褥垫层厚度、模量变化对复合地基应力场影响的数值模拟研究

褥垫层是刚性桩和半刚性桩复合地基的核心技术之一。为探求褥垫层厚度、模量变化对复合地基应力场产生的影响,利用大型通用有限元程序ANSYS,进行了不同褥垫层厚度、模量的复合地基数值模拟研究,获得了褥垫层厚度、模量变化对复合地基桩土应力比、桩身应力、土体应力等产生的影响,为复合地基的工程设计提供了数据支持。     

复合地基褥垫层的作用机理及设计探讨

通过对复舍地基条件下桩土共同作用以及褥垫层作用机理的分析,强调了褥垫层在复合地基设计中的重要作用,并简要介绍了各种复合地基褥垫层的设计方法.     

复合地基褥垫层作用规律的模型试验研究

本文根据相似理论,采用国内最大比例尺,在三维试验台架中进行不同褥垫层厚度的复合地基多组模型试验,对复合地基褥垫层的作用随厚度变化的规律进行了研究。     

浅析CFG桩复合地基设计计算

简述CFG桩复合地基的基本概念,分析CFG桩复合地基承载力计算和CFG桩复合地基变形计算,以及单桩竖向承载力特征值的取值要求和褥垫层厚度确定。     

关于核心筒基础筏板褥垫层施工的探讨

应用计算机技术分析、解决大坡度褥垫层现场施工问题,保证CFG桩复合地基承栽模式,为同种结构的CFG复合地基中带坡度褥垫层的施工提供经验借鉴．根据具体工程实例,运用AutoCAD和Excel计算机技术对核心筒结构筏板基础处的施工方法进行详细地分析和论证．     

CFG桩复合地基中褥垫层的抗震性能分析

水平地震时,用水平剪力代替上部结构的地震作用后,利用剪力层法求解出了褥垫层的运动微分方程,从而可反演出褥垫层内的水平动剪力传递过程.由实例分析可知放置适当厚度的褥垫层,可减少了上部结构的水平地震作用;褥垫层的存在,在一定程度上提高了整个CFG桩复合地基的抗震性能.     

CFG桩复合地基中褥垫层的抗震性能分析

水平地震时，用水平剪力代替上部结构的地震作用后，利用剪力层法求解出了褥垫层的运动微分方程，从而可反演出褥垫层内的水平动剪力传递过程。由实例分析可知：放置适当厚度的褥垫层，可减少了上部结构的水平地震作用；褥垫层的存在，在一定程度上提高了整个CFG桩复合地基的抗震性能。     

复合地基技术的发展及应用中若干问题探讨

介绍了复合地基技术的发展概况，着重论述了一些相关的概念，如复合地基、地基处理、复合桩基、按沉降控制设计的疏桩桩基等。通过受力机理的分析，阐明了设置褥垫层与否及桩与基础连接与否并不是复合地基的必要条件，并提出了今后复合地基的重点研究方向。     

褥垫层在CFG桩中的作用

褥垫层对提高CFG桩的承载力有较大的作用,主要分析褥垫层对对保证桩土共同承担荷载的影响、褥垫层在CFG桩中对提高地基承载力所起到的作用,从经济技术等方面比较,给出在实际工程中应该采取的褥垫层厚度。     

石粉CFG桩在路基工程中应用分析

文章分析石粉CFG桩在公路中应用,阐述了石粉CFG桩复合地基设计,介绍石粉CFG桩设计长度、桩径、桩间距、桩身强度、桩身材料、褥垫层及布桩形式、单桩及复合地基承载力,通过施工及质量检测达到了设计标准,为石粉CFG桩施工提供一定参考。     

CFG桩复合地基变形计算方法探讨

对规范推荐的CFG桩复合地基变形的计算方法进行修正,提出修正规范法。     

堆载作用对邻近CFG桩复合地基影响的数值模拟研究

通过有限元分析软件ANSYS11.0,对邻近地面堆载作用下已承载CFG桩复合地基的力学性状进行了分析,对已承载CFG桩复合地基中桩体在不同的地面堆载荷载、堆载作用位置、承台受荷状态以及土体压缩模量等工况中的性状进行了研究,进而分析得出堆载的作用位置、大小以及复合地基所在场地范围内土体压缩模量是几个比较重要的影响因素,对临近堆载的CFG桩复合地基的力学性状影响较大。     

散体材料桩和水泥桩复合地基固结理论研究综述

复合地基在地基处理中具有十分重要的地位,其用于加固地基,增强地基承载力和减小地基沉降具有良好的效果,因而在工程中被广泛采用。由于研究复合地基的固结是研究复合地基加固机理的主要内容之一,土体的固结直接影响复合地基的变形和承载能力。因此,有必要对复合地基的固结理论进行全面、系统地认识。本文主要对散体材料桩和水泥桩复合地基的固结理论进行综述,阐述了复合地基固结理论研究的现状和取得的理论成果。     

聚合物/蒙脱土复合材料的研究进展

综述了聚合物／蒙脱土复合材料的国内外进展,简要介绍了蒙脱土有机化改性的原理和制备的方法,同时综述了聚合物／蒙脱土复合材料制备的原理和制备的方法,其中主要介绍了聚合物／蒙脱土复合材料的制备方法中的原位插层聚合法,聚合物溶液插层法,聚合物熔融插层法。     

《组合结构》课程教学方法的探讨

根据对《组合结构》课程理解和教学中的体会,就如何使学生更好地学习和掌握《组合结构》这门课程知识,如何培养学生的实践能力和创新能力,通过对课程内容的调整、改进和更新使其更加符合学生的实际情况和社会需求,提出了一些见解。     

Comparison of the General Ability Measure for Adults and the Kaufman Adolescent and Adult Intelligence Test with college students

Ninety‐four college students were administered the GAMA and KAIT. GAMA IQs were significantly and moderately correlated with KAIT Fluid, Crystallized and Composite IQs, supporting the convergent validity of this instrument. Although significant correlations between measures emerged and nonsignificant differences were found between mean scores across these instruments, GAMA IQ scores did not accurately predict KAIT Composite IQ scores when GAMA IQ scores were compared to KAIT Composite IQs. Similarly, when the sample was divided into two groups by ability level, GAMA IQs accurately estimated the intelligence for individuals of Average and Below Average intelligence, but underestimated the KAIT Composite IQ scores by 4 points for the Above Average group. Implications of the findings are discussed and suggestions for future research are provided. © 2002, Wiley Periodicals, Inc.     

沪深股市波动相关性的实证研究

文章选取上证指数和深成指数的收益率数据,使用时间序列分析的方法,利用向量自回归模型(VAR)及脉冲响应函数探讨了两个股市之间波动相关性的问题,得到两个市场存在明显的联动关系,通过上证综指滞后五期的收益可以预期深圳成指当期的收益,同样,通过深圳成指滞后六期的收益可以预期上证综指的当期收益.     

The comparability of the Test of Cognitive Skills with the Wechsler Intelligence Scale for Children-Revised and the Stanford-Binet: Fourth edition with gifted children

The comparability of the Test of Cognitive Skills (TCS) with the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Stanford-Binet Intelligence Scale: Fourth Edition (SBIV) with 75 elementary- and middle-school-aged gifted students was investigated. Results indicated that the mean Cognitive Skills Index was about 6 points higher than the WISC-R FSIQ and about 9 points higher than the SBIV Composite score. Correlation coefficients between the TCS Cognitive Skills Index and the SBIV Composite score and the WISC-R FSIQ were.51 and.41, respectively. Absolute differences between individual scores revealed that 44% of the students' SBIV Composite scores were more than 10 points different than their Cognitive Skills Index, and 28% of the students' WISC-R FSIQ scores were more than 10 points different. The results indicated limited comparability between the TCS and WISC-R and SBIV. The implications of these findings and future research questions are discussed.     

Concurrent validity of the Stanford-Binet: Fourth edition and Kaufman assessment battery for children with learning-disabled students

This study examined the concurrent validity of the composite and area scores of the Stanford-Binet Intelligence Scale: Fourth Edition (SBIV) and the Mental Processing Composite and global scale scores of the Kaufman Assessment Battery for Children (K-ABC). The tenability of interpreting the SBIV using the fluid/crystallized model, as suggested by the authors, was also considered. The subjects were 30 Black, learning-disabled elementary school students. Results of a t test indicated that the Mental Processing Composite score of the K-ABC was significantly higher than the SBIV Composite score. Moderate to high correlations were obtained when SBIV composite and area scores were compared to K-ABC composite and scale scores, reflecting a positive relationship between the two tests. The measures of fluid abilities (K-ABC Composite score; SBIV Abstract/Visual Reasoning) were highly correlated. The results of a multiple regression analysis indicated a moderate degree of correlation among the measures of crystallized ability (K-ABC Achievement; SBIV Verbal Reasoning and Quantitative Reasoning). The findings of this study demonstrated adequate concurrent validity for the SBIV. In addition, the results provided limited support for describing test results utilizing the fluid/crystallized interpretation model. Further research is suggested in order to examine other validity issues, such as classification of special education students and the SBIV's relationship to other similar instruments.     

民间慈善基金会组织对美国高等教育的影响

慈善基金会是美国社会颇富特色的一种民间组织,在美国高等教育的发展历程中扮演着重要和独特的角色。民间慈善基金会组织的产生源于美国独特的社会文化背景、富人群体的涌现、政府部门的税收政策以及源远流长的宗教信仰等,它们以促进社会公共福利和资助社会慈善公益事业为宗旨,其类型分为独立基金会、公司基金会、社区基金会、运作型基金会。民间慈善基金会组织自产生以来就十分重视和支持美国高等教育的发展,它们在增加美国高校办学经费、促进高校科学研究、关注高校弱势群体、保障高校教师生活、推动和促进美国医学高等教育发展等方面发挥了积极的作用,成为推动美国高等教育快速向前发展的特殊群体和重要力量。