Flexible Pavement Overlays: The State Experience

1997 ◽  
Vol 1568 (1) ◽  
pp. 139-147
Author(s):  
Peter E. Sebaaly ◽  
Stephen Lani ◽  
Sohila Bemanian ◽  
Christopher Cocking
Keyword(s):  
Design Method ◽  
Design Procedure ◽  
Survey Method ◽  
Department Of Transportation ◽  
Significant Discrepancy ◽  
Design Engineers ◽  
Routine Basis ◽  
Final Design ◽  
Overlay Design ◽  
Nondestructive Testing Method

The design and construction of flexible overlays has become a popular exercise. However, there is not a simple, straightforward, and yet reliable design procedure that the design engineer can implement on a routine basis. The data needed for overlay design are not easily accessible to the design engineer, and yet the accessible data are not fully reliable in most cases. The process by which the design engineers at the Nevada Department of Transportation handle overlay design is presented. The various steps followed and the obstacles that the design engineer encounters in the search for the necessary data and the final design process are described. Major assumptions must be made along the way that could significantly affect the final design. Three case studies are presented. Each project was designed using three different design methods, including the AASHTO nondestructive testing method, the AASHTO condition survey method, and the Nevada Department of Transportation (NDOT) mechanistic overlay design method. All three methods used the same data gathered by the design engineer for each project. The analysis indicates that there is a significant discrepancy between the two AASHTO methods, whereas the NDOT method and the AASHTO condition survey method agreed on one project.

Asphalt Concrete Overlay Design Case Studies

1996 ◽  
Vol 1543 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Linda M. Pierce ◽  
Joe P. Mahoney
Keyword(s):  
Case Studies ◽  
Design Procedure ◽  
Washington State ◽  
Falling Weight Deflectometer ◽  
Department Of Transportation ◽  
Design Procedures ◽  
Overlay Design ◽  
Washington State Department ◽  
Falling Weight ◽  
The University

During the late 1980s, the Washington State Department of Transportation (WSDOT), the University of Washington, and the Washington State Transportation Center developed a mechanistic-empirical flexible overlay design procedure. Following development, WSDOT implemented this overlay design procedure and has been evaluating flexible overlay projects for approximately the past 8 years. WSDOT rehabilitates about 100 projects each year; approximately 20 to 30 percent of the total projects are designed using the WSDOT overlay design procedure and the AASHTO overlay design procedure (using DARWin). These two procedures are discussed in general, and two case studies illustrate each of the overlay design procedures. Also included is the backcalculation of layer moduli from falling weight deflectometer data.

A Pavement Design and Rehabilitation System

1996 ◽  
Vol 1539 (1) ◽  
pp. 110-115 ◽  
Author(s):  
Jacob Uzan
Keyword(s):  
Load Distribution ◽  
Design Method ◽  
Design Procedure ◽  
Pavement Design ◽  
Equivalent Temperature ◽  
Pavement Condition ◽  
Rehabilitation System ◽  
Overlay Design ◽  
Available Information ◽  
Pavement Thickness

Because the Superpave system is not readily available for use, an interim pavement design and rehabilitation method was developed that can be used for Israeli traffic and environmental conditions. The existing method was upgraded to include most of the relevant available information and to produce reliable pavement design for the specific conditions in Israel. The upgrading concentrated on multiple topics. An axle-load distribution specific to Israeli conditions was included because analysis indicates that axle loads in Israel are typically above the standard 80-kN single axle load. The extended California bearing ratio (CBR) method was adapted to a variety of axle-load combinations by using Miner's law for damage accumulation. Converting the axle-load distribution to the standard 80-kN equivalent single axle load leads to underdesign of approximately 10 percent in pavement thickness (or to a reduction of about 70 percent of the design life). A fatigue consideration to determine the asphalt-layer thickness was added. Local temperatures were analyzed to determine an equivalent temperature for fatigue calculation. For Israeli conditions, an equivalent temperature of 14°C can be used countrywide for asphalt-layer thicknesses up to 250 mm. An overlay design method consistent with the upgraded design procedure was assembled. It includes backcalculation of layer moduli to determine the subgrade CBR and the quality of the pavement layers; pavement condition surveys to evaluate a representative effective thickness of the asphalt layer; and component-layer analysis to determine the overlay thickness.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

AN INDEPENDENT ACTIVE BALANCER FOR PLANAR MECHANISMS

2007 ◽  
Vol 31 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Zhang Ying ◽  
Yao Yan-An ◽  
Cha Jian-Zhong
Keyword(s):  
Working Conditions ◽  
Design Method ◽  
Design Procedure ◽  
Vibration Absorber ◽  
Planar Mechanisms ◽  
Dynamic Balancing ◽  
Joint Coupling ◽  
Design Requirements ◽  
Novel Concept ◽  
Two Degree Of Freedom

This paper proposed a novel concept of active balancer for dynamic balancing of planar mechanisms. Somewhat similar to a vibration absorber, the active balancer is designed as an independent device, which is placed outside of the mechanism to be balanced and can be installed easily. It consists of a two degree-of-freedom (DOF) linkage with two input shafts, one of which is connected to the output shaft of the mechanism to be balanced by a joint coupling, and the other one is driven by a controllable motor. Flexible dynamic balancing adapted to different working conditions can be achieved by varying speed trajectories of the control motor actively. A design method is developed for selecting suitable speed trajectories and link parameters of the two DOF linkage of the balancer to meet various design requirements and constraints. Numerical examples are given to demonstrate the design procedure and to verify the feasibility of the proposed concept.

scholarly journals Novel Robust Design Method of Multilayer Optical Coatings

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suyong Wu ◽  
Xingwu Long ◽  
Kaiyong Yang
Keyword(s):  
Robust Design ◽  
Optimization Design ◽  
Design Method ◽  
Analytical Calculation ◽  
Design Procedure ◽  
Deposition Process ◽  
Practical Significance ◽  
Optical Coatings ◽  
Optical Films ◽  
Robust Design Method

We present a novel fast robust design method of multilayer optical coatings. The sensitivity of optical films to production errors is controlled in the whole optimization design procedure. We derive an analytical calculation model for fast robust design of multilayer optical coatings. We demonstrate its effectiveness by successful application of the robust design method to a neutral beam splitter. It is showed that the novel robust design method owns an inherent fast computation characteristic and the designed film is insensitive to the monitoring thickness errors in deposition process. This method is especially of practical significance to improve the mass production yields and repetitive production of high-quality optical coatings.

Multi Mode Vibration Control and Broder Band Motion Control of Three Dimensional Shaking Table

2005 ◽  
Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Equation System ◽  
State Equation ◽  
Shaking Table ◽  
Mode Vibration ◽  
And Control

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.

scholarly journals Semi-Inverse Design of Compressor Cascades, Including Supersonic Inflow

1990 ◽  
Author(s):  
A. Kirschner ◽  
H. Stoff
Keyword(s):  
Flow Field ◽  
Design Method ◽  
Axisymmetric Flow ◽  
Three Dimensional ◽  
Design Procedure ◽  
Meridional Plane ◽  
Simple Method ◽  
Blade Loading ◽  
Through Flow ◽  
Blade Element

A cascade design-method is presented which complements the meridional through-flow design procedure of turbomachines. Starting from an axisymmetric flow field and the streamline geometry in the meridional plane this simple method produces a solution for the quasi three-dimensional flow field and the blade-element geometry on corresponding stream surfaces. In addition, it provides intra-blade data on loss and turning required for a consistent design and a convenient means of optimizing blade loading. The purpose of this paper is to describe the theoretical basis of the method and to illustrate its application in the design of transonic compressors.

scholarly journals An Artificial Intelligence–Assisted Design Method for Topology Optimization without Pre-Optimized Training Data

2021 ◽  
Vol 11 (19) ◽  
pp. 9041
Author(s):  
Alex Halle ◽  
Lucio Flavio Campanile ◽  
Alexander Hasse
Keyword(s):  
Topology Optimization ◽  
Input Data ◽  
Design Method ◽  
Design Procedure ◽  
Computational Effort ◽  
Training Data ◽  
Geometry Design ◽  
Random Input Data ◽  
Degree Of Filling ◽  
Initial Process

Engineers widely use topology optimization during the initial process of product development to obtain a first possible geometry design. The state-of-the-art method is iterative calculation, which requires both time and computational power. This paper proposes an AI-assisted design method for topology optimization, which does not require any optimized data. An artificial neural network—the predictor—provides the designs on the basis of boundary conditions and degree of filling as input data. In the training phase, the so-called evaluators evaluate the generated geometries on the basis of random input data with respect to given criteria. The results of those evaluations flow into an objective function, which is minimized by adapting the predictor’s parameters. After training, the presented AI-assisted design procedure generates geometries that are similar to those of conventional topology optimizers, but require only a fraction of the computational effort. We believe that our work could be a clue for AI-based methods that require data that are difficult to compute or unavailable.

scholarly journals Urban Ensembles: An integrated approach to design in steep, urban landscapes

2021 ◽  
Author(s):  
◽  
Myren Burnett
Keyword(s):  
Architectural Design ◽  
Landscape Architecture ◽  
Design Method ◽  
Methodological Approach ◽  
Strong Relationship ◽  
Integrated Approach ◽  
Urban Site ◽  
Urban Landscapes ◽  
Final Design ◽  
Urban Terrain

<p>Urban Ensembles explores the way in which landscape and architecture can be employed together within the design of a steep, urban site. Lyttelton is a small port town on the border of Christchurch, settled in the foothills of a harbour formed by a major volcanic eruption. This rugged setting, with steeply sloping urban terrain, presents an interesting challenge when designing an urban development. The site was badly damaged in a series of earthquakes in 2010-2011, and many of the town’s oldest buildings, heritage structures dating back to the colonial settlement era, were destroyed. This has left a void in the heart of Lyttelton, and caused the loss of much of the tourism business that the town relies upon for its income. This thesis takes a methodological approach to the design of landscape architecture on such a challenging site. A range of techniques are explored, drawing from both landscape and architecture to explore the roles that each discipline plays in the design of urban spaces. The frequent imbalance between disciplines is addressed both through the literature review and design method, as this landscape architecture thesis draws on architectural design as a tool for generating spaces which fall somewhere in between the two ideals of interior and exterior. The final design proposal is an alternative rebuild plan for the central business area to the south of London St, and also addresses the relationships between that site and the surrounding context, both urban and environmental. The aim of this design is to create a series of interconnected spaces which have a strong relationship to the surrounding harbour setting, and also to facilitate development of the pedestrian spaces throughout the block and encouraging the development of activity at the street level, through the interface between buildings and landscape.</p>

scholarly journals The House Reformed: A Reaction to Suburban Monotony

2021 ◽  
Author(s):  
◽  
Florence Mangan
Keyword(s):  
Design Method ◽  
Well Being ◽  
Mass Scale ◽  
Life Styles ◽  
Hands On ◽  
Final Design ◽  
Manual Methods ◽  
The Aesthetic ◽  
House Design ◽  
Made In

<p>Joyless rows of monotonous houses are be- ginning to define the suburban typology of tomorrow. Quality and innovation is being compromised for speed and quantity and there is a distinct lack of consideration for the home’s potential to enrich and influence the life-styles and well-being of its occupants.  This thesis is a reaction to the researcher’s dis- satisfaction with New Zealand’s suburban typology and seeks to identify and demonstrate an alternative design approach. The research- er considers that a house should enable its occupants to flourish by instigating moments of joy and surprise whilst maximising economy of space.  The thesis uses an investigative research method of five different design tests. Each test reveals strategies to aid the approach of designing the suburban typology, focusing on maximising joy, surprise and economy of space.  Both digital and manual methods are used, revealing their respective strengths and flaws. The Digital method used in the Data House and Rigid x Fluid house tests lacked the ability to apply tangible aesthetic qualities to a de- sign. The manual hands on method of used in the Patchwork House and House Reformed tests was hugely beneficial for the aesthetic qualities of design, however it lacked the rigor and capacity to apply individuality on a mass scale.  Discoveries made in the thesis investigations are collated in a final design outcome, the House Reformed. This house design demonstrates a compilation of the successful strategies identified in the research and reveals the benefits of approaching home design with qualities of joy, surprise and economy of space. The most successful strategies used to achieve these aims were establishing a great- er connection with the outdoors, providing flexible spaces through the use of innovative partitions and furniture and injecting unexpected aesthetic moments through the use of interesting texture and colour.  Overall the research reveals a successful de- sign outcome and provides interesting in- sights into design method. It explores worth- while questions and issues related to the lived domestic experience such as the lack of joy, surprise and economy of space in suburban housing and demonstrates the importance of designing with such qualities.</p>

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