基于FLAC3D的岩体初始高水平构造应力场反演方法

为探讨深部岩体工程初始高水平构造应力场的数值模拟反演方法,采用三维有限差分法FLAC~(3D)分别对位移边界条件、应力边界条件、混合边界条件及基于初始应变能理论的反演方法进行数值试验对比分析。结果表明:在模拟岩体初始高水平构造应力场过程中,位移边界条件、应力边界条件、混合边界条件三种方法均不能满足要求;而基于初始应变能理论的反演方法效果较好,将该方法应用于狮子山矿区地应力场的反演分析,计算表明各测点的地应力反演值与实测值之间误差在允许范围内,进一步验证了该方法模拟计算岩体初始高水平构造应力场具有较好的可靠性,研究成果为深部岩体工程高水平构造应力场的反演计算方法提供了参考。     

硬质围岩铁路隧道初始地应力数值反演分析

在宝(鸡)-兰(州)复线东巨寺沟硬岩铁路隧道拱顶位移和位移收敛测试数据的基础上,采用有限元法对该隧道围岩的构造应力进行数值反演,利用地应力反演结果对隧道围岩稳定性进行了分析和评价.采用反演的地应力分析结果表明,拱顶下沉、水平位移收敛值与实测值接近,支护结构围岩处于稳定状态.     

隧道围岩特性参数反分析与数值模拟

为确定合理的隧道围岩应力场和参数,采用位移反分析法进行分析.结合现场监测数据和FLAC3D有限元软件进行反演分析和围岩变形数值模拟.研究结果表明:运用FLAC3D仿真模拟开挖,隧道拱顶是危险点,开挖之后拱顶上部围岩下沉值较大;通过现场实际监测拱顶点的位移分析可知,当从第六天之后围岩趋于稳定下沉值22 mm,回归分析确定了拱顶下沉值随时间的变化指数曲线关系;根据位移反分析确定围岩弹性模量为2.5 GPa适合该工程条件,围岩其他参数也可按照该方法进行确定.     

锦屏一级水电站地下厂区非线性地应力场反演

以锦屏一级水电站地下厂区现场工程为依托,提出一种新的地应力场反演方法.该方法考虑了大型结构面对地应力场的影响特征,将含有大型结构面的工程地质模型分区进行处理.首先,在线弹性的状态下,确定边界位移的搜索范围.继而,建立初始应力场拟合优化问题的目标函数,并采用一阶优化算法,有效的避免了繁琐的运算.最后,拟合结果表明精度较好,满足了工程的需要,从而证实了提出的地应力场反演方法的可适用性与正确性.     

基于进化神经元算法的堡镇隧道软弱围岩施工弹塑性智能位移反分析

结合宜万铁路堡镇隧道的施工,将BP神经网络和遗传算法引入特长隧道软岩段的施工位移反分析,采用遗传算法自动搜索BP神经网络训练效果最优的参数,建立起反映围岩变形与岩体物理力学参数及初始地应力之间高度非线性、不确定的GA-BP智能模型,然后采用遗传算法在岩体物理力学参数和初始地应力取值范围内,搜索BP神经网络预测围岩变形与实测围岩变形最接近的参数组合,取得反演获得的岩体物理力学参数和初始地应力.从堡镇隧道应用结果来看,这种进化神经元算法反演结果可以满足隧道施工的需要,并为类似工程提供了借鉴.     

不同地应力下TBM盘形滚刀破岩特性

根据Mohr-Coulomb准则分析岩石强度与地应力的变化关系,对不同地应力下盘形滚刀破岩载荷模型进行修正;以锦屏二级水电站TBM掘进现场实测的数据为依据,建立有初始地应力和无初始地应力下盘形滚刀破岩仿真模型,并进行无初始应力滚刀破岩试验,研究盘形滚刀破岩载荷特性及岩石破碎特征。研究结果表明:随着地应力的增大,三向力载荷增大;在各个贯入度下,初始应力为28~36 MPa时与0 MPa时相比,垂直力和滚动力的增加幅度较大,增大幅度可达到70%以上,侧向力增加幅度最小;随着初始地应力的增加,滚刀总破岩量减少,破岩能耗上升;三向力理论计算值与仿真值吻合较好,相对误差范围在10%~21%之间;无初始应力下的破岩试验在一定程度上验证力学模型和仿真结果的正确性。     

基于地应力实测值的断层构造区域地应力场有限元回归反演分析

结合四川省长河坝水电站地下厂房硐室工程,考虑地形、地貌与断层等地质构造,建立了三维有限元模型,基于实测地应力值,采用多元线性回归分析方法对地应力场进行反演,以分析地下厂房区的地应力分布情况.结果表明：地下厂房硐室岩体地应力的实测值与有限元法所得反演值吻合较好,回归分析方法适用于对地应力场的反演;工程区域的水平地应力大于竖向地应力,并且地应力量值随着垂直埋深与水平埋深的增加而增大;断层附近的地应力出现了局部应力集中现象,须引起注意.     

散体围岩力学参数位移反演优化

针对散体围岩非连续性、松散的特性以及难以获得可信度高的力学参数的问题,基于Hoek-Brown强度准则和位移反演理论,提出一种新的岩体力学参数确定方法。采用Hoek-Brown强度准则估算散体围岩强度参数(黏聚力c、内摩擦角φ和抗拉强度στ)和变形参数(弹性模量EH),将估算出的强度作为位移反演分析过程中的已知参数,基于数值计算方法,对变形参数(弹性模量反算值EB和泊松比μ)进行反演优化。将弹性模量估算值EH和弹性模量反算值EB对比分析,进而修正估算的输入参数,从而得到接近实际的岩体力学参数。研究结果表明:EH与EB相差仅为0.01 MPa,相对误差为1.75%,小于5.00%,即参数合理有效;将新方法确定的力学参数应用于数值模型进行反演正算,得到ZK34+232断面拱顶下沉值和水平收敛值的相对误差分别为1.3%和3.4%,符合检验标准,满足工程实践,说明新方法是可行的,可以用于隧道工程设计和施工。     

桑珠岭特长隧道初始地应力场反演分析

桑珠岭隧道是拉萨-林芝铁路的控制性工程,工程区地质条件复杂,面临着深埋隧道高地应力灾害问题。因此,对其展开初始地应力场分析为保障隧道安全施工及优化结构设计具有重要意义。以现场勘察工作为基础,综合分析工程区地质资料,利用工程类比法和Anderson理论估算了隧址区主应力方向与量值范围;结合现场地应力实测数据,利用多元线性回归分析方法,进行了隧道工程区地应力场的三维反演计算分析。结果表明:测点地应力反演值与实测值在量值与方向上存在较好拟合关系;且同区域构造背景相一致,说明计算结果具有一定的合理性与可靠性。最后,通过分析桑珠岭隧道沿轴向的地应力分布规律,对隧道沿线的易发岩爆段及岩爆等级进行了初步预测,为后期隧道开挖及支护结构设计提供依据。     

地下厂房试验洞的粘弹性反分析

结合某地下厂房试验洞量测资料的分析,研究成层各向异性岩体中洞室工程粘弹性问题的反分析方法。反分析计算时采用分层均质模型,将计算区域内各层岩层分别视为均质各向同性体,初始地应力假设成线性分布。有限元分析中,对倾斜成层的岩层、软弱夹层及断层节理等分别划分了单元,以模拟成层岩体的分布特征及其对洞室工程在受力与变形方面所产生的一些各向异性宏观效应。为使计算过程简化,对离洞室较远的地层按地质资料对材料特性参数赋值,通过弹性反分析计算出地层初始地应力;采用三元件模型,建立围岩粘弹性反分析模型,反演求得试验洞相邻围岩的粘弹性参数值。为工程设计与支护提供了可靠的依据。     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the