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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Komunitní nadace a jejich specifika / Community foundations and their specifics

Procházková, Jitka January 2018 (has links)
Today, community foundations undoubtedly play a significant role in building community philanthropy and strengthening civil society through civic engagement. They are unique by their specific connection to the community, ie. to a particular geographically defined area, where this foundation financially supports activities, events, individuals or groups in the form of grants. These grants provide from a collection of donated funds from many donors and the impact on the community is that it addresses its diverse problems and needs. Thanks to this collection and the endowment can address these needs in the long run. In the submitted diploma thesis, is based on analysis of professional literature, the specifics of community foundations are derived and based on the analysis of the documents of the foundations, it is shown how many Czech community foundations correspond to this ideal. Keywords: Community, foundations, community foundations, community philanthropy, social capital, board of directors, community foundation history, foundation growth, specifics of community foundations
492

Rocking shear wall foundations in regions of moderate seismicity

Van der Merwe, Johann Eduard 12 1900 (has links)
Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: In regions of moderate seismicity it has been shown that a suitable structural system is created when designing the shear wall with a plastic hinge zone at the lower part of the wall, with the shear walls resisting lateral loads and all other structural elements designed to resist gravity loads. A suitably stiff foundation is required for the assumption of plastic hinge zones to hold true. This foundation should have limited rotation and should remain elastic when lateral loads are applied to the structure. Ensuring a foundation with a greater capacity than the shear wall results in excessively large shear wall foundations being required in areas of moderate seismicity for buildings with no basement level. This study aims to investigate the feasibility of reducing the size of shear wall foundations in areas of moderate seismicity for buildings with no basement level. The investigation is aimed at allowing shear wall foundation rocking and taking into account the contribution of structural frames to the lateral stiffness of the structure. An example building was chosen to investigate this possibility. Firstly, lateral force-displacement capacities were determined for a shear wall and an internal reinforced concrete frame of this investigated building. Nonlinear momentrotation behaviour was determined for the wall foundation size that would traditionally be required as well as for six other smaller foundations. The above capacity curves against lateral loads were then used to compile a simplified model of the structural systems assumed to contribute to the lateral stiffness of the building. This simplified model therefore combined the effect of the shear wall, internal frame and wall foundation. Nonlinear time-history analyses were performed on this simplified model to investigate the dynamic response of the structure with different wall foundation sizes. By assessing response results on a global and local scale, it was observed that significantly smaller shear wall foundations are possible when allowing foundation rocking and taking into account the contribution of other structural elements to the lateral stiffness of the building. / AFRIKAANSE OPSOMMING: Daar is reeds getoon dat ʼn voldoende strukturele sisteem verkry word in gebiede van gematigde seismiese risiko indien ʼn skuifmuur ontwerp word met ʼn plastiese skarnier sone naby die ondersteuning van die muur. Skuifmure word dan ontwerp om weerstand te bied teen laterale kragte met alle ander strukturele elemente ontwerp om gravitasie kragte te weerstaan. Vir die aanname van plastiese skarnier sones om geldig te wees word ʼn fondasie met voldoende styfheid benodig. Só ʼn fondasie moet beperkte rotasie toelaat en moet elasties bly wanneer laterale kragte aan die struktuur aangewend word. ʼn Fondasie met ʼn groter kapasiteit as dié van die skuifmuur lei daartoe dat uitermate groot fondasies benodig word in gebiede van gematigde seismiese risiko vir geboue met geen kelder vlak. Hierdie studie is daarop gemik om die moontlikheid van kleiner skuifmuur fondasies te ondersoek vir geboue met geen kelder vlak in gebiede van gematigde seismiese risiko. Die ondersoek het ten doel om skuifmuur fondasie wieg aksie toe te laat en die bydrae van strukturele rame tot die laterale styfheid van die struktuur in ag te neem. Eerstens is die laterale krag-verplasing kapasiteit van ʼn skuifmuur en ʼn interne gewapende beton raam van die gekose gebou bepaal. Nie-lineêre moment-rotasie gedrag is bepaal vir die skuifmuur fondasie grootte wat tradisioneel benodig sou word asook vir ses ander kleiner fondasie grotes. Die bogenoemde kapasiteit kurwes is gebruik om ʼn vereenvoudigde model van die strukturele sisteme wat aanvaar word om laterale styfheid tot die gebou te verleen, op te stel. Hierdie vereenvoudigde model kombineer gevolglik die effek van die skuifmuur, interne raam en skuifmuur fondasie. Nie-lineêre tydgeskiedenis analises is uitgevoer op die vereenvoudigde model ten einde die dinamiese reaksie van die struktuur te ondersoek vir verskillende fondasie grotes. Resultate is beoordeel op ʼn globale en lokale vlak. Daar is waargeneem dat aansienlik kleiner skuifmuur fondasies moontlik is deur wieg aksie van die fondasie toe te laat en die bydrae van ander strukturele elemente tot die laterale styfheid van die gebou in ag te neem.
493

Social capital influences upon Internet usage of rural Guatemalan English teachers for professional development

Tedford, Douglas H. 01 January 2008 (has links)
This qualitative study examined Internet usage by Guatemalan English teachers in the rural, indigenous community of San Lucas Toliman, to improve enrollments and persistence in online teacher professional development programs promoted by the Fundacion Rigoberta Menchu Tum. Woolcock's concepts of bonding, bridging and linking social capital were united with Rogers's theory of perceived attributes to ascertain why only 5 of 34 teachers completed free online coursework. Research questions addressed teacher concerns about using the Internet, teacher satisfaction with Internet resources, and social influences upon Internet usage. The participatory rural appraisal (PRA) method was employed using a culturally-sensitive native speaker to interview 20 teachers selected in a purposive sample. In accordance with PRA analysis procedures, representative interview statements were sorted, prioritized and discussed by a team of 42 community educators to generate findings. Findings indicated that interest in engaging the Internet and receiving specialized introductory support (bridging social capital) in groups (bonding social capital) was high. Findings also indicated that salary level (linking social capital) and family time demands (bonding social capital) were barriers to attending a community technology center or Internet cafe. Findings reinforced the community's support for the design of online coursework leading to salary points and college credits. This study has positive social change implications by demonstrating how organizations can promote community-driven research collaborations to facilitate teacher Internet usage in San Lucas Toliman, and could be replicated in other remote sectors of the developing world.
494

Soil-Pile, Pile Group Foundations and Pipeline Systems Interaction Behavior Extending Saturated and Unsaturated Soil Mechanics

Al-Khazaali, Mohammed 25 February 2019 (has links)
Rapid growth in population along with positive trends in global economy over the past several decades has significantly contributed to an increased demand for various infrastructure needs worldwide. For this reason, the focus of this thesis has been directed towards extending the mechanics of unsaturated soils, which is an emerging geotechnical engineering field to investigate the behavior of two key infrastructure systems, namely pile foundations and energy pipeline systems. The mechanism of soil-pile foundations and soil-pipeline systems interaction behavior has several similarities. Both these infrastructure facilities require comprehensive understanding of the soil-structure interaction mechanism. Reliable estimation of mechanical properties of both the soil and the soil-structure interface is required for the rational interpretation the load-displacement behavior of pile foundations and pipeline systems. Currently, the design of systems is predominantly based on design codes and guidelines that use empirical procedures or employ the principles of saturated soil mechanics. In many scenarios, pile foundations extend either totally or partly in unsaturated soils as the groundwater table level in many regions is at a greater depth. Such scenarios are commonly encountered in semi-arid and arid regions of the world. In addition, pipeline systems are typically buried at shallow depths in unsaturated soil strata, which are susceptible to wetting and drying, freezing and thawing cycles or both, due to seasonal environmental changes. Capillary stress or matric suction in the unsaturated zone increases the effective stress contribution towards the shear strength and stiffness of soil and soil-structure interface. Extending saturated soil mechanics to design or analyze such structures may lead to erroneous estimation of pile foundation carrying capacity or loads transferred on pipeline body from the surrounding unsaturated soil. Experimental, analytical and numerical investigations were undertaken to study the behavior of single pile, pile group, and pipeline systems in saturated and unsaturated sands under static loading. The experimental program includes 40 single model pile and 2×2 pile group, and six prototype pipeline tests under saturated and unsaturated condition. The results of the experimental studies suggest that matric suction has significant contribution towards the mechanical behavior of both pile foundation and pipeline system. The axial load carrying capacity of single pile and pile group increased approximately 2 to 2.5 times and the settlement reduced significantly compared to saturated condition. The influence of matric suction towards a single pile is significantly different in comparison to pile group behavior. The cumulative influence of matric suction and stress overlap of pile group behavior in sandy soils result in erroneous estimation of pile group capacity, if principles of saturated soil mechanics are extended. Group action plays major role in changing the moisture regime under the pile group leading to incompatible stress state condition in comparison to single pile behavior. On the other hand, the peak axial load on the pipe is almost 2.5 folds greater in unsaturated sand that undergoes much less displacement in comparison to saturated condition. Such an increase in the external axial forces may jeopardize the integrity of energy pipeline systems and requires careful reevaluation of existing design models extending the principles of unsaturated soil mechanics. Two analytical design models to estimate the axial force exerted on pipeline body were proposed. The proposed models take account of matric suction effect and soil dilatancy and provide smooth transition from unsaturated to saturated condition. These models were developed since measurement of the unsaturated soil and interface shear strength and stiffness properties need extensive equipment that require services of trained professional, which are expensive and time consuming. The models utilize the saturated soil shear strength parameters and soil-water characteristic curve (SWCC) to predict the mechanical behavior of the structure in saturated and unsaturated cohesionless soils. The prototype pipeline experimental results were used to verify the proposed models. The predicted axial force on pipeline using the proposed models agrees well with the measured behavior under both saturated and unsaturated conditions. Moreover, numerical techniques were proposed to investigate the behavior of pile foundation and pipeline system in saturated and unsaturated sand. The proposed methodology can be used with different commercially available software programs. Two finite element analysis programs were used in this study; namely, PLAXIS 2D (2012) to simulate soil-pile foundation behavior and SIGMA/W (2012) to simulate soil-pipeline system behavior. The proposed techniques require the information of unsaturated shear strength and stiffness, which can be derived from saturated soil properties and the SWCC. The model was verified using pile and pipeline test results from this study and other research studies from the published literature. There is a good agreement between the measured behavior and the predicted behavior for both the saturated and unsaturated conditions. The methodology was further extended to investigate the behavior of rigid and flexible pipelines buried in Indian Head till (IHT) during nearby soil excavation activity. The simulation results suggest that excavation can be extended safely without excessive deformation to several meters without the need for supporting system under unsaturated condition. The studies summarized in the thesis provide evidence that the principles of saturated soil mechanics underestimate the pile foundations carrying capacity as well as the axial force exerted on pipelines in unsaturated soils. Such approaches lead to both uneconomical pile foundation and unsafe pipeline systems designs. For this reason, the pile and pile group carrying capacity and pipeline axial force should be estimated taking into account the influence of matric suction as well as the dilatancy of the compacted sand. The experimental studies, testing techniques along with the analyses of test results and the proposed analytical and numerical models are useful for better understanding the pile foundation and buried pipeline behaviors under both saturated and unsaturated conditions. The proposed analytical and finite element models are promising for applying the mechanics of unsaturated soils into conventional geotechnical engineering practice using simple methods.
495

慈善基金會的成功、策略和公眾參與: 中國個案研究. / Success, strategy and public participation of philanthropic foundations: case studies in Mainland China / CUHK electronic theses & dissertations collection / Ci shan ji jin hui de cheng gong, ce lüe he gong zhong can yu: Zhongguo ge an yan jiu.

January 2007 (has links)
Finally, this thesis put forward specific recommendations in relation to social welfare policies, social work practice, organizational capacity building, organizational performance assessment and the future areas for research on philanthropic foundations. / The purpose of this research is to describe and discuss the magnitude of success, use of strategies and extent of public participation in philanthropic foundations under the socialist system of China. It also analyzes how the effectiveness of these philanthropic foundations is related to their selected strategies and their extent of public participation. / The research also found that public participation was an essential value in the philanthropic foundations. Public participation was a tactic to obtain resources, and to realize success in the organization. However, empowerment of the service users had not been given enough attention. Meanwhile, the participants in the philanthropic foundations could be classified as individuals and legal entities, administrative units, public organizations and quasi-governmental organizations. The mode of participation varied from the "one-way model", the "participatory model" and the "decision-making model". Accordingly, four models of participation were identified. / The research found that the successful philanthropic foundations had differing manifestations and weights in variables pertaining to "objectives", "degree of satisfaction", "legitimacy" and "resource input". Whilst the variables were related to each others, the weight for each variable differed in the studied cases. Classified in terms of the weight of the variables, there were four models among the successful philanthropic foundations, namely, the "equilibrium model", the "satisfying model", the "legitimate model" and the "sustainable model". / The research further found that there was correlations among the manifestation of success, strategic orientation, and mode of participation. The case background is related to certain manifestation of success, strategy and mode of public participation, constructing four reaction patterns. These reaction patterns are premised on "organization", "resources", "need", and "government", producing different relationships among "success", "strategy" and "public participation". / The study identified the functional dimension (philanthropic versus charity) and the instrumental dimension (market versus government action), from which five different strategies were derived from the philanthropic foundations studied. They were the "strong market orientation", the "compromising orientation", the "weak market orientation", the "mutuality orientation" and the "governmental orientation". / This research is a case study of 7 legally registered philanthropic foundations supported by non-governmental funds. Twenty senior management staffs working in the 7 philanthropic foundations participated in the in-depth interviews. The samples were selected from various departments under different administrative levels in Mainland China, including the central government level, the provincial level and the municipal level, and taking into account the economic strength of the regions. All the selected cases included philanthropic services for children, and have been operating for more than 5 years. These homogeneous cases are to a certain extent typical cases. / 陳津利. / 呈交日期: 2005年6月. / 論文(哲學博士)--香港中文大學, 2005. / 參考文獻(p. 406-426). / Cheng jiao ri qi: 2005 nian 6 yue. / Source: Dissertation Abstracts International, Volume: 67-01, Section: A, page: 0336. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / School code: 1307. / Lun wen (zhe xue bo shi)--Xianggang Zhong wen da xue, 2005. / Can kao wen xian (p. 406-426). / Chen Jinli.
496

Empowering adolescents: A multiple case study of U.S. Montessori high schools

LaRue, Wendy J. 01 January 2010 (has links)
The standards-based, teach-and-test methods that have come to proliferate secondary education since the inception of the No Child Left Behind Act (NCLB) fail to adequately prepare students for higher education and employment. This system lacks opportunities for developing 21st century skills such as higher-level thinking, problem solving, and group dynamics, as well as opportunities for fostering spiritual growth and personal development. This problem impacts graduates of U.S. high schools because they are unprepared for higher education and the 21st century workplace. Using qualitative multiple case study methodology, this study examined five U.S. Montessori high schools through the lens of cultural-historical activity theory. Interview and blog-based focus group responses and document data were coded line-by-line using predetermined categories and codes as well as open coding. The coded data were analyzed by individual case and then collectively. Findings revealed that education in these settings addressed all areas of development and fostered 21st century skills. Some characteristics that typify Montessori education at lower levels, such as multi-age classes and the prepared environment, played less significant or different roles in the high school programs. Characteristics that were prominent across the cases included use of place-based, experiential learning; building of caring, family-like staff/student relationships; and emphasis on social development. Implications for social change within the Montessori community include informing practice at existing schools and development of teacher education programs. In the broader education community, the consistency in program emphasis, despite diverse school circumstances, suggests a Montessori approach may facilitate social change by inspiring a fresh approach to school reform in high schools.
497

Seismically Induced Tilting Potential Of Shallow Mats On Fine Soils

Yilmaz, Mustafa Tolga 01 September 2004 (has links) (PDF)
Occurrence of displacements of shallow mat foundations resting on saturated silt-clay mixtures were reported in Mexico City during 1985 Mexico Earthquake, and in Adapazari during 1999 Kocaeli (izmit) Earthquake. Soft surface soils, shallow ground water, limited foundation embedments and deep alluvial deposits were the common features pertaining to such foundation displacements in either case. Experience shows, while uniform foundation settlements, even when excessive, do not limit post earthquake serviceability of building structures, tilting is particularly problematic. In this study, a simplified methodology is developed to estimate the seismically induced irrecoverable tilting potential of shallow mats on fine saturated soils. The undrained shear and deformation behavior of silt-clay mixtures encountered at the Adapazari sites with significant foundation displacements are investigated through a series of standard and rapid monotonic, and stress-controlled cyclic triaxial tests conducted over anisotropically consolidated natural soil samples. Test results show that, while the shear strength of these soils do not significantly degrade under means of loading comparable to that of Kocaeli earthquake, their plastic strain accumulation characteristics critically depend on the mode of loading as well as the relative levels of applied load with regard to the monotonic strength. Based on the results of laboratory tests, the response of nonlinear soil-foundation-structure system is reduced to a single-degree-of-freedom oscillator with elastic-perfectly plastic behavior. The natural period of the system is expressed by simplified soil-structure-interaction equations. Pseudo-static yield acceleration, which is required to initiate the foundation bearing capacity failure when applied to the structural mass, is estimated by the finite-element method. Eventually, the tilting potential of the foundations is estimated utilizing inelastic response of the nonlinear oscillator. Response of the deep alluvium sites, which involves velocity pulses with periods consistent with the fundamental site period, is significant in determination of inelastic response of low bearing capacity systems. Predictive capability of the methodology developed is tested with actual case data. The methodology is observed to predict irrecoverable tilting potential of foundations consistent with the observations, except for the cases with low seismic bearing capacity. Deviations are explained considering the sensitivity of low-strength systems to asymmetrical behavior and uncertainties involved in seismic demand.
498

New mechanism-based design approaches for spudcan foundations in clay

Hossain, Muhammad Shazzad January 2009 (has links)
[Truncated abstract] Three-legged mobile jack-up rigs supported on spudcan foundations are used to perform most offshore drilling in shallow to moderate water depths, and are now capable of operating in water depths up to 130 m. With the gradual move towards heavier rigs in deeper water, and continuing high accident rates during preloading of the spudcan foundations, appraisal of the performance and safety of jack-up rigs has become increasingly important. A crucial aspect of this is to improve understanding of the mechanisms of soil flow around spudcan foundations undergoing continuous large penetration, and to provide accurate estimates of spudcan penetration resistance, avoiding excessive conservatism. Spudcan foundations undergo progressive penetration during preloading, contrasting with onshore practice where a footing is placed at the base of a pre-excavated hole or trench. However, spudcan penetration is generally assessed within the framework used for onshore foundations, considering the bearing resistance of spudcans pre-placed at different depths within the soil profile. The lack of accurate design approaches that take proper account of the nature of spudcan continuous penetration, which is particularly important in layered soil profiles, is an important factor in the high rate of accidents. ... It was found that when a spudcan penetrated into single layer clay, there were three distinct penetration mechanisms: during initial penetration, soil flow extended upwards to the surface leading to surface heave and formation of a cavity above the spudcan; with further penetration, soil began to flow back gradually onto the top of the spudcan; during deep penetration, soil back-flow continued to occur while the initial cavity remained unchanged. For spudcan penetration in stiff-over-soft clay, four interesting aspects of the soil flow mechanisms were identified: (a) vertically downward motion of the soil and consequent deformation of the layer interface; (b) trapping of the stronger material beneath the spudcan, with this material being carried down into the underlying soft layer; (c) delayed back-flow of soil around the spudcan into the cavity formed above the spudcan; (d) eventual localised flow around the embedded spudcan, surrounded by strong soil. At some stage during continuous spudcan penetration, the soil starts to flow back into the cavity above the spudcan. The resulting back-flow provides a seal above the penetrating spudcan and limits the cavity depth. It was shown that the current offshore design guidelines are based on the wrong criterion for when back-flow occurs. New design charts with robust expressions were developed to estimate the point of back-flow and hence the cavity depth above the installed spudcan. Load-penetration responses were presented in terms of normalised soil properties and geometry factors for both single layer and two-layer clay profiles, taking full account of the observed flow mechanisms. Further, guidelines were suggested to evaluate the likelihood and severity of spudcan punch-through failure in layered clays. Finally, the effect of strain-rate and strain-softening was examined, in an attempt to model real soil behaviour more closely. Adjustment factors were proposed to modify the design approaches developed on the basis of ideal elastic-perfectly plastic soil behaviour.
499

Estudo de caso da política pública de criação da Fundação Hospital Adriano Jorge: uma avaliação da eficácia da autonomia administrativo-financeira

Zogahib, André Luiz Nunes January 2008 (has links)
Submitted by Rafaela Moraes (rafaela.moraes@fgv.br) on 2016-09-06T13:15:03Z No. of bitstreams: 1 Binder1.pdf: 1026779 bytes, checksum: 9f22fd53c9b47a7ad64d8477b6c0756f (MD5) / Approved for entry into archive by Rafaela Moraes (rafaela.moraes@fgv.br) on 2016-09-06T13:16:12Z (GMT) No. of bitstreams: 1 Binder1.pdf: 1026779 bytes, checksum: 9f22fd53c9b47a7ad64d8477b6c0756f (MD5) / Approved for entry into archive by Rafaela Moraes (rafaela.moraes@fgv.br) on 2016-09-06T13:17:05Z (GMT) No. of bitstreams: 1 Binder1.pdf: 1026779 bytes, checksum: 9f22fd53c9b47a7ad64d8477b6c0756f (MD5) / Made available in DSpace on 2016-09-06T13:17:54Z (GMT). No. of bitstreams: 1 Binder1.pdf: 1026779 bytes, checksum: 9f22fd53c9b47a7ad64d8477b6c0756f (MD5) Previous issue date: 2008 / Este trabalho evidencia, no estudo de caso da criação de uma fundação pública de saúde no Estado do Amazonas, a Fundação Hospital Adriano Jorge – FHAJ, como as descentralizações na saúde pública amazonense tendem a ocorrer. Assim, avaliou-se a política pública de criação da FHAJ, no intuito de identificar se os resultados esperados em sua concepção, ganho de autonomia administrativo-financeira, foram efetivamente alcançados. Sobre a luz dos conceitos de políticas públicas, de ciclo de política pública e de avaliação de políticas públicas abordados por diversos autores, além das proposituras de descentralização sugeridas pelo Sistema Único de Saúde e pelo conceito de Fundações Públicas, buscou-se verificar se houve um aumento dos serviços prestados ou melhora de sua qualidade. Desta forma, evidenciou-se, também, variáveis que pudessem expressar o ganho, a perda ou a manutenção do nível de autonomia administrativo-financeira do Hospital Geral Adriano Jorge, após sua transformação em Fundação Pública. / This work proposes to present the case of the public policy for creation of a public health foundation in the state of Amazonas, the Adriano Jorge Hospital Foundation – FHAJ. Thus, the aforementioned public policy was evaluated, attempting to identify whether the results expected at its conception – increase in administrative-financial autonomy – effectively came about. Preliminarily, we identified the concepts of public policy, the cycle of public policy and of evaluation of public policies broached by several authors, besides evidencing the propositions of decentralization suggested by the Single Health System and by the concept of Public Foundations. The budget and administrative results from 2002-2007 were shown, and a tendency to decrease was verified, which accentuated in the last year, indicating a possible excessive administrative-financial dependence.
500

Estudo comparativo entro o SPT, a prova de carga sobre placas e o ensaio pressiométrico, aplicado a fundações superficiais em solo arenoso - resultados preliminares. / Comparative study between the SPT, the load test on plates and the pressiometric test, applied to surface foundations in sandy soil - preliminary results.

BEZERRA, Sosthemar Pedrosa. 10 November 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-11-10T13:23:14Z No. of bitstreams: 1 SOSTHEMAR PEDROSA BEZERRA - DISSERTAÇÃO PPGECA 1990..pdf: 26819503 bytes, checksum: a420d17888b6840c1a3392d4b2d31be4 (MD5) / Made available in DSpace on 2018-11-10T13:23:14Z (GMT). No. of bitstreams: 1 SOSTHEMAR PEDROSA BEZERRA - DISSERTAÇÃO PPGECA 1990..pdf: 26819503 bytes, checksum: a420d17888b6840c1a3392d4b2d31be4 (MD5) Previous issue date: 1990-04 / CNPq / Capes / Este trabalho apresenta um estudo comparativo da aplicação do SPT, da prova de carga sobre placas e do ensaio pressiométrico em projetos de fundações superficiais em solos arenosos, com o objetivo de mostrar a possibilidade do uso alternativo do pressiômetro de Briaud, em substituição à prova de carga e ao SPT, e suas vantagens. O campo experimental é um subsolo areno-siltoso situado na zona urbana de Campina Grande-PB, no qual executa-se sondagensSPT, provas de carga sobre placas apoiadas na superfície, provas de carga, em profundidade - com carregamentos verticais e horizontais - e ensaios pressiométricos em furos verticais e horizontais, além da verificação da densidade in situ e do teor de umidade natural, todos em um perfil com 1,90 m de profundidade. Comenta-se as vantagens e desvantagens dos ensaios realizados e verifica-se que a técnica pressiométrica - via pressiômetro de Briaud - apresenta muitas vantagens sobre a prova de carga e, ainda, que o SPT não deve, isoladamente, ser aplicado para estimar a capacidade de carga de fundações superficiais. Finalmente, conclui-se que os resultados obtidos evidenciam a possibilidade de aplicação do pressiômetro de Briaud, na determinação da capacidade de carga de fundações superficiais, em solos arenosos. / This paper presents a comparative study of the application of the 5PT, of the plate load test, and of the pressuremeter test on shallow foundations projects in sandy soils, aiming at showing the possibility of alternative usage of the BRIAUD pressuremeter test as a substitute to both the plate load test and the 5PT, and their advantages. The experimental field is a silty-sand subsoil situated on the urban área of Campina Grande, Paraíba, where we carry out SPT soundings , plate load tests supported on the surface, plate load tests in depth - with vertical and horizontal loads - and pressuremeter tests in vertical and horizontal holes, besides the verification of the natural unit weight and the natural water content, ali of them in a profile of 1.90 meters deep. Following, we discuss the advantages and disadvantages of the experiments done and we get to know that the pressuremeter technique - throug the BRIAUD pressuremeter - offer many advantages concerning plate load tests; and, in addition, that the 5PT should not, in isolation, be applied to estimate the ultimate bearing capacity of shallow foundations. At the end, we conclude that the results reached give us proof of reasons to believe of the possibility of application of the BRIAUD pressuremeter in determining the bearing capacity of shallow foundations in sandy soils.

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