共查询到10条相似文献,搜索用时 129 毫秒
1.
Muang-sangop Seniwongse 《Canadian Metallurgical Quarterly》2010,16(4):164-169
This paper presents comprehensive and practical engineering review (not mathematics or computer science paper) of the observed behavior of the two types of slabs that have been used for the bottom floor slabs, at grade and underground, of buildings in the United States and overseas. The typical design of the slab-on-grade (SOG) built in the United States is described. The design requires only nominal reinforcing steel, but modern day design also requires ground preparation and improvement as necessary, including underslab perforated drainage pipe network embedded in the granular subbase, riser pipes, and a series of pumps. Sealing at all slab isolation joints and waterproofing membrane or water barrier system are provided for water tightness. The framed slab is supported directly on the building framing and on the building foundation. The design can accommodate the soil and underground water pressure and in itself is watertight as the slab is cast monolithically with the structural walls and footings. The behavior of the SOG depends so much on the behavior (soil properties) of the soil strata on which the slab is resting on. It is sensitive to the variation of the soil conditions at and around building foundations, leading to uneven bumpy and cracked slab and leaking basement. These were demonstrated in the report of short- and long-term performances of various projects in Thailand and United States in the past 25 years. The paper refers to various analysis and design techniques that may be used to improve the design of both the SOG and the framed slab for serviceability and economy. It is concluded that both types of slabs may be selected to suit the functions and serviceability requirements of the buildings. The SOG requires less concrete and reinforcement than those for the framed slab counterpart, but when all other factors are considered including additional underslab drainage and pump system, operating, and long-term performance and maintenance, the overall costs of both slabs may not be far apart, yet the performance and integrity of the framed slab will certainly be superior. 相似文献
2.
Sheng-hong Chen Ming-yi Xu Isam Shahrour Peter Egger 《Canadian Metallurgical Quarterly》2003,129(11):977-986
This paper presents the use of the trial load method and the block element method with elastoviscoplastic discontinuities for analysis of arch dams. The arch dam is considered as an arch-cantilever system and the foundation as a block element system. With the displacement compatibility condition at the contact surface of the dam and the foundation (including abutment), the governing equations of the arch dam and foundation are established. These methods are used for the analysis of the double curvature arch dam with complex geology conditions of the Xiaowan Hydroelectric Project in China. The deformation and stress states in both the dam body and the foundation are determined. Furthermore, the stability safety factors of the foundation and the abutment are calculated at the same time, which allows for an optimal design of the arch dam considering the strength, the deformation and the stability of the dam and foundation. 相似文献
3.
4.
Introduces the articles appearing in this issue of Psychology of Aesthetics, Creativity, and the Arts. Of particular interest in this issue are the breadth and the rigor of the methodology that underlie the substantive and theoretical issues addressed in the work. The issue begins with an article from Dean Keith Simonton, who looks at the idea of what success in film is and how different indicators of success (critical, box office, etc.) are related to one another over the life of a film. Paul Silvia, James C. Kaufman, and Jean Pretz then address the question of the domain specificity of creativity. The third article shifts to the field of music and looks at the relationship between personality characteristics and how people use music in their lives. The next article reports the results of an experimental design that looked at recognition of objects in cubist paintings and pupil dilation after having made a classification of an object. The next article looks at differences in the motivations and personality characteristics of individuals who visit modern art museums versus ancient art museums. Next, Patricia Stokes uses the problem-solving approaches of Reitman and Simon in a case study examining the sculpture of Richard Serra. The issue concludes with an analysis of the idea of “lived experience” as it relates to the psychology of aesthetics and art making. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
6.
Renata Kotynia Radoslaw Walendziak Iwan Stoecklin Urs Meier 《Canadian Metallurgical Quarterly》2011,15(2):168-180
This paper presents the test results of reinforced concrete slabs strengthened with prestressed and gradually anchored carbon fiber–reinforced polymer (CFRP) strips under monotonic and cyclic loading. To take full advantage of the externally bonded CFRP technique, it is beneficial to apply the laminates in a prestressed state, which relieves the stress in the steel reinforcement and reduces crack widths and deflection. The aim of the monotonic tests was to determine the strengthening efficiency of the new prestressing technique and to investigate serviceability and ultimate states. The cyclic tests were performed to identify the fatigue behavior of the strengthened slabs and to investigate the influence of long-term cyclic loading and elevated temperature on the bond properties of the prestressed CFRP laminates and the ductility and flexural strength of the strengthened slabs. A nonlinear analytical model of reinforced concrete members strengthened with passive and prestressed CFRP strips under static loading is proposed in the paper. A comparison of the experimental and predicted results reveals an excellent agreement in the full range of loading. 相似文献
7.
8.
The natural frequencies and the out-of-plane vibration modes of one-way masonry walls strengthened with composite materials are studied. Due to the inherent nonlinear behavior of the masonry wall, the dynamic characteristics depend on the level of out-of-plane load (mechanical load or forced out-of-plane deflections) and the resulting cracking, nonlinear behavior of the mortar material, and debonding of the composite system. In order to account for the nonlinearity and the accumulation of damage, a general nonlinear dynamic model of the strengthened wall is developed. The model is mathematically decomposed into a nonlinear static analysis phase, in which the static response and the corresponding residual mechanical properties are determined, and a free vibration analysis phase, in which the dynamic characteristics are determined. The governing nonlinear differential equations of the first phase, the linear differential eigenvalue problem corresponding to the second phase, and the solution strategies are derived. Two numerical examples that examine the capabilities of the model and study the dynamic properties of the strengthened wall are presented. The model is supported and verified through comparison with a step-by-step time integration analysis, and comparison with experimental results of a full-scale strengthened wall under impulse loading. The results show that the strengthening system significantly affects the natural frequencies of the wall, modifies its modes of vibration, and restrains the deterioration of the dynamic properties with the increase of load. The quantification of these effects contributes to the understanding of the performance of damaged strengthened walls under dynamic and seismic loads. 相似文献
9.
地下矿产资源开采过程中,频繁的应力扰动会对深部硬岩造成一定的损伤。硬岩内部孔隙和裂隙在高地应力和高渗透压的状态下迅速扩展贯通,严重威胁岩体工程的安全和稳定性。针对损伤花岗岩开展了一系列应力—渗流耦合试验,结合CT扫描,考虑渗透压、围压和损伤程度等因素的影响,综合分析了损伤岩石在应力—渗流耦合作用下的力学和渗流特性。试验结果表明:随着损伤程度的增加,岩样孔隙及裂隙体积呈现出从平缓增加、稳步增加到急剧增加的变化趋势;在围压相同的情况下,岩样的峰值强度随着渗透压的增加呈线性减小,渗透压对损伤花岗岩的强度具有明显的弱化效应,且弱化程度与围压无关;损伤程度越大,裂隙发育程度越高,渗透率越大,同时,孔隙及裂隙的发育程度可用于表征渗透率的大小。 相似文献
10.
Reviews the book, Psychologie sociale des medias edited by Pascal Marchand (2004). This work consists of two parts, each one having distinct characteristics. The first part presents a summary of traditional and recent research in psychology, which is devoted to various questions concerning the influence of the media. Specifically it covers effects of the television and the representations of violence and sexuality. This part will be of most interest to those concerned with social psychology or of psychology of the media. The second part has as a discussion thread a socio-cognitive orientation and comprises seven chapters which treat more precise questions relating to the psychological aspects of the media and their influence. The various chapters present either mainly theoretical contents, focusing on speech and rhetoric, but in some chapters there is a combination of theoretical discussions and empirical data. The second part is specialized, but also, more "European" in regards to its content. The two parts of the work are distinct. While the first part relates to mainly the effects of the entertainment and the accounts, the second part relates almost exclusively to the media of information, journalism and the great stakes related on the communication and persuasion in the political life and publicity. Although the two parts of the work are different in structure and their content, they adopt both a socio-cognitive prospect essential for theory and research in psychology for the media. Overall, this work is an interesting addition to the fields of social psychology and social cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献