A parameter setup contains information that defines the local environmental conditions, traffic characteristics, and material performance characteristics. It is used by the remaining life and overlay design function of Elmod 6. Elmod 6 allows the user to create and tailor parameter files to just about any conditions. It is customary to create a parameter file that is relevant to a specific job, area, environment, set of materials, or network of pavements. These parameter setups can be saved and/or altered to meet specific project requirements, as necessary. The information contained in the parameter file is extremely important and is basically the heart of the design process. Problems with overlay design calculations can often be attributed to the presence of unrealistic or inaccurate information in this file.
A list of parameter setups is presented by clicking on the Parameters menu item. A new parameter file can be created by changing parameters in an existing file and saving it under a new name. The new parameter file may be saved for the specific project only and/or as a permanent file made available to all future projects. NOTE: If the changed parameters are saved under the original file name, the original file is overwritten.
You can edit all input fields on all tabs before saving. All changes will stay in memory until you press the Save, Delete or Cancel buttons.
Save setup will overwrite your existing loaded setup.
Save as new Setup will ask for a name for the new setup, and then add this to the
list of available setups.
Save as permanent Setup will ask for a name of the name setup and add this to
the list of available setups for all new created databases. The default setups coming with the installation can not be overwritten or deleted.
Delete will permanently remove the loaded setup from the list of available
setups.
Cancel will return to menu without saving any changes you have made. Export gives the possibility to export the setup to another project database. A
Browser will open to allow you to identify which project database to export to.
present in the project database. When you create a new database all the
permanent parameter setups will be copied to the project database. In this way you can select if you want to modify parameter setups only for the current project, or if you want to make permanent changes.
When you have selected which parameter setup to work with all data for the specified setup is loaded into 4 tabs: Seasons , MaterialTypes , Vehicles , and
Wheels From the materials option DesignCriterias can be setup for each
defines material type. When finished, the user can store the parameters under a new filename, or overwrite the existing file.
13.1 Seasons
For design purposes, the year may be divided into seasons, with a maximum of 12 seasons. The program calculates moduli corresponding to each season, with respect to seasonal temperature for the asphalt layer and the time elapsed since spring thaw or wet period for the unbound materials (including the subgrade).
The remaining life and associated overlay design is then based on the cumulative amount of damage occurring during each season for all design loads using Miner's law.
The user subdivides the year into seasons. For each season the length in weeks is entered, as well as the week to be considered characteristic of that season. The week number is counted from the beginning of the year. The characteristic week is the week in which all the loads of the season would result in the same damage as when the loads are spread out over the season. By subdividing a season Elmod
6 may be used, through a trial and error process, to accurately determine which
week is characteristic. Total number of weeks must add up to 52.
The first season will start 1st of January, which means that you would need to divide a season into two seasons if it overlaps this date.
If loads are evenly distributed over the year you can click the Even distribution button and Elmod will calculate the accurate percentage values to put into the load per season fields.
When you modify seasonal temperatures or factors on the Material Types tab, you have graphics available to see the effect of the settings for each season. From this graphics you also have the possibility of adjusting the characteristic week inside each season.
13.2 Materials
When selecting the Material Types tab you get the possibility to see and edit all information in the setup that relates to each of the defined materials.
In the list box to the left you have the current list of materials, and the
information on the tab relates to the highlighted item in the list. You can click in the list to view the other material’s properties.
Create new material button adds a new material to the list. You will be asked to
assign a name for the material (must be unique for the setup), and the new material will be added with properties which are a copy of the currently selected material. You can proceed by changing any values for the new material. Nothing will be saved before you click one of the save buttons on the right hand side, but
all changes will be stored in memory even if you select other material types to view and edit.
Delete current material removes the material from the list.
Material Name replicates the highlighted name from the list box. It is not
possible to change the name due to reference conflicts. Alternatively you can create a new material with the desired name, and delete the existing material.
Material Type can be selected from the dropdown box. The information is used
in the design procedures to determine the number of bound layers.
Ref. Modulus. The reference modulus of the material is used as the design value
in case the material is chosen as the design material. The value is also used to optionally be inserted as seed value in Structures window.
Temperature dependant. This defines whether the material modulus is sensitive
to temperatures. If it is checked the tab Temperature dependency will be enabled for definition of the modulus/ temperature relationship. The title of the last tab will be Seasonal temperatures for defining temperature variation over the year. If “Temperature dependant” is not checked the last tab will show
Seasonal factors for defining modulus variation over the seasons due to other
reasons, like frost/thaw periods or rainy seasons affecting the condition of the unbound materials.
Fatigue Cracking and Permanent Deformation. This defines which criteria
should be used for determining the residual life of the material. The details for selecting the criteria are on the related tabs below. Usually you operate with fatigue cracking for bound materials and permanent deformation for unbound materials. It is possible to have them both switched off, in case it is not desirable to have these materials properties influencing the design calculations.
Hatch. Select a pattern to be associated with this material. Click on the pattern to
open a window for the possible selections.
Min. and Max Modulus. This input can be used to force the backcalculation to
produce moduli results within the given range. Be aware that this will influence the moduli calculated for the remaining layers as well.
Fatigue Cracking and Permanent Deformation
These two tabs are enabled depending on the choice for using Fatigue Cracking relations or Permanent Deformation relations in the checkboxes above the tabs. In the relation N is the traffic and E the modulus of the material. The constants