果表明,采用FLAC3D对边坡稳定计算是可行的,而FLAC程序与其他计算方法相比,具有编程简单,便于工程技术人员掌握及现场应用,可解决大变形问题。     

回灌工程经济效益计算探讨

随着水资源供需矛盾的日益尖锐，利用汛期，非汛期的废弃水或供水效益较低的水进行回灌，作为解决水资源供需矛盾的途径之一，将会日益为人们所重视，回灌工程的经济效益，是回灌工程可行性研究的一个重要方面。本文除对回灌水量进行分析外，在回灌工程宏观经济效益计算常规方法－直接计算法介绍基础上，研究了两种简便易行的间接计算法－最优等效替代工程措施法和直接经济损失法。此外，对回灌工程的财务效益进行了简略分析，这些对     

基于HYPERMESH复杂地质体的FLAC3D实体建模

FLAC3D采用显式有限差分法求解微分方程,在土木工程领域数值分析中具有明显的优越性,但FLAC3D在复杂三维地质模型建立方面存在不足．结合AUTOCAD和HYPERMESH软件构建复杂地质模型,充分利用HYPERMESH在划分网格、提高网格质量和连续性检查等优点进行前处理．采用FORTRAN语言编写的HYPERMESH—TO—FLAC3D接口程序把建立的复杂模型导入至FLAC3D进行分析计算,从而实现用FI。AC3D解决问题时快速精准的建模目的．通过乌东德水电站地下洞室群三维建模实例检验了该方法的可行性和有效性,结果表明：基于HY—PERMESH软件建立复杂三维地质模型,并将其导入FLAC3D,结果令人满意,提高了建模效率,说明该方法在FLAC3D复杂模型建立方面具有一定的参考实用价值．     

基于SQL Server平台复杂地质体FLAC3D模型的构建

由于FLAC3D软件建立复杂三维地质体模型难度大、易出错,提出一种新的建模方法,即提取三维地质体建模数据并进行编辑成相应的表,把表导入SQL Server软件中,通过SQL查询语言生成FLAC3D可直接读取模型数据文件,从而实现在FLAC3D软件中准确、快速和自动化建立复杂三维地质模型的目的.通过云南某矿山的三维建模实例检验了该方法的可行性和高效性.结果表明:该方法在FLAC3D中建立复杂地质体模型具有一定的参考价值.     

浅埋暗挖地铁隧道施工方案FLAC优化分析

以北京地铁奥运支线奥森区间隧道工程为依托,将上下台阶法与预留核心土法作为拟采用的2种隧道开挖施工方案,运用FLAC软件对2种隧道开挖施工过程进行了模拟.根据FLAC模拟结果,确定预留核心土法作为浅埋暗挖的施工方案.运用FLAC模拟的结果预测地表变形规律.建议了超前小导管注浆和格栅钢架的联合施工方法为奥森区间隧道地表沉降变形的控制措施.工程实践表明,FLAC模拟建议的施工方案是合理可行的.FLAC计算预测的地表变形值与实测值基本一致.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that