BED SHEAR IN EVOLVING SCOUR AT A CYLINDER:A THEORETICAL APPROACH

ＢＥＤＳＨＥＡＲＩＮＥＶＯＬＶＩＮＧＳＣＯＵＲＡＴＡＣＹＬＩＮＤＥＲ：ＡＴＨＥＯＲＥＴＩＣＡＬＡＰＰＲＯＡＣＨＳｕｂｈａｓｉｓｈＤＥＹ１ａｎｄＳｒｉｊｉｂＫ．ＫＡＲ２Ａｂｓｔｒａｃｔ：Ｔｈｅｔｅｍｐｏｒａｌｖａｒｉａｔｉｏｎｏｆｓｈｅａｒｓｔｒｅｓｓ...     

方解石多晶集合体的高速率简单剪切变形实验研究

本文介绍了方解石多晶集合体在高应变率(373S^-1到1507S^-1)下简单剪切变形实验,结果表明,破裂形式和应变率有关,随着应变率的增加,从晶间微破裂为主变为晶内微破裂和粉碎为主。     

内蒙古东五分子地区韧性剪切变质作用的特征

东五分子地区花岗-绿岩地体经受了三种类型变质作用的改造。韧性剪切带不仅控制了区域变质岩组合的分布,而且也导致其变质作用的强度出现了逆转序列。根据岩石的结构、碎斑含量及矿物成分,韧性剪切变质岩划分为三类,其共同特点是具有碎斑结构。其变形结构分为单矿物型及组合型。同一块韧性剪切变质岩由处在单变平衡的一组矿物组成。根据岩石变形及重结晶的特点,结合其产状,确定出两种不同类型韧性剪切变质带。共生矿物对的研究证明它们形成于地壳不同深度及温度、压力条件。本区的金矿化、运移、沉淀与韧性剪切变质带紧密相关。     

论板块运动的驱动力

本文从动力学的角度讨论了板块运动的驱动机理,并提出了计算板块扩张速度的公式,然后求出了不同类型板块的扩张速度。用此公式所计算出的板块扩张速度与实际观测速度很符合。     

动态聚类-模糊模式识别及其应用

本文以模糊子集论为指导,在迪戴的DCM法的基础上提出了动态聚类-模糊模式识别方法。实际上,它是一种新的模糊聚类的方法。该方法以DCM法的动态聚类部分做为原始数据变换的手段,而将迪戴的强模式概念推广为模糊模式,将强模式识别推广为模糊模式识别。此外,还提出了模糊模式间联系度的概念,从而解决了类间联系、类内典型个体、类间过渡个体、个体对各类的隶属程度以及内部有某种演化趋势的类别的划分等问题。文章还给出了该方法的数学模型和算法概要。最后,通过一个在地质学中的应用实例,说明了该方法的应用效果。     

Further Studies Of Atmospheric Turbulence In Layers Near The Surface: Scaling The Tke Budget Above The Roughness Sublayer

The second of two experimental studies of the TKE budget conducted on sites of different roughness is described, and results are compared. The first took place within a shallow layer above a small field of mostly bare, cultivated soil; the second was carried out above a roughness sublayer of significant depth on an extensive plain of tall dry grass. Budget terms observed in the second study were scaled with a modified u which compensated for effects of an unusually large stress gradient and ensured that the _m functions would be collinear. By showing that the modification becomes negligible in smaller gradients, it is demonstrated that in normal conditions, budgets observed above significant roughness sublayers should be normalized by scaling in terms of the unreduced Reynolds stress at the sublayer's upper surface. This procedure is shown to be consistent with the expectation that TKE budgets in layers near the surface all scale in fundamentally the same way.Other findings include: (1) the fact that most _m functions previously reported are not quite collinear is attributed to a type of overspeeding known to affect three-cup anemometers; (2) revised _m functions, collinear and largely free of the effects of overspeeding, are determined from a well-established characteristic of the linear _m relation for the stable case; (3) data that define collinear _m functions can also be represented with single hyperbolic curves; (4) dissipation is found to be 10 to 15% too small to balance total TKE production in unstable and neutral conditions and to decrease with increasing z/L in thestable regime; and (5) new relations for based on the observed behaviour of the dissipation deficit provide an improved closure for the set of equations that express the budget terms as functions of _m and z/L.     

新型灌浆材料在已建砌体结构抗震加固中的应用

具有悠久历史的石结构是砌体结构的重要组成部分，本文作者经广泛调研和试验分析：(1)提出以石粉为集料对石砌体进行抗震加固，寓环保与防灾于一体；(2)给出新型浆体配比和复合砂浆的强度等级，阐述加固技术和方法，建立灌浆石砌体抗震抗剪强度公式；(3)阐明抗震验算方法，提出基于模糊随机可靠理论的可靠性分析方法。     

砂土的抗剪强度与干密度的曲线拟合

利用曲线拟合的最小二乘法原理，确定砂土在某垂直压力下的抗剪强度与干密度的关系，并绘制曲线图，可避免人工处理数据的随意性，减小了误差。     

Effect of rod friction on vane shear tests in very soft organic harbour mud

Very soft organic harbour mud is increasingly used as a filling and construction material in harbour construction and reorganization. The undrained shear strength of such soft sediments is the critical geotechnical soil parameter with regard to any specific construction design. Field and laboratory vane shear testing is a standard method to quickly determine this important parameter. So far, the effect of rod friction on vane shear tests in very soft organic soils is unclear. In this study we present results from laboratory experiments on harbour mud from a construction site in northern Germany. Relations among vane and rod geometry, penetration depth, water content, rod friction and undrained shear strength are derived. Based on these relations the influence of rod friction on vane shear test results is investigated. The results indicate that field and laboratory vane shear test measurements may be significantly influenced by rod friction. Methods are proposed to correct for the rod influence, which is shown to increase with rising water contents.     

Analysis of kinematic seismic response of tapered piles

In the present work, a two-phase analysis is used to assess the lateral movement of a tapered pile due to kinematic seismic loading resulted from earthquakes. First, the free-field horizontal displacement of the ground due to earthquake is estimated using available theory of wave propagation. Second, these estimated soil movements are imposed on the taper pile in a closed-form solution to compute the pile response. The governing differential equation for an arbitrary pile segment is obtained, which includes the free-field horizontal movement estimated from the first phase. The equation is solved explicitly to obtain the horizontal deflection. Parametric studies show that tapered piles tend to be more flexible than uniform piles of the same volume and length under earthquake loading, which is soundly interesting.