Aerodynamics of Highway Sign Structures: From Laboratory Tests and Field Monitoring to Structural Design Guidelines

2020 ◽  
Vol 146 (11) ◽  
pp. 04020233
Author(s):  
Michael Heisel ◽  
Carly Daugherty ◽  
Nicole Finley ◽  
Lauren Linderman ◽  
Dominik Schillinger ◽  
...  
Keyword(s):  
Structural Design ◽  
Laboratory Tests ◽  
Design Guidelines ◽  
Field Monitoring

Development of Structural Design Guidelines for Porous Asphalt Pavement

2018 ◽  
Vol 2672 (40) ◽  
pp. 197-206 ◽  
Author(s):  
Kevin D. Hall ◽  
Charles W. Schwartz
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Field Performance ◽  
Design Guidelines ◽  
Empirical Approach ◽  
Asphalt Pavements ◽  
Design Parameters ◽  
Extensive Literature ◽  
Porous Asphalt ◽  
Design Procedures

Porous asphalt pavements allow designers to introduce more sustainability into projects and lessen their environmental impact. Current design procedures are based primarily on hydrologic considerations; comparatively little attention has been paid to their structural design aspects. As their use grows, a design procedure and representative material structural properties are needed to ensure that porous pavements do not deteriorate excessively under traffic loads. The objective of this project was to develop a simple, easy to apply design procedure for the structural design of porous asphalt pavements. Two methodologies were considered for such a structural design procedure: ( a) the 1993 AASHTO Pavement Design Guide empirical approach, and ( b) the mechanistic–empirical approach employed by the AASHTOWare Pavement ME Design software. A multifactor evaluation indicated the empirical 1993 AASHTO design procedure to be the most appropriate platform at this time. It is noted, however, that both design procedures lack validation of porous asphalt pavements against field performance. AASHTO design parameters and associated material characteristics are recommended, based on an extensive literature review. For “thin” open-graded base structures (12 in. or less), the AASHTO procedure is performed as published in the 1993 Guide. For “thick” base structures (>12 in.), the base/subgrade combination is considered a composite system which supports the porous asphalt layer; an equivalent deflection-based approach is described to estimate the composite resilient modulus of the foundation system, prior to applying the 1993 AASHTO design procedure.

Construction of structural design guidelines for vacuum vessels and other components

1998 ◽  
Vol 41 (1-4) ◽  
pp. 305-312 ◽  
Author(s):  
K. Miya ◽  
A. Kobayashi ◽  
K. Koizumi ◽  
K. Hada ◽  
T. Shimakawa
Keyword(s):  
Structural Design ◽  
Design Guidelines

scholarly journals Elliptical hollow section T and X connections

2012 ◽  
Vol 39 (8) ◽  
pp. 925-936 ◽  
Author(s):  
Tarana Haque ◽  
Jeffrey A. Packer
Keyword(s):  
Construction Industry ◽  
Structural Design ◽  
Failure Modes ◽  
Design Method ◽  
Design Guidelines ◽  
Preliminary Design ◽  
Hollow Section ◽  
Steel Shape ◽  
Circular Hollow Section ◽  
Angle Orientation

Elliptical hollow sections (EHS) are the newest steel shape to have emerged in the construction industry. They have been incorporated in a variety of structures around the world, including Canada, without structural design guidelines. To date, EHS are completely absent from Canadian codes and guides. A possible application of EHS is within truss-systems and, as such, a research project has been undertaken to investigate the behaviour of EHS-to-EHS welded connections. Twelve T and X connection tests have been performed to study the effect of connection angle, orientation type, and loading sense. Two methods to predict connection capacities and failure modes are investigated: an equivalent circular hollow section (CHS) approach and an equivalent rectangular hollow section (RHS) approach. The equivalent RHS approach proved to be more successful at capturing the actual failure mode of welded EHS-to-EHS connections and is therefore recommended at this time as a preliminary design method for EHS truss-type connections.

scholarly journals Large-Scale Model Testing of High-Speed Railway Subgrade under Freeze-Thaw and Precipitation Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Shasha Zhang ◽  
Yantao Wang ◽  
Fei Xiao ◽  
Weizhi Chen
Keyword(s):  
Moisture Content ◽  
High Speed ◽  
Laboratory Tests ◽  
Large Scale ◽  
Saline Soil ◽  
Field Monitoring ◽  
Coarse Grained ◽  
Scale Model ◽  
High Speed Railway ◽  
Freeze Thaw

To determine whether coarse-grained saline soil meets the deformation requirements of the DY high-speed railway subgrade, a study was conducted by a combination of field-monitoring and laboratory tests. First, several temperature sensors were buried vertically in the ground of a typical section, and the temperature at different depths was monitored for nearly one year and analysed dynamically. It was determined that a depth of 4.8 m can be set as the constant-temperature layer. Then, based on the field-monitoring results, laboratory tests were carried out on a large-scale subgrade model under freeze-thaw and precipitation conditions. The change of temperature, moisture content, and soil deformation of the subgrade under long-term freeze-thaw and precipitation conditions were obtained. The results show that the temperature changes periodically with a V shape during the entire cycle. Twenty centimetres below the top surface is the sensitive depth of the sample, and salinity has little effect on temperature change. In the process of cycles, the average moisture content of soils with higher salinity is about 0.5% lower than that of soils with lower salinity. After nine freeze-thaw cycles, the sample finally shows dissolved settlement deformation. Precipitation mainly affects the deformation of the sample; however, the influence on salt-expansion and frost-heave deformation is less significant. Finally, by predicting the deformation of coarse saline soil, it is proven that the soil can meet the deformation requirements of high-speed railway foundations.

scholarly journals The Effect of Service Installations on Structural Integrity of Slabs in Buildings

2010 ◽  
Vol 33 (1) ◽  
pp. 18-28
Author(s):  
Ladslaus Lwambuka
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Structural Design ◽  
Design Guidelines ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Structural Element ◽  
Load Bearing Capacity ◽  
Cross Sectional ◽  
Load Bearing

In building construction industry service installations, usually housed in conduit pipes, are commonly mounted inside reinforced concrete structural elements. This practice is adopted to attain aesthetical outlook at both interior and exterior surfaces of the buildings. Depending on the extent of service installations, the cross sectional area of the load bearing structural member is substantially reduced. However, the current structural design guidelines have no provision to accommodate the extent to which the existence of conduit pipes impairs the load bearing capacity of the structural element though reduced cross sectional area. This study has attempted to address this gap in structural design ofbuildings; it involves assessing the current design practice of considering a structural element as a full solid body and comparing its ultimate load bearing capacity with the ones containing the conduit pipes. The study findings are based on test results from laboratory experiments on reinforced concrete slab models with varying intensity of conduit pipeinstallations as commonly practiced on construction sites. Recommendations are put forth when and how to consider the reduced load bearing capacity through the existence of service installations as part of structural engineering designs.

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