浅谈水泥搅拌桩在建筑工程软基处理的应用

对于地下水含量丰富地块,建筑基础大部分采用桩基础,作为建筑物的基础或基础加固处理的方法,如预制桩、灌注摩擦桩、端承桩、水泥搅拌桩等,因此在不同的地质情况下如何选用适合的桩基础施工方案是达到设计标准的条件下同时降低工程成本的首选.现就基础施工中,因工期紧,采用水泥搅拌桩处理基础下5-10米软土层,在达到设计标准的条件下同时确保施工工期的应用.     

人工挖孔桩施工中的几个问题

介绍了人工挖孔桩施工中出现流砂、地基沉降的防治措施，孔身混凝土的浇筑方法及施工中的安全措施，以便保证人工挖孔桩的施工质量。     

机场航站楼桩基基础施工技术探讨

桩基基础施工技术种类繁多,常见的木桩、钢桩、钢筋混凝土桩等。在机场航站楼施工中绝大部分为钢筋混凝土桩,结合贵州省贵阳市龙洞堡国际机场1号航站楼扩建工程2标段实际情况,分别从桩基人工开挖,机械开挖等方面对机场航站楼桩基基础施工技术探讨。研究表明:机场航站楼桩基础施工技术,施工更加稳定,安全性高,施工工期更加容易掌控,值得大范围推广应用。     

大直径挖孔桩在桥梁工程中的应用研究

大直径人工挖孔桩在建筑工程桩基中已得到较为广泛的应用,由于桥梁工程基础具有其自身的特点,施工中要格外注意.本文结合作者多年工作经验,详细阐述了大直径扩底桩的承载机理,大直径扩底桩的设计与施工,几种特殊问题的技术处理以供读者参考.     

对预制桩施工中常见几个问题的探讨

对预制桩施工中常见的几个问题进行分析，并提出相应的措施。     

锚杆静压桩在地基加固中的应用

通过介绍锚杆静压桩的施工原理、《规范》要求和施工实例，阐述了锚杆静压桩的作用、工作原理、施工方法和施工要点。     

摩擦桩施工问题的处理方法

在摩擦桩施工的过程中，容易出现断桩、坍孔、缺陷桩、成孔困难等问题。根据芜湖长江大桥施工中出现的以上问题，分析其产生的原因，提出几种处理方案。     

高层建筑基桩岩石爆破设计与施工技术

对于城市中的高层建筑基础工程岩石爆破。施工环境情况具有特殊性，该文介绍了基础工程桩井岩石爆破开挖设计与施工时爆破参数的选取、爆破器材的选择、安全技术措施和施工组织，避免桩井圈岩产生有害结构裂缝，确保工程施工的安全和质量。     

砂性土地基深层搅拌桩施工要点及注意事项

在分析深层搅拌桩复合地基适用条件的基础上，结合某深层搅拌桩工程，侧重论述了砂性土深层搅拌桩施工要点和施工中的注意事项。     

论钢板桩围堰的施工设计

本文以某跨海大桥(起止里程为6250m,基础均为钻孔桩基础、圆形承台)在滩涂区设置围堰为倒,从钢板桩围堰的组成、结构、施工等方面系统论述了钢板桩围堰的施工设计.     

港口工程软基处理中振冲碎石桩的应用与检测

通过在某中心渔港工程中采用振冲碎石桩工艺对软地基进行加固的施工进行系统的总结。对比振冲碎石桩在道路、建筑等工程中的应用有诸多不同,在施工工艺、质量控制、加固效果检验有其独特之处,介绍振冲碎石桩在水工港口工程软地基处理的工艺原理、工艺流流程、质量控制的方法及效果、采用重型动力触探试验进行检测的方法及结果。     

挤扩支盘灌注混凝土桩在工程中的应用与分析

厂房车间跨度大、荷载大及抗震要求对桩基础应用提出了较高要求。文章通过对挤扩支盘混凝土灌注桩的计算、测试、受力分析及在工程实践中的应用研究,较好地解决了工程基础的要求,取得了明显的经济效益。     

浅谈钻孔灌注桩的施工技术和质量控制

钻孔灌注桩属隐蔽工程，成桩后质量检查比较困难，在施工各个环节应充分重视，精心施工，保证工程质量。     

Do examinations stakes moderate the test anxiety–examination performance relationship?

The study reported here aimed to establish whether the stakes of examinations taken by students in the final two years of compulsory education in the UK were associated with degree of self‐reported examination anxiety, and whether examination stakes moderated the anxiety–examination grade relationship. Data were collected from 615 students who were due to take examinations conceptualised as high stakes (a terminal examination), mid stakes (a modular examination), or low stakes (a mock examination). Findings suggested that students reported the lowest levels of anxiety and attained the highest grades in the mid stakes examination. Regression analysis suggested that examination stakes do moderate the inverse anxiety–grade relationship, but the effect for high stakes examinations was not in the expected direction. Results are interpreted in the context of limitations to this study’s design. Factors associated with the different timing of the examinations may have influenced results. Due to design limitations, these findings should only be considered provisional and an attempt should be made to replicate the findings using a more robust design. This study highlights the difficulties with designing studies and collecting data in an applied educational context.     

The Effect of Differential Motivation on IRT Linking

The purpose of this study was to investigate whether simulated differential motivation between the stakes for operational tests and anchor items produces an invalid linking result if the Rasch model is used to link the operational tests. This was done for an external anchor design and a variation of a pretest design. The study also investigated whether a constrained mixture Rasch model could identify latent classes in such a way that one latent class represented high‐stakes responding while the other represented low‐stakes responding. The results indicated that for an external anchor design, the Rasch linking result was only biased when the motivation level differed between the subpopulations to which the anchor items were administered. However, the mixture Rasch model did not identify the classes representing low‐stakes and high‐stakes responding. When a pretest design was used to link the operational tests by means of a Rasch model, the linking result was found to be biased in each condition. Bias increased as percentage of students showing low‐stakes responding to the anchor items increased. The mixture Rasch model only identified the classes representing low‐stakes and high‐stakes responding under a limited number of conditions.     

Devising inequality: a Bernsteinian analysis of high‐stakes testing and social reproduction in education

High‐stakes, standardized testing has become the central tool for educational reform and regulation in many industrialized nations in the world, and it has been implemented with particular intensity in the United States and the United Kingdom. Drawing on research on high‐stakes testing and its effect on classroom practice and pedagogic discourse in the United States, the present paper applies Bernstein’s concept of the pedagogic device to explain how high‐stakes tests operate as a relay in the reproduction of dominant social relations in education. This analysis finds that high‐stakes tests, through the structuring of knowledge, actively select and regulate student identities, and thus contribute to the selection and regulation of students’ educational success.     

Test Stakes and Item Format Interactions

The effects of test consequences, response formats (multiple choice or constructed response), gender, and ethnicity were studied for the math and science sections of a high school diploma endorsement test. There was an interaction between response format and test consequences: Under both response formats, students performed better under high stakes (diploma endorsement) than under low stakes (pilot test), but the difference was larger for the constructed response items. Gender and ethnicity did not interact with test stakes; the means of all groups increased when the test had high stakes. Gender interacted with format; boys scored higher than girls on multiple-choice items, girls scored higher than boys on constructed-response items.     

Raising the Stakes of Test Administration: The Impact on Student Performance on the National Assessment of Educational Progress

This article briefly reviews the current discussion of the effects of test administration conditions (i.e., testing stakes), and the motivational levels associated with them, on achievement test performance. The non-experimental study presented here investigates whether differences in test administration conditions and presumed levels of motivation engendered by different testing environments affect student performance on National Assessment of Educational Progress (NAEP) administrations. The testing conditions under study are the "low-stakes" environment of the current NAG administration and a higher stakes environment typified by many state assessment programs. The results suggest that in comparison to a "moderate-stakes" testing environment NAEP does not seriously underestimate achievement levels. However, the results cannot lead to the conclusion that student achievement is unrelated to testing stakes. Nor can one conclude that substantially raising the stakes of NAEP would not be accompanied by an increase in achievement scores.     

Does pragmatism trump motivation in college students’ preferences for examination formats?

Proponents of performance assessments purport that they allow more options for student choice and autonomy and, therefore, are more motivating and more preferred by students. This study explored the role of stakes and the student’s familiarity with the format in these examination preferences. A survey of 148 college students suggested that: their familiarity with open-ended assessments led students to prefer them without reference to stakes; they tended to prefer closed assessments when the stakes are low but open formats when the stakes are high; and their goal orientation had no relationship with these decisions. In the end, students seemed to be rather pragmatic and protective of their grades regardless of their goal orientations, which is only natural. The students’ goal orientations appear, then, to be desiderata for both them and their instructors, but a graded environment stifles their full operation.     

Can Knowledge of Erasure Behavior be Used as an Indicator of Possible Cheating?

What is the typical amount of student answer‐changing that takes place in a low‐stakes test environment? Can we use this information to look for evidence of improper answer‐changing (cheating) on high‐stakes test?