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.

scholarly journals STRUCTURAL DESIGN PROCEDURES FOR CONCRETE ARMOUR UNITS

1984 ◽  
Vol 1 (19) ◽  
pp. 172 ◽  
Author(s):  
Kevin R. Hall ◽  
W.F. Baird ◽  
D.J. Turcke
Keyword(s):  
Structural Design ◽  
Rational Design ◽  
Structural Integrity ◽  
Design Procedure ◽  
Analytical Techniques ◽  
Structural Performance ◽  
Design Procedures ◽  
Design Loads ◽  
Resultant Stress ◽  
Hydraulic Stability

A rational design procedure for rubblemound breakwater protection which will ensure both the structural integrity and hydraulic stability of individual concrete armour units and the overall armour system is presented. The procedure involves new experimental techniques for measuring strains in model concrete armour units in a hydraulic model of a breakwater subjected to simulated prototype wave attack and analytical techniques for determining equivalent prototype loads on units. Selected design loads are used to define the resultant stress distribution to allow the designer to take the necessary measures to ensure the structural performance of the unit in a breakwater environment•

scholarly journals Statistical analysis of the design procedure used in reinforced concrete pipes

2020 ◽  
Vol 13 (1) ◽  
pp. 69-86
Author(s):  
F. M. FLORESTA ◽  
C. S. VIEIRA ◽  
L. A. MENDES ◽  
D. L. N. F. AMORIM
Keyword(s):  
Reinforced Concrete ◽  
Aspect Ratio ◽  
Structural Design ◽  
Design Procedure ◽  
Design Procedures ◽  
Concrete Pipes ◽  
Actual Behaviour ◽  
Design Values ◽  
Present Aspect ◽  
Internal Forces

Abstract Structural design procedures are based on simplified hypotheses that attempt to approximate the actual behaviour. Depending on the adopted hypothesis, the design procedure may not satisfactorily describe the structural actual behaviour. Such condition occurs in the design of reinforced concrete pipes, where there are uncertainties related especially on the internal forces and the installation type of the pipe. Moreover, the main design hypothesis is that the cross section is plane and perpendicular to the deformed axis. Based on materials resistance principles it is known that this hypothesis is unsatisfactory to pipes with aspect ratio lower than ten. Note that the commercial reinforced concrete pipes usually present aspect ratio well below ten. In the light of the foregoing, the main objective of this paper is to analyse the accuracy of the design procedure for reinforced concrete pipes. Therefore, statistical processes were used to compare design values with experimental results. The comparisons in this paper showed that the design procedure results in oversized pipes.

Problems of Optimal Structural Design

1968 ◽  
Vol 35 (1) ◽  
pp. 102-106 ◽  
Author(s):  
W. Prager ◽  
J. E. Taylor
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Elastic Stiffness ◽  
Uniform Method ◽  
Design Parameters ◽  
Maximum Stiffness ◽  
Subsequent Determination ◽  
Elastic Design ◽  
Optimal Plastic Design

The paper presents a uniform method of treating a variety of problems of optimal design of sandwich structures. The design procedure consists of two steps: The integration of an optimality condition, which is a differential equation for the optimal displacement field that does not involve any design parameters, and the subsequent determination of the optimal distribution of elastic stiffness or plastic resistance from the usual differential equations of the structure. Optimal elastic design for maximum stiffness, maximum fundamental frequency, or maximum buckling load, and optimal plastic design for maximum safety are treated as examples.

Structural Design and Optimization of a 3-Axis Miniaturized Machine Tool with High Precision Positioning Stages

2007 ◽  
Vol 339 ◽  
pp. 321-326
Author(s):  
J.H. Lee ◽  
Wei Wang ◽  
Sung Hwan Kweon ◽  
Young Shin Kim ◽  
Young Moon Lee ◽  
...  
Keyword(s):  
Machine Tool ◽  
Structural Design ◽  
Evaluation Method ◽  
Error Function ◽  
Design Procedure ◽  
Design Parameters ◽  
Volumetric Error ◽  
Design And Optimization ◽  
Suitable Structure ◽  
Previous Design

The procedure of structural design on miniaturized machine tool (mMT) is proposed and structural optimization by applying robustness evaluation method is presented in this paper. The design procedure of a kind of mMT which is a 3-axis miniaturized milling machine tool (mMMT) is discussed and three different structures of mMMT are proposed based on previous design procedure. The most suitable structure is selected using robustness evaluation method, which is Taguchi method, due to volumetric error function. The design parameters of selected structure are optimized.

scholarly journals Some Remarks on the Choice of Ductility Class for Earthquake-Resistant Steel Structures

2013 ◽  
Vol 21 (3) ◽  
pp. 1-10
Author(s):  
Miroslava Matejčeková-Farhat ◽  
Rudolf Ároch
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Steel Structures ◽  
Design Parameters ◽  
Eurocode 8 ◽  
Design Practice ◽  
Earthquake Resistant ◽  
Earthquake Resistant Structures ◽  
Design Requirements ◽  
National Practice

Abstract The implementation of the Eurocodes in current structural design practice has brought about a new emphasis on the design of earthquake-resistant structures. In some European countries, new earthquake zones have been defined; henceforth, the design requirements of many ongoing projects have changed as well. The choice of the ductility class of steel structures as one of the key design parameters, the consequences of this choice on design procedure, and some applications of the Eurocode 8 design criteria by comparing French and Slovak national practice are discussed, using a practical example of a structure.

scholarly journals Normative and methodological principles for transverse webs structural design as applicable to cargo tank area of double hull oil tankers

2020 ◽  
Author(s):  
К.В. Плотников
Keyword(s):  
Design Process ◽  
Structural Design ◽  
Design Procedure ◽  
Direct Analysis ◽  
Design Parameters ◽  
Element Analysis ◽  
Structural Rules ◽  
Functional Relations ◽  
Oil Tankers ◽  
Double Hull

Статья посвящена вопросам проектирования поперечных танкерных рам крупнотоннажных нефтеналивных судов, размеры корпусных конструкций которых должны соответствовать требованиям Общих Правил МАКО (CSR). Требования Правил CSR можно разделить на общие нормативные предписания аналитико-эмпирического характера (prescriptive-требования) и требования к выполнению проверочных расчётов (в первую очередь с использованием МКЭ). В работе рассмотрены алгоритмы проектирования поперечных рам нефтеналивных судов в соответствии с prescriptive requirements, а также предложена методика и алгоритм проектирования таких конструкций, включающие и МКЭ-анализ, которые могут использоваться в практике конструкторских бюро. Приведено обоснование необходимости анализа и обобщения проектных решений в части рамных конструкций на реальных судах, которые могут быть использованы при разработке специализированного программного обеспечения. Поскольку напряжённо-деформированное состояние рамной конструкции зависит от соотношения характеристик изгибной жесткости составляющих её балок, целесообразным является построение алгоритма проектирования, частью которого является решение оптимизационно-поисковой задачи определения требуемых размеров конструкции. Ограничения такой задачи должны формироваться на основе общих требований CSR. В тексте приведено описание нормативных требований и основные их особенности. Кратко описаны возможные варианты постановки задачи и соображения о программной реализации её решения. The paper deals with principal considerations of double-hull oil tankers primary supporting members (PSM) structural design, which meets the requirements of Common Structural Rules (CSR). The algorithms of structural design procedure for different typical arrangements of tankers are considered in the paper. The study shows main features of structural design process that lead to complexity of functional relations. As CSR requirements consist of prescriptive requirements and direct analysis requirements (that usually means finite element analysis) the suggested algorithms include both of these stages. The text explains the need of statistical data of existing designs collecting. Such data includes ratios between required and actual web depths, scantlings of brackets, ratios between moments of inertia of PSM and some others. This data can be used in structural design process and form the limitations of design parameters. As shear forces and bending moments in primary supporting members depend on ratios of its bending stiffness and relation between design parameters are rather complicated it is appropriate to use mathematical programming models, which present a decision support instrument. There are many ways of formulation and implementation of structural design task, and the paper gives general considerations about it. The brief review of previous contributions on this subject is also given.

Seismic design of base-isolated highway bridges utilizing lead–rubber bearings

1990 ◽  
Vol 17 (3) ◽  
pp. 413-422 ◽  
Author(s):  
A. Ghobarah ◽  
H. M. Ali
Keyword(s):  
Seismic Design ◽  
Base Isolation ◽  
Time History ◽  
Highway Bridges ◽  
Response Spectra ◽  
Design Guidelines ◽  
Design Parameters ◽  
Seismic Behaviour ◽  
Isolation System ◽  
Design Procedures

A study is made of the seismic behaviour of base-isolated highway bridges with the objective of developing design procedures in the form of code-type approach. The recommendations of current codes concerning the use of energy dissipation mechanisms for the seismic design of bridges are reviewed. A model representing the bridge deck, piers, and the base-isolation system is used to evaluate the response of the bridge to a selected earthquake time history record and to evaluate the effects of various design parameters on the dynamic response. The results of this analysis are used in the development of design guidelines for the isolated bridge system. It was found that base isolation affects the design forces on piers and abutments as well as the deck displacements. An optimum design should provide a reasonable balance between the shear forces on supports and tolerable displacements. Two design procedures are proposed based on the time history and inelastic response spectra approaches. Simplified charts are presented which aid in the seismic design of new bridges as well as in the upgrading of existing ones. Key words: dynamic, seismic, design, highway, bridges, earthquake, base isolation.

scholarly journals The capacity design of reinforced concrete hybrid structures for multistorey buildings

1986 ◽  
Vol 19 (1) ◽  
pp. 1-17 ◽  
Author(s):  
T. Paulay ◽  
W. J. Goodsir
Keyword(s):  
Reinforced Concrete ◽  
Design Procedure ◽  
Structural Response ◽  
Hybrid Structures ◽  
Design Parameters ◽  
Capacity Design ◽  
Structural Walls ◽  
Design Procedures ◽  
Fixed Base ◽  
Selection Of

To complement existing capacity design procedures used in New Zealand for reinforced concrete buildings in which earthquake resistance is provided by ductile frames or ductile structural walls, an analogous methodology is presented for the design
of ductile hybrid structures. Modelling and types of structures in which the mode of wall contribution is different are briefly described. A step by step description of a capacity design procedure for a structural system in which fixed base ductile frames and walls, both of identical height, interact, is presented. The rationale for each step is outlined and, where necessary, evidence is offered for the selection of particular design parameters and their magnitudes. A number of issues which require further study are briefly outlined. These relate to irregularity in layout, torsional effects, diaphragm flexibility, shortcomings in the predictions for dynamic shear demands in walls, and to limitations of the proposed design procedure. It is believed that the methodology is logical, relatively simple and that it should ensure, when combined with appropriate detailing, excellent seismic structural response.

Field and Laboratory Properties of Roller-Compacted Concrete Pavements

2017 ◽  
Vol 2630 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Jeffrey LaHucik ◽  
Jeffery Roesler
Keyword(s):  
Compressive Strength ◽  
Design Procedure ◽  
Field Performance ◽  
Mixture Design ◽  
Concrete Pavements ◽  
Conventional Concrete ◽  
Fracture Properties ◽  
Design Procedures ◽  
Roller Compacted Concrete ◽  
Gyratory Compaction

Roller-compacted concrete (RCC) pavements present three primary challenges relative to conventional concrete pavement: mixture design, structural design details, and construction process and verification. An investigation was initiated to reconcile the discrepancy between the field and laboratory properties of RCC pavements because of differences in laboratory mixture design procedures and field construction processes. Four RCC pavement projects in Illinois were selected for field coring along with sampling of RCC constituent materials for replication of the laboratory mixture design. Density measurements of field cores indicated that density decreased with depth into the pavement structure and the relative density at paving-lane joints could be as low as 80%. Statistical differences in compressive strength and fracture properties between field and laboratory samples were observed and result from differences in density. A 4% difference in density between field and laboratory samples resulted in an approximate 45% difference in compressive strength. The reduction in field RCC strength and fracture properties relative to the values obtained in the laboratory will result in decreased slab flexural capacity and field performance. Application of the gyratory compactor demonstrated that it can be used repeatedly to compact most RCC mixtures to similar target densities as the modified Proctor method and field-extracted cores. The gap between field and laboratory properties of RCC can be reduced by application of high-density pavers; improvement in mixture design procedure with the gyratory compaction method; a foundation layer beneath the RCC that is stiffer, thicker, or both; reduced RCC lift thicknesses to achieve specified density; or all of these.

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