长江口软土的压缩特性及围堤沉降预测分析

针对长江口地区软土沉降预测困难的问题,进行了一系列原状软土与重塑软土固结试验,以研究软土的固结和次固结特性.探究长江口软土的压缩指数范围、次固结系数与荷载的关系等,对长江口软土、典型上海软土及崇明岛软土工程特性进行了对比.采用两种沉降计算方法对工后沉降进行计算及预测,并分析两种方法的实用性.试验结果表明:长江口地区淤泥质粉质黏土压缩指数为0.316～0.364,淤泥质黏土为0.267～0.313,略大于典型上海软土的压缩指数;原状土次固结系数随荷载的增大,先增大后减小,重塑土次固结系数与荷载无关;长江口软土次固结系数大于典型上海软土的次固结系数.长江口软土与典型上海软土及崇明岛区域软土物理性质指标有一定差异.     

软土分析

软土是工程中常见的一类土,工程性质较为特殊,是地基工程中的重点与难点。文章以软土概况为出发点,总结软土的性质,从原理上分析软土抗剪强度,简单描述软土沉降的基本组成部分和沉降计算方法。     

砂黏复合地层盾构隧道施工地表横向沉降分析

依托广州地铁二号线洛溪—南浦区间盾构隧道工程,选取其中处于砂黏互层地层的六个监测断面对其横向沉降进行研究。选择能反映沉降槽偏移的高斯峰值函数拟合实测的沉降数据,得到沉降槽宽度系数、最大沉降量等横向沉降特征的重要参数;并对监测断面的沉降槽对称性进行分析。根据现有的沉降槽宽度系数预测理论,提出了更适合砂黏互层地层沉降槽沉降系数的计算方法;并与拟合值进行了比较。与软土地层、砂砾土地层的沉降槽宽度系数对比,结论表明在等效洞径比相近的情况下沉降槽宽度:软土地层砂黏互层地层砂砾土地层。     

砂粘复合地层盾构隧道施工地表横向沉降分析

文章依托广州地铁二号线洛溪—南浦区间盾构隧道工程,选取其中处于砂粘复合地层的六个监测断面对其横向沉降进行研究;选择能反映沉降槽偏移的高斯峰值函数拟合实测的沉降数据,得到沉降槽宽度系数、最大沉降量等横向沉降特征的重要参数,并对监测断面的沉降槽对称性进行分析;根据现有的沉降槽宽度系数预测理论,提出了更适合砂粘复合地层沉降槽沉降系数的计算方法,并与拟合值进行了比较; 与软土地层,砂砾土地层的沉降槽宽度系数对比,结论表明在等效洞泾比相近的情况下沉降槽宽度：软土地层＞砂粘复合地层＞砂砾土地层。     

深厚软土先预压后换填泡沫混凝土轻质路堤现场试验研究①

针对深厚软土路基压缩性大和工后沉降控制难的问题,以温州绕城高速公路西南线工程为依托,提出了先预压后换填泡沫混凝土施工技术,对典型断面卸载前表层累计沉降和换填泡沫混凝土后关键节点沉降进行监测,对该处理方式的加固效果进行了评估。研究表明:典型断面在卸载前表层沉降约为2m,表明深厚软土预压期沉降量大;建议下一级加载前沉降速率小于5mm/d,为了保证软土沉降;在运营半年后典型断面最大沉降为4mm,预测运营15a后累计沉降为62mm,低于设计标准值。说明采用先预压后换填泡沫混凝土的方法能有效的处理深厚软土路基,可为类似工程提供参考。     

软土工后沉降双曲线模型与指数曲线模型分析

分析软土工后沉降的典型预测模型,指出了预测误差的原因.阐明双曲线模型只是基于模型曲线与实测沉降形状相似的基础上提出的,没有理论依据;指数曲线模型主要基于太沙基一维固结理论,模型假定与工程实际有较大出入,所以两者具有较大的拟合误差.从数学角度证明了在初始沉降速率和最终沉降分别相同的情况下,指数模型预测结果大于双曲线模型的预测结果.沉降预测工程实例进一步证明了数学分析的正确性.讨论了理想工后沉降模型应具备的数学性质.     

Peck公式在砂卵石地层盾构隧道施工地表沉降预测中的应用研究

基于乌鲁木齐砂卵石地层地铁隧道现场监测数据,采用回归分析方法对典型断面地表沉降进行分析,得到适用于砂卵石地层的Peck公式,并进行了现场数据验证.研究成果表明得到的peck公式能够有效预测砂卵石地层盾构施工地表沉降,具有工程指导意义.     

大型群桩-软土共同作用性状研究

以某水闸工程为研究对象,应用有限元方法对大型群桩与软土地基共同作用性状进行了研究.建立三维非线性有限元模型,通过改变影响沉降参数和桩体布置方式、桩径、桩端土性质等,分析了群桩沉降性状.结果表明,在实际工程中,桩直径以800~1 000 mm为优,桩端部土体用于持力层的土体弹性模量不宜小于400 MPa.     

某填海工程海上通道固结变形及沉降监测分析

在分析海相软土工程性质和借鉴日本关西机场工程经验数据的基础上,基于Terzaghi一维固结理论以及二维Biot固结理论,分别进行某大型填海造地工程海上通道的一维和二维固结沉降数值模拟分析,得出海上通道沉降分析结果与规律,并与采用双频GPS和高精度水准仪相结合的方法联测出的沉降监测数据进行对比,预测海上通道最终沉降量.计算结果表明:沉降分析结果与实测数据吻合较好,预测的海上通道沉降、超静孔隙水压力发展趋势及最终沉降量可靠.     

深层承压水降水引起地层沉降的多工况数值模拟

基于上海某地铁换乘枢纽地下综合体工程背景,借助Geo Studio2007岩土工程有限元数值分析软件,针对上海地区第二层承压水降水及其引起的地层沉降进行数值模拟,考虑了两种降压井布置方式,设置了原位无基坑、单个基坑和多个基坑三种工况,并对各工况下降水后的地层沉降作了对比分析.研究表明,在对第二层承压水设定相同的水位降深时,三种工况下地表沉降值的相对大小关系随距离降压中心位置的变化而变化;基坑围护结构对于地表沉降存在隔断作用,有利于地表沉降的收敛;降压井的不同布置形式影响着三种工况的最大地表沉降值;对第二承压含水层实施降压,只会在该土层引起压缩变形,其上覆各土层的地层沉降基本相同.本文的研究成果对于软土地区多基坑遭遇深层承压水降水问题具有一定的指导价值和借鉴意义.     

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.     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.