排序方式: 共有106条查询结果,搜索用时 15 毫秒
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连云港海相软土基本特性与处理方法探讨 总被引:1,自引:0,他引:1
根据连云港地区多条高速公路工程的地质资料,并与我国部分沿海地区软土进行对比,分析连云港海相软土的基本物理力学指标统计特征、抗剪强度特性、固结变形特性以及蠕变特性,并介绍了适合于该海相软土的主要地基处理措施。 相似文献
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边坡土体中的膨胀力是导致膨胀土边坡失稳的主要原因之一。文章基于湿度应力场理论,采用ANSYS软件的热传导分析功能模拟分析边坡的降雨入渗以及膨胀变形,并采用有限元强度折减法对不同条件下边坡安全系数进行计算,分析了膨胀土边坡稳定规律,为膨胀土边坡处治提供理论依据。 相似文献
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山区高速公路弃渣体物理力学特性试验研究 总被引:1,自引:0,他引:1
公路弃土场是一种特殊的人工堆积体,对其进行稳定性分析与评价需要掌握弃渣体的物理力学指标。文章以厦蓉高速公路水都段典型弃土场弃渣体为研究对象,介绍采用现场试验和室内试验方法,对弃渣体的最大干密度和抗剪强度等参数进行研究。通过研究得到:不同颗粒成分弃渣体的最大干密度不同,但在通常推填方式下,弃渣体的强度指标基本不受压实度控制。 相似文献
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重塑非饱和粘性土的抗剪强度参数与物理状态变量的关系研究 总被引:10,自引:2,他引:8
采用分层击实的方法重塑制备三轴试验土样。按5级围压(100kPa,200kPa,300kPa,450kPa,600kPa)完成了土样的三轴压缩UU试验。试验结果表明:在水分状态和密度状态空间,该重塑非饱和粘性土抗剪强度参数的分布具有明显的规律性,但这种规律性不易用简单函数表达。粘聚力的分布呈倾伏的不规则背斜面,内摩擦角的分布呈变形的W型折曲面。粘聚力和内摩擦角与含水量的关系是强非线性的,与干密度的关系总体上是弱非线性的。存在两个特征含水量18 16和16 34,不同密度状态的土样在特征含水量18 16处粘聚力和内摩擦角均取极大值,在特征含水量16 34处内摩擦角均取极小值。 相似文献
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In recent years, the dynamic responses of flexible risers have been the focus of many researchers. Most flexible risers undergo a substantial level of irregular motion from environmental loadings, which involves a continuous slip of helical wires. The slip of helical wires especially leads to a hysteretic effect by reducing the bending stiffness, making it hard to predict the dynamic responses of flexible risers. The current study, as an extension to Part I, presents a new large-scale dynamic analysis method for flexible risers. The suggested method creates a large-scale model for the dynamic analysis that considers a geometric and bending nonlinearity of flexible risers. The kinematics of each beam element is formulated based on a Green-Lagrangian strain and the interaction with the seabed, providing a realistic analysis of flexible risers. In particular, the current study introduces a direct moment correction method that modifies the internal force vector using an improved analytical model. The improved analytical model is assigned at each node of the large-scale model and estimates an accurate bending hysteresis curve considering the effect of shear deformation and varying tension. The suggested method corrects the bending moment and shear force of all beam elements based on the bending hysteresis curves obtained from the improved analytical model, by which a complex bending behavior of flexible risers is reflected in a large-scale domain. As a result, this study achieves a more accurate prediction of the dynamic responses and fatigue damage of flexible risers. A new dynamic analysis program, called OPFLEX, is developed herein based on the suggested analysis method. Using the developed program, the current study conducts several numerical investigations to identify the effect of the shear deformation and varying tension. Consequently, it is confirmed that the shear deformation of internal layers reduces the fatigue damage of helical wires by delaying the increase of internal stress. It is also identified that the effect of varying tension deteriorates the fatigue life of flexible risers through a continuous change of contact pressure during bending. 相似文献
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《铁道标准设计通讯》2016,(1):43-48
针对目前在桥梁地段CRTSⅠ型板式无砟轨道凸台周围树脂离缝,建立CRTSⅠ型板式轨道力学模型,采用可压缩超弹单元模拟树脂层,分析不同扣件阻力、轨道板与CA砂浆间的摩擦阻力条件下的填充树脂层受力。结果表明:在纵向荷载作用下,一旦树脂层发生塑性变形,随着荷载消失和温度下降,树脂层将无法完全回弹,因而产生离缝,并在梁端转角和列车振动荷载作用下进一步发展;在扣件纵向阻力较大时,树脂层会从轨道板下表面与树脂层相接触的位置剪切破坏;轨道板与CA砂浆层之间的摩擦阻力对树脂层的压缩位移和剪切应力的影响不大。 相似文献
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CRTSⅠ型板式无砟轨道路基沉降抬板维修技术研究 总被引:2,自引:2,他引:0
张珍珍 《铁道标准设计通讯》2015,(4):13-15
由于地质条件、建设施工等原因,部分高速铁路路基出现不同程度的沉降,影响行车的平顺性。介绍高速铁路CRTSⅠ型板式无砟轨道路基沉降抬板维修方案的若干技术问题,提出抬板高度及抬板填充材料刚度的合理取值。CRTSⅠ型板式无砟轨道路基沉降可通过扣件调整和抬升轨道板增加充填层厚度等方式进行整治维修。为保证抬升轨道板后凸型挡台受力,建议圆形凸台地段抬板高度最大不超过45 mm,半圆形凸台地段不应进行抬板。轨道板抬升采用的填充材料刚度宜与原CA砂浆层保持一致。 相似文献