Improved Surface Drainage of Pavements Final Report (1998) / Chapter Skim
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Appendix A Program Overview
Appendix A Program Overview
Pages 141-172
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From page 141... ...
The water film thickness is used to estimate the speed at which hv~ronIanin~ ,` ~, will occur. A worst-case scenario is examined by determining the water film thickness and hydroplaning speeds along the longest flow path length under steady-state conditions with a uniform rainfall rate.
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From page 142... ...
2. From the W~ndowsw menu bar at the top of the screen, use the mouse and the left hand mouse button to click on File.
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From page 143... ...
It is also used to display the output from the PAVDRN program, which includes information about water film thickness and hydroplaning speeds along the length of the flow path.
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The output file and the data file are ASCH files and can be edited using a text editor such as the Notebook editor found In the Accessories group of W~ndowsTM.
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From page 145... ...
The tangent section is the only section that accommodates different texture depths, cross-sIopes, and pavement types within a single section. All other sections have only one value for each of these variables in the PAVDRN model.
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Example of PAVDRN input screen 1, environment and section type.
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A tangent section is a straight section that may consist of up to ten planes (sections with varying sloped that have unique cross-slopes, widths, texture depths, and/or pavement types. HonzontaZ Curve Section.
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AM Plan Profile by HoNzonte' Cur Simon A AM Plan Profile and c] Crest and Sag Verbal Cu~s Figure A-2.
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From page 149... ...
Water Temperature The temperature of water flowing over the pavement surface must be selected by the user In mats of °F or °C. Kinematic Viscosity of Water The kinematic viscosity used In this simulation is expressed ~ units of ft2/s, m2/s.
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From page 150... ...
Multiple (Joined) Sections If the simulation is set up for a pavement section that is downstream from a previously analyzed section, and if the program output for the previously analyzed section indicates that the flow path extended to the end of the section, click on the box.
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From page 151... ...
Data Input - Screen 2 Tangent Section ~Numbe' of Planes _ _ 1 ~ ~Scct'an Lcngth 110110 ~ r pavement Grader 1-01 1 ~Step S=e ~ Plane Properties _ Plane 1 ~Plane W;dth 112 1 Pavement Type O DG^C ~ PCC Q OGAC O G-PCt: F[:'oss~ope 1 |.015 ~ rTcxhre Depth l I Q2 1 Figure A-3. Example of PAVDRN input screen 2, geometric requirements for Portland cement concrete pavement.
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From page 152... ...
Example of PAVDRN input screen 3, geometric requirements for porous asphalt.
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From page 153... ...
m) determines the points along the flow Pam at which the water film thickness and hydroplaning speeds are computed.
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From page 154... ...
When grooved PCC is selected as the pavement type, text boxes for the groove spacing, the groove width, and ache groove depth are displayed. This information is used to effectively increase the mean texture depth of the pavement.
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From page 155... ...
The texture depth is the mean texture depth using a standard sand patch test (ASTM E 965) or equivalent fin, mm)
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From page 156... ...
There are four types of pavements are used in PAVDRN; they are: · PCC: Portland cement concrete, · GPCC: Grooved Portland cement concrete, · DGAC: Dense-graded asphaltic concrete, and · OGAC: Open-graded or porous asphaltic concrete. When grooved PCC is selected as He pavement type, text boxes for the groove spacing, the groove width and the groove depth are displayed.
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From page 157... ...
m) determines the points along the flow path at which the water film thickness and hydroplaning speeds are computed.
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General Data for Transition Section Three items, pavement type, texture depth, and step size apply to the entire transition section.
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. This value determines the points along the flow path at which the water film thickness and hydroplaning speeds are computed.
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Texture Depth. Mean texture depth using a standard sand patch test or equivalent (in, mm)
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Direction of Flow from the Crest. This item requires that the user determine for which side of the crest vertical curve PAVDRN will calculate the water film chic Hess aunt hydroplaning speeds.
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From page 162... ...
Texture Depth. Mean texture depth using a standard sand patch test or equivalent fin, mm)
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From page 163... ...
Four types of pavements are used in PAVDRN; they are: · PCC: Portland cement concrete, · GPCC: Grooved Portland cement concrete, · DGAC: Dense-graded asphaltic concrete, and · OGAC: Open-graded or porous asphaltic concrete. When grooved PCC is selected as the pavement type, text boxes for the groove spacing, the groove width and the groove depth appear.
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From page 164... ...
TEST DATA SET - USERS GUIDE Table Apt. PAVDRN input data set.
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From page 165... ...
948-6127 Pennsylvania Transportation Institute The Pennsylvania State University University Park, PA 16802 Sponsored by the National Cooperative Highway Research Program NCHRP Project 1-29 Program started on 5/ 1/1997 at 22:55:59 TEST DATA SET - USERS GUIDE Tangent Section - 4 lone pavement with variable cross-slope PCC Pavement Type of section System of units for input and output Number of consecutive planes Rainfall intensity (in/h, mm/in) Kinematic viscosity (sq.ft./s, sq.m.is)
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From page 166... ...
* denotes hydroplaning speeds less then the facility design speed of 55.
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From page 167... ...
This location varies with different pavement section types as described in the following section. The water film thickness above the pavement roughness asperities and the flow-per-unit width of the plane along the flow path are also displayed.
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From page 168... ...
. Horizontal Curve Section The origin is difficult to identify, however, the terminal point of the flow path is the lowest point ~ the curve.
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This is not necessarily the end with the smallest slope but, rather, the end where the change ~ cross-sIope per unit per length is the smallest. Crest Vertical Curve Section The outlet of the flow path is located at the lower edge of the pavement section at the PC or Pr, depending upon which side of the vertical curve is being analyzed.
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From page 170... ...
The x-coordinate of the origin is located using the value shown ~ the printout. Sag Vertical Curve Section The outlet of the flow path is located at the lower edge of the pavement section, i.e., the sag, where the longitudinal slope is zero.
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From page 171... ...
, and tire tread depth, 2.4 mm (3/32 Ins, were used in the PAVDRN model to generalize Gallaway's expression. One method for the selecting the design rainfall intensity for the hydroplaning analysis is based on the frequency and duration of an event.
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From page 172... ...
Rainfall intensity for stopping sight distances. Design Speed Stopping Sight Maximum Rainfall Intensity, m/in, (kmlh)
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