考虑锯齿状节理的桩岩界面模型试验研究

针对嵌岩灌注桩嵌入软弱岩层的工况,考虑成桩过程中桩岩界面的剪胀效应,采用常法向刚度边界条件(CNS)模拟软岩对桩身的侧向变形约束,开展了模拟桩岩界面侧阻力发挥的室内大尺寸直剪模型试验.将桩-岩接触面的粗糙体简化为规则的三角形锯齿,根据不同的半波长分别制作了砂岩和混凝土试样,得到了剪切荷载、剪切位移、法向荷载和法向位移之间的关系曲线.试验结果表明,软岩锯齿的法向剪胀角随着剪切位移的增加呈非线性减小,且界面抗剪强度的发挥与法向约束刚度、粗糙体半波长和剪切位移等密切相关;同时,在考虑软岩表面锯齿的弹性压缩对界面剪胀角影响的基础上,采用幂函数拟合了软岩抗剪强度的经验关系式.最后,将试验结果与现有理论模型结果对比,表明了现有模型忽略桩岩界面剪胀角的非线性变化将高估嵌岩灌注桩侧阻力的发挥,这在实际工程中将偏于不安全.     

不同桩侧粗糙度下桩侧阻力分析

为了探讨桩侧的粗糙程度对桩侧阻力的影响,以嵌岩桩为例,通过室内模型试验和数值模拟分析对该问题进行了研究.结果表明桩侧孔壁粗糙程度直接影响着桩侧阻力的大小和分布,也影响着桩侧阻力的发展进程.认识到:当桩侧从光滑到具有一定粗糙度时,桩侧阻力有很大幅度的增长,但随着粗糙度的进一步提高,桩侧阻力提高的幅度将减小.施工时可通过一定的技术方法增加孔壁的粗糙度,从而提高钻孔灌注桩的承载力.     

桩-岩界面胶结作用影响下软岩嵌岩桩承载特征

为研究竖向荷载作用下嵌岩桩桩-岩界面水泥浆的胶结作用对其剪切特性及嵌岩桩的荷载传递性质的影响规律,针对桩-岩界面剪切过程中的胶结弹性变形、滑动剪胀和剪切滑移三个阶段特点,建立了考虑胶结作用影响下的各阶段桩-岩界面剪切本构模型.根据软岩嵌岩桩桩-岩界面粗糙体磨损特性,利用滑移线场法原理分析并得到了嵌岩桩极限剪胀位移.基于荷载传递理论,推导并建立了软岩嵌岩桩荷载传递解析模型.依据所建立的模型并结合实例验证方法,进一步分析了胶结作用影响下桩侧岩石力学特性等因素对嵌岩桩桩侧摩阻力的影响规律.研究结果表明:桩-岩界面胶结作用使剪胀区域桩侧摩阻力明显增大;随着桩侧岩石弹性模量的增大,胶结作用对剪胀区桩侧摩阻力的增强效应越明显,对剪切区域桩侧摩阻力弱化效应越大.当计算软岩嵌岩桩极限承载力时,桩-岩界面胶结作用的影响不可忽略.     

剪切荷载作用下砂岩断裂面粗糙度三维统计分析

利用自主研发煤岩剪切-渗流耦合实验装置与三维立体扫描仪对剪切荷载作用下砂岩断裂面粗糙度三维统计信息进行了实验研究,从其断裂面扫描直观图、断裂面等高线分布图、断裂面剖面轮廓线等方面探讨了剪切荷载作用下砂岩断裂面三维粗糙度分布特性.结果表明:砂岩在剪切荷载作用下发生断裂破坏时,其变形特性曲线变化趋势一致,断裂面直观特征存在个体差异,但断裂面粗糙高度分布均近似于正态分布;沿剪切方向与垂直于剪切方向剖面轮廓线特征不同,不能反映断裂面整体特征;分析了粗糙度参数JRC,RL与RS之间关系,JRC值与RL值之间呈近似线性关系,RS值与JRC平均值线性拟合度相对于JRC与RL值线性拟合度更好,JRC平均值更能反映断裂面整体三维特征.     

贵州软质较破碎白云岩嵌岩桩竖向承载力分析

针对嵌岩桩只适用于完整和较完整岩体,且往往被视为端承桩的情况,以贵州两个工程项目的软质较破白云岩嵌岩桩为研究对象,其持力层岩体均较破碎,通过锚桩横梁反力装置桩基静载荷试验,分析软质较破碎岩嵌岩桩竖向承载力,探讨此类地质条件下嵌岩桩承载特性。研究结果表明,该区软质较破碎白云岩嵌岩桩桩顶荷载-位移曲线主要呈缓变型,沉降由桩身压缩控制,嵌岩段桩侧摩阻力发挥较好,荷载分担比例在30%~50%之间。根据经验参数计算及实测对比研究,得出实测嵌岩桩竖向承载力比计算值高出数倍。     

大直径嵌岩桩桩端极限承载力计算方法

为更加准确获得大直径嵌岩桩桩端极限承载力,假定桩端岩体整体连续滑裂破坏、桩周岩体剪切破坏、桩周岩体微裂纹断裂破坏3种可能的极限状态,基于岩体二维、三维Hoek-Brown(H-B)破坏准则、岩体微裂纹Ⅰ-Ⅱ型复合判据,提出4种大直径嵌岩桩桩端岩体极限承载力的计算方法.引用现有实测数据对所提出的计算方法进行对比分析和验证,结果表明所提出的4种计算方法均比较接近实测值,尤其是基于Ⅰ-Ⅱ型复合判据的桩周岩体微裂纹断裂的桩端极限承载力计算结果与实测值最为接近.进一步研究了大直径嵌岩桩的尺寸效应,研究表明,桩端极限荷载与嵌岩深度及桩径密切相关,嵌岩桩桩端极限荷载随嵌固深度的增大而增大,而随桩径的增大而减小.4种计算方法中基于Ⅰ-Ⅱ型复合判据的桩周岩体微裂纹断裂计算方法与现场实测规律更加相符.     

岩石表面粗糙度的三维定量分析方法

为探究一种三维定量描述岩石表面粗糙程度的方法,通过非接触式超景深三维显微设备获取岩石表面三维彩色等高图,提取并计算三维彩色等高图上各像素点的坐标信息,提出"表面轮廓体积均方根"Vp描述岩石表面粗糙程度。研究结果表明:Vp值与标准轮廓曲线的JRC值、节理剖面系数Rp值均存在指数函数正相关,Vp值越大,粗糙度越大;Vp用于对比粗糙度差异性更直观,克服了粗糙度各向异性及不同方向上存在随机性的理论缺陷,设备及像素点统计方法具有较好的经济性、高效性。     

剑麻纤维复合基材土岩界面剪切性能试验

为揭示剑麻纤维掺量与界面粗糙度对土-岩界面剪切力学性能的影响规律,采用表面起伏的混凝土模块作为岩面相似材料,进行了一系列的改进室内直剪试验,并结合扫描电镜试验进一步分析了剑麻纤维参与强化界面剪切性能的机理。结果表明:剑麻纤维通过提高黏聚力提高土-混凝土界面间的剪切力学性能；纤维添加量为0.8%的土-混凝土界面黏聚力提高80%~500%,内摩擦角提高10%~20%；界面粗糙度主要通过提高黏聚力增强界面剪切力学性能,6.5 mm粗糙度的界面黏聚力增量为7~15.5.kPa,提高20%~300%；对于素土界面和掺纤维界面,粗糙度对土-混凝土界面间剪切力学性能的强化表现为2种模式,加入纤维的界面黏聚力关于粗糙度的增长关系上,粗糙度的最优值出现在较小区间(0~2.5 mm)。     

节理面形貌参数相关性分析及粗糙度量化分级研究

以岩石自然节理面为研究对象,对节理面形貌进行了测量,建立了节理面三维形貌图,在此基础上计算得到了5个形貌参数,以中心线平均高度均方根为基准,对参数之间的相关性进行了研究.在形貌参数测量的基础上,选取3个形貌参数,采用模糊数学方法,实现节理面粗糙度的量化,对粗糙度进行了分级,并对形貌参数与粗糙程度指标之间的依存关系进行了研究.研究表明,中心线平均高度与均方根呈线性正比例关系,峰态系数、偏度系数及表面微凸体倾角均方根值与中心线平均高度均方根值的比值与中心线平均高度的均方根值为幂函数关系.粗糙度量化分级研究结果表明,粗糙度量化分级指标与静摩擦因数及静摩擦角有明显正比例线性关系,静摩擦因数、静摩擦角及量化分级指标与中心线平均高度均方根值的比值与中心线平均高度均方根值为幂函数关系.通过各参数相互之间的定量函数关系,可得到相关性系数,进而实现形貌参数对节理面粗糙程度及摩擦力的估算.     

桩距对陡岩河岸墩式码头群桩基础竖向承载特性影响研究

采用ABAQUS有限元软件建立陡岩群桩系统三维模型,通过改变桩距、桩嵌岩深度等参数,分析陡岩群桩(四边形四桩)的竖向承载特性.研究表明,不同桩距和桩嵌岩深度条件下陡岩群桩(四边形四桩)竖向承载能力,是群桩径向膨胀与桩前岩体缺失效应、桩后岩体增强效应、承台刚度综合作用的体现.当桩距S≥4D时,不宜将承台作刚性假设.当桩距S≥5D时,群桩竖向极限承载力减小幅度、竖向承载群桩效应系数减小幅度均已超过10%(与桩距S=3D的群桩相比).在竖向荷载作用下,随着桩距的增加,承台更易于受压变形,群桩体系空间效应增强,各桩桩顶沉降的差异亦逐渐明显.     

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.     

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.     

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.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.