Excavation
Mostrando 1-12 de 101 artigos, teses e dissertações.
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1. AMAZÔNIA BRASILEIRA, CELEIRO DO MUNDO: CIÊNCIA, AGRICULTURA E ECOLOGIA NO INSTITUTO AGRONÔMICO DO NORTE NOS ANOS 1940 E 1950
Resumo O artigo analisa as pesquisas científicas realizadas no Instituto Agronômico do Norte (IAN), instituição criada pela política desenvolvimentista do governo brasileiro para a utilização agrícola da Amazônia nas décadas de 1940 e 1950. Discutimos especialmente as pesquisas relacionadas à chamada “teoria do ecossistema florestal”, desenvol
Rev. Hist. (São Paulo). Publicado em: 09/12/2019
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2. Analytical solution of circular tunnel in elastic-viscoplastic rock mass
Abstract This paper deals with a deep circular tunnel excavated in infinite homogeneous and isotropic elasto-viscoplastic rock mass subjected to a hydrostatic initial stresses. The tunnel is divided into the initial plastic, viscoplastic, and elastic zones. By combining the generalized Bingham model with Mohr-Coulomb yield criteria, analytical solutions of t
Lat. Am. j. solids struct.. Publicado em: 29/07/2019
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3. Mechanical Mechanism Analysis and Influencing Factors of Subway Cross Passage Construction
Abstract The construction of the cross passage changes the main tunnels segment from a complete cylindrical structure to a notched unstable stressed structure. Thus, the overall force (bending and shearing) performance of the main tunnels is considerably decreased. The excavation of the cross passage also destroys the stability of the original soil layer and
Lat. Am. j. solids struct.. Publicado em: 01/07/2019
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4. Scale effect on mean pressures: study of two reduced models of a ski jump spillway
RESUMO O vertedouro tipo salto esqui está presente em grandes barragens brasileiras. Após a operação desse tipo de vertedouro se origina uma fossa de erosão a jusante, que complementa o sistema de dissipação de energia, pois o jato é amortecido pelo colchão d’água. À medida que a escavação da fossa de erosão evolui, sua forma se altera, haven
RBRH. Publicado em: 01/07/2019
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5. High pressure abrasive water jet for excavation purpose: a tridimensional approach for cutting strategy
Abstract High pressure abrasive water jets (HPAWJ) are an emergent excavation technology. Despite being used for several applications since the nineteenth century, it is only in recent decades that this excavation purpose has been considered. This is the result of evolution in high pressure pump technology and parameter investigation. Special highlight shoul
REM, Int. Eng. J.. Publicado em: 2019-03
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6. Development and application of a flexible numerical model to evaluate the safety of room-and-pillar mines
Abstract The design of room-and-pillar mines relies on the correct estimation of the safety indicator of the underground structures formed by the excavation of drifts. Thus, the study of the geomechanical behavior is of vital importance. The mathematical models play an important role in the identification of problematic areas and allows different configurati
REM, Int. Eng. J.. Publicado em: 2019-03
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7. Use of PVC pipes to determine bulk density for irrigation management
RESUMO A irrigação tem grande importância para a produção de alimentos, sendo responsável por consumir grande parcela da água usada nas atividades humanas. Isto torna fundamental o manejo racional do uso da água. Para tal, a determinação da densidade do solo é importante e precisa ser realizada de forma simples e menos honerosa possível, mantendo
Rev. Ciênc. Agron.. Publicado em: 2019-03
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8. Ultrassonografia do nervo óptico no modo A para o diagnóstico do glaucoma
Resumo Objetivos: Determinar se a medida do diâmetro horizontal ou refletividade do nervo óptico retrobulbar no modo A apresenta correlação com a relação da escavação pelo diâmetro do nervo óptico no glaucoma, considerando: a correlação das medidas, a sensibilidade e especificidade entre os métodos e qual a medida tem maior sensibilidade e espe
Rev. bras.oftalmol.. Publicado em: 2019-02
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9. Risk evaluation in tunneling excavation methods
Abstract Risk management is of paramount importance for the success of tunneling works and it is linked to the main excavation methods used: the Conventional Excavation Method (CEM) and the Tunnel Boring Machine Method (TBM). Considering the importance of the “Safety and Health” criterion for the choice of the excavation method, the fact that this criter
REM, Int. Eng. J.. Publicado em: 2018-07
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10. Water jet tunneling: a theoretical advanced rate evaluation
Abstract Tunnel Boring Machines play an important role in the underground infrastructure execution of modern cities. They weigh thousands of tons and measure hundreds of meters besides utilizing high powered energy in the excavation process. Although being well established, they are based on a last century design approach and they are not compatible anymore
REM, Int. Eng. J.. Publicado em: 2018-04
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11. New concept of tunnel boring machine: high performance using water jet and diamond wire as rock cutting technology
Abstract Tunnel boring machines are important tools in underground infrastructure projects. Although being well established equipment, these machinesare based on designsof more than 60 years ago and are characterized by big dimensions, enormous weight and high power consumption. Commercial aspects should be noted too. The model adopted by the TBM industry re
REM, Int. Eng. J.. Publicado em: 2018-03
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12. Comparing blast-induced ground vibration models using ANN and empirical geomechanical relationships
Abstract Blasting remains as an economical and reliable excavation technique, but there are some environmental shortcomings such as the control of blast-induced vibration. The impacts of vibration over surrounding communities in a blast area have been investigated for decades and researchers have been using a myriad of empirical predictive attenuation equati
REM, Int. Eng. J.. Publicado em: 2018-03