正断层错动下地铁盾构隧道变形破坏模型试验研究

为揭示跨隐伏断层地铁盾构隧道结构变形破坏特征,采用自主设计的模拟隐伏断层错动加载试验装置,开展1∶25几何比例的跨断层盾构隧道模型试验,分析正断层错动下盾构隧道的力学响应规律及变形破坏特征.试验结果表明：在2 cm正断层错动影响下,隧道纵向差异变形呈现非线性增大趋势,环缝接头张开变形主要位于断层下盘隧道拱顶及断层上盘隧道拱底,且环缝峰值张开量已超过盾构隧道接缝防水限值;断层延长线与隧道交界处管片直径收敛变形较为严重,该处管片呈现拱腰外侧受拉、拱顶及拱底外侧受压的受力状态;管片与地层之间接触压力受断层错动的影响较大,存在围岩挤压区与围岩松散区,但接触压力峰值相对较小;盾构隧道的主要变形破坏特征为环缝接头拉裂破损、管片纵向开裂及环缝接头变形,管片发生斜向剪切破坏及局部压溃破坏的概率较低.基于盾构隧道环纵向变形破坏特征,建议将管片环缝变形及接头混凝土拉裂破损作为界定跨断层盾构隧道结构破坏的主要控制指标.基于隧道的变形破坏模式,提出了跨断层盾构隧道结构设计及应对措施的建议.     

逆断层错动作用下地铁隧道结构损伤分析

以乌鲁木齐地铁隧道穿越西山活动逆断层工程为例,建立三维弹塑性有限元模型.首先模拟分析了逆断层错动作用下隧道二次衬砌塑性应变发展过程,拉压损伤因子、剪切应变的横向及纵向分布规律,计算了混凝土的裂缝宽度;其次研究了不同错动位移、隧道底部距围岩交界面不同垂直距离及不同破碎带宽度的结构损伤规律,最后进行了设置柔性接头的减灾效果研究.结果表明:二次衬砌结构破坏首先出现在拱顶;然后是拱底,最后在拱腰处累积.破裂面附近拱腰处发生拉压剪的共同破坏;远离破裂面上盘拱顶,破碎带拱底处发生受拉破坏;远离破裂面上盘拱底,破碎带拱顶处发生受压破坏.基于混凝土裂缝得到隧道拉裂破坏的严重与轻微受损区分别为10 m和30 m.错动位移越大,结构受损越严重;隧道底部距围岩交界面垂直距离越大,土层越厚,耗散能量越多,结构受损越轻;破碎带宽度越大,隧道破坏越严重,当破碎带宽度达到26 m时,破碎带宽度对隧道的影响基本保持稳定.设置柔性接头可以显著降低结构的损伤,基本满足在设防错动位移下的设计要求.     

45°倾角正断层粘滑错动对隧道影响试验分析

通过1∶50室内模型试验,模拟了45°倾角正断层粘滑错动下,与之正交的隧道结构的受力变形破坏过程,并布置传感器监测了隧道顶部和底部的围岩压力、隧道轴向的应变和隧道环向的应变.结果表明,围岩压力在剪切带附近发生显著变化,上盘和剪切带范围内拱顶压力显著增大,下盘拱顶压力次之,上盘和剪切带隧道底部压力减小,下盘底部压力显著增大,隧道与下部围岩可能局部脱空以适应断层的剪切位移;上盘和剪切带范围内隧道纵向弯矩为正,下盘范围内为负,隧道偏心受压;以原型混凝土压坏来判定衬砌破坏,初步确定原型结构破坏所容许的最大断层位移D=0.7m,理论上该值略偏大;隧道衬砌破坏区域长度,在剪切带和下盘范围分别为1.7和2.8倍隧道宽度.     

地面超载条件下覆跨比对浅埋隧道稳定性的影响

以青岛地铁江西路站为工程背景,通过典型数值模型的计算与分析,研究了地面超载环境中覆跨比对浅埋隧道的变形与受力特征等开挖稳定性规律.结果表明:不同覆跨比下浅埋隧道的破坏形态相似,首先是拱肩部位的围岩发生剪切破坏,然后破坏面逐渐发展至地表,围岩的塑性区形状呈倒锥体;覆跨比大小对隧道的围岩稳定性影响显著,覆跨比小于0.2时,围岩的破坏程度严重,出现地表、拱顶沉降变形不收敛的现象;覆跨比增大,有利于加强围岩与支护的共同作用,可以控制地层的变形发展、降低围岩的应力扰动;地面超载值越高,隧道结构的变形与地表沉降越大,围岩的应力扰动也越严重.     

强降雨影响下破碎复理岩地层隧道洞口段失稳机理

针对强降雨下Kosman隧道冒顶事故,在现场实时监测基础上,结合离散元数值模拟,分析强降雨下围岩裂隙及渗流的动态变化规律。同时,用能量的方法对围岩破坏过程进行研究,分析围岩势能与动能转化过程,从能量的角度验证围岩不同区域的稳定性。研究结果表明:隧道开挖初期,围岩自承能力较好;降雨过程中,随着隧道顶部岩体节理渗流逐渐增大,岩石节理面刚度和强度逐步降低,地表至拱脚围岩扰动区出现大量剪切破坏裂缝,且数量及长度都随埋深增大而减少。贯通裂缝形成渗流通道导致降雨从拱顶处涌入洞内,洞周孔隙水压力及渗流场呈漏斗型并逐渐降低,围岩应力增大加剧沉降推动冒顶产生。     

不同覆跨比下浅埋软弱隧道的破坏模式

为了研究不同覆跨比条件下浅埋软弱隧道围岩的破坏模式,通过室内模型试验对隧道围岩破坏的过程进行模拟;利用强度折减法原理对模型试验进行有限差分数值验证,得出了二者基本一致的结论;通过对模型试验与数值模拟结果的分析,推导基于岩柱理论的修正算法。研究结果表明:浅埋软弱隧道围岩的破坏最早从拱顶开始,由于拱顶塌落区的形成,拱顶两边产生类似滑坡的塌落效应,即浅埋破碎围岩隧道的"二阶段"破坏;当覆跨比较小时,围岩的自承能力弱,围岩塌落速度快,塌落体积少,形成塌穿型塌方;当覆跨比为3.0时,形成了浅埋压力拱,破坏已不能到达地表;当覆跨比为2.5时,围岩塌落形成的塌落体体积及破裂区影响区域最大,施工时支护应及时,保证其安全。     

十房高速通省隧道变形破坏原因分析

十房高速通省隧道围岩是具有一定倾角片理面的武当群片岩,在隧道施工过程中左洞ZK114+473桩号附近左拱腰部位出现钢拱腰压断现象。针对这一现象,在大量工程地质资料和现场调查的基础上,结合室内实验结果,综合分析了其变形破坏机理;并利用通用离散元程序UDEC进行隧道开挖后的力学特性和变形特性分析,得出在片岩岩性、片理面倾角和隧道偏压效应共同作用下在拱腰处产生的拉应力是隧道拱腰部位容易产生变形破坏的主要原因,对隧道的开挖和支护具有一定的指导意义。     

层状岩体隧道围岩稳定性的数值模拟分析

层状围岩中隧道开挖会引起非对称大变形现象,导致钢拱架扭曲、二衬开裂等工程问题。针对该问题,以四川省道219线改建工程海子山隧道为工程背景,在对该隧道围岩形变规律调研的基础上,建立基于块体离散元理论的数值模型,对层状围岩地层隧道稳定性进行数值分析。研究结果表明:隧道围岩大变形主要发生在以板岩为主的软弱岩层中,围岩的变形受层理面影响,表现出显著的非对称形变特征;当层理面与掌子面交线的视倾角等于0°时,层理面倾向角对围岩位移场及其破坏形态无影响。围岩侧压力系数λ=1、λ>1以及λ<1时,围岩的破坏形态分别受层理面、主应力方向、层理面与主应力方向共同控制;当视倾角等于90°时,围岩形变特征及其破坏形态在不同层理面倾向角的影响下存在4种模式。当视倾角不等于上述特殊情况时,在不同层面倾向角的影响下,围岩的变形特征及破坏形态存在8种模式。     

浅埋隧道拱顶土石混合体围岩沉降预测

由于地层风化、水土流失等原因,隧道围岩极易形成风化土层,对浅埋隧道开挖沉降产生严重影响.利用连续-非连续数值模拟方法,对这类土石混合体围岩的拱顶沉降因素进行具体研究.结果表明:在相同工况下随着岩石含量、岩石最小粒径和最大粒径的增大,拱顶沉降量逐渐降低;随着土和岩石参数的下降,拱顶沉降量明显增加,进而得出拱顶沉降值的范围...     

浅埋暗挖隧道施工中纵向地表下沉的规律

在浅埋暗挖隧道施工中,地表沉降和拱顶下沉的信息可明显反馈围岩和初期支护的稳定状态,要实现信息化施工和控制施工中产生不利环境影响,必须了解和掌握地表沉降和拱顶下沉的变化趋势.基于南京地铁2号线钟灵街马群段浅埋暗挖隧道矿山法施工中地表沉降和拱顶下沉的实测资料,分析总结了相应条件下隧道施工中地表和拱顶下沉的大小和分布规律,得出浅埋暗挖隧道沿纵向开挖时对工作面前后的主要影响范围,分别为1.5D和3D(D为隧道跨度),变化趋势为缓慢下沉快速下沉收敛稳定;并根据滞后的拱顶下沉与地表下沉趋势的一致性,提出可以通过施工中纵向地表沉降的规律预测拱顶下沉的发展趋势.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-