Mechanistic-Empirical (ME)

The following controls, located on the Design -> Mechanistic Page, are used to perform a Mechanistic-Empirical (ME) design check.

CalME can perform a Deterministic or Monte Carlo simulation depending on what is selected for Simulation Type. A Deterministic simulation performs a single simulation, using the properties defined on the Project Information page, while a Monte Carlo performs many simulations in which properties are randomly selected from a distribution of those properties. The number of simulations performed in a Monte Carlo is set in the Monte Carlo Variability section.

The length of time (in years) for the simulation(s) is initially set to the Design Life. You may change the simulation duration to be something other than the Design Life on this page (#5 below). Simulation Duration is reset to Design Life whenever it is changed. The start date for the simulation begins at what is set for Start Date.

This page has four sections of information:

•The top section - shows the current project and trial (#1 and #2), buttons for starting and canceling simulations (#3), progress on the simulation, summary data for the current project trial (#4), simulation duration (#5), selection of graph type for the layer moduli (6), navigation buttons for the Graph and Report pages (#7 and #8) and a messaging area

•Real-time graphing display for rutting (average of the simulations for a Monte Carlo) and cracking (average of the simulations for a Monte Carlo) curves, and allowable rutting and allowable cracking (#9) horizontal lines

•Real-time graphing display for minimum and maximum for pavement layer moduli (#10)

•A scrollable text box control that displays pavement Layer Compression (#11) and Expected Life (#12) reports, once the simulation is complete

Section notes:

1.Shows the currently loaded CalME project

2.Shows the currently loaded CalME trial within the currently loaded project

3.Selecting the "Run Simulation" button starts the simulation. Selecting "Cancel" will stop the simulation. The amount of clock time required for the simulation(s) depends on the Simulation Duration (#5) and the Number of Simulations. Typical design checks (Design Life = 40 years and Number of  Simulation = 50) will take around 3 minutes. In addition, when there are many simulations (50+) the response curves shown in sections 9 and 10 will take around 30 seconds to begin showing progress. For a Deterministic simulation, the response curves begin almost immediately.

4.The progress of the simulation(s) is shown here by showing the number of seconds from the start of the simulation. "Sim Done" is shown when the simulation is complete, and "Rpts Done" will be shown after the reports have been generated and displayed. For a "large" simulation, the reports take around 5 - 6 seconds to be generated. Any messages generated during the simulation(s) will be shown in the grayed out messaging area. Several pertinent data items for the current project trial (type of simulation, number of simulations, Design Life and the TI) are also presented.

5.Simulation Duration - this data item defaults to the Design Life but may be changed to a value less than the Design Life or a value larger than the Design Life. It is reset back to the Design Life whenever the Design Life is changed.

6.A check box to select the graph type (arithmetic or logarithmic) for the real-time display of the layer moduli.

7.Button to navigate to the Graph Page after the simulation is complete.

8.Button to navigate to the Report Page after the simulation is complete.

9.This graphs shows the rutting and cracking of the surface, in real-time, as the simulation progresses. There are also horizontal lines for allowable rutting and allowable cracking. When performing a Monte Carlo simulation, rutting and cracking responses are presented as the average of all simulations. The responses for rutting and cracking for all simulations can be seen by going to the Graphs page by selecting the "Graphs" button shown at #7 above. You can see exact values for points on any curve by moving the mouse over it during the simulation or after, as shown in the Rutting and Cracking graph area (#9).

10.This graph show pavement layer moduli. For a Deterministic simulation there will be a single curve for each layer, while for a Monte Carlo simulation, there will be minimum and maximum curves for each layer (2 curves), as opposed to showing curves for every simulation. The layer number is appended to "Min-E" and "Max-E", e.g., Max-E1 is the maximum modulus (E) curve for Layer 1. The modulus curves for all simulations and for all layers can be seen by going to the  Graphs page by selecting the "Graphs" button shown at #7 above. You can see exact values for points on any curve by moving the mouse over it during the simulation or after, as shown in the Rutting and Cracking graph area (#9).

11.This section of the page presents the Layer Compression Report after the simulation is complete.

12.The Expected Life Report is presented after the Layer Compression Report

The question mark in the blue circle in the upper-right of the control group allows you to get help on the controls (this topic).