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Showing 1 to 20 of 62 for “"abutments"”.
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Scour at bridge piers and abutments
In this thesis several of the formulae that have been put forward to predict scour are examined and some of their limitations pointed out in an attempt to clarify some of the research work that has been done on scour. The formulae are applied to two known bridge failures and their accuracy in those …
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Experimental and Analytical Investigations of Piles and Abutments of Integral Bridges
… bridges crates concerns for the piles and the abutments of integral bridges because the abutments and the piles are subjected to temperature-induced cyclic lateral loads. As temperatures change daily and seasonally, the lengths of integral bridges increase and decrease, pushing the abutment …
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Seismic performance assessment of quasi-isolated highway bridges with seat-type abutments
… quasi-isolated highway bridges with seat-type abutments, validate the current design strategy, and provide recommendations for improving the bridge seismic performance. To encompass common configurations of quasi-isolated highway bridges, a suite of prototype bridges with variations in the span …
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Effects of sterilization, conditioning, and thermal aging on the retention of zirconia hybrid abutments
… on the retention strength of two-piece zirconia abutments. A total of 128 stock zirconia abutments were divided into 4 groups, each including 32 abutments. The groups were categorized based on the conditioning parameters used: Air-abrasion with (A) 50 µm alumina particles at 1.0 bar pressure, (B) …
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The comparison of tensile strength of polycarboxylate cement among different surfaces of implant custom abutments
… lithium disilicate crowns and implant abutments cemented with polycarboxylate cement. Material & Methods A master cast of a maxillary right central incisor single implant restoration from a clinical case was utilized to fabricate five samples of each of five unique abutment types: …
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Analysis of vertical rectangular abutments of a skewed rigid frame bridge for bending and extension
… themselves. Development of the equations for the abutments has been independent of the angle of skew. Therefore, they may be used with any solution or this type tor a slab of like material and same length knee, skewed at any angle. As a special case, a right rigid-frame bridge could also be …
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Marginal Discrepancy of Components Utilized for Implant Framework Construction
… ( castable plastic patterns, premachined gold abutments, premachined titanium abutments and CAD-CAM custom premachined titanium abutments) were evaluated. Five castable plastic patterns and five premachined gold abutme~ts from each of two manufacturers, five premachined titanium abutments and …
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Combined abutment and contraction scour in compound channels for extreme flood events
… carried out in compound channels, simulating abutments set back from the main channel. Spill-through abutments were used in the live-bed scour regime, and both spill-through and wing-wall abutments were used in the clear-water regime. In addition, to better understand the effect of contraction …
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Evaluation of implant restoration retention on various custom abutment materials and surfaces
… design and manufacturing of 25 implant custom abutments planned for cement-retained restorations. Although all 25 implant custom abutments were designed to be identical in contour, each group of five abutments was fabricated from different materials or had different surface characteristics. The …
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An Investigation of Heat Transfer to the Implant-Bone Interface and Marginal Gingiva During Preparation of Implant Abutments in the Mouth: in vitro study
The aim of the present study was to assess in vitro the heat generated within the implant body when preparing implant abutment of the Osstem implant system to estimate the potential risk of tissue and bone damage of individual abutment preparation. The domestic Osstem implants(Osstem dental …
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Probabilistic Seismic Assessment of Structure, Foundation, and Soil Interacting Systems
… Soil-Structure Interaction (SSI) are tried: (a) Abutments and foundations are assumed to be fixed, (b) Conventional lumped spring approaches are adopted to model abutments and foundations, (c) Lumped springs for abutments and foundations are estimated from Finite Element (FE) analysis of …
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Numerical modelling of local scour in rivers using fluent 6.2
… to the stream flow such as bridge piers and abutments and other hydraulic structures alter flow patterns causing local scouring and deposition. Excessive scour undermines the foundations of bridges and other fluvial structures which may ultimately cause their collapse. Reliable methods are …
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Seismic Analysis and Response of Highway Bridges with Hybrid Isolation
… In this technique isolators are only used at the abutments, and monolithic or pinned connections remain at the piers. Both full and hybrid isolation can be shown to reduce the demand on critical members such as columns and foundations, but hybrid isolation also reduces superstructure displacements …
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Assessment of HEC-18 scour equations for bottomless culverts based on Kansas field data
… main causes of bridge failure is scour at the abutments or piers. Scour is caused by increased velocities of water through bridge openings. Sediment is carried away from the foundations by high flows causing the bridge to become unstable and possibly collapse. Bottomless culverts have become an …
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Mechanical Behavior of Posterior Implant Supported Restorations
… crown designs, hybrid-abutment-crowns and hybrid-abutments with separate crowns. Thirty-two implants were embedded perpendicularly in an auto-polymerizing resin. Thirty-two implant-supported restorations simulating a maxillary first premolar were designed and milled using a CAD/CAM system. These …
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IMPACT OF SOIL-STRUCTURE INTERACTION ON SEISMIC BEHAVIOUR OF INTEGRAL ABUTMENT BRIDGES
… transport networks, where the bridge deck and abutments are rigidly connected (i.e., monolithic connection). The rigid connection between the main structural elements of the integral abutment bridges (IAB) (i.e., the deckabutments- footings) has increased the interaction of the bridge with the …
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