Overview

The purpose of this technote is to discuss the Pipe Renewal Planner feature available in the Bentley WaterGEMS V8i Select Series 2. Additional information can be found in the WaterGEMS Help menu.

Background

It is often advantageous to know about vulnerable parts of a system so that potential problems can be fixed before they cause system disruptions. Pipe Renewal Planner provides the user with a method to calculate a weighted score for each pipe based on user-defined aspects of the model.

Pipe Renewal Planner can give the user guidance to determine which pipes in the model may be most vulnerable and allow them to remedy issues that have caused the pipe to have a high score.

This is a new feature included with WaterGEMS V8i Select Series 2 (build 08.11.02.31) or later. It is available as a licensing add-on for WaterCAD V8i Select Series 2.

Before using Pipe Renewal Planner

Pipe Renewal Planner provides the user with a method to calculate a weighted score for each pipe based on user-defined aspects of the model. Pipe Renewal Planner can include any aspect that can be entered for a pipe or calculated for the pipe. These include capacity, projected pipe breaks, material, and depth of cover, among others. Scores determined by Pipe Renewal Planner are highly dependent on the specific system and on the availability of data.

Before using Pipe Renewal Planner, the user needs to identify which aspects will be used in scoring pipes and which properties are going to be used as a basis for calculating the aspect scores. It may be necessary to define new properties in User Data Extensions and import values for properties from external data sources using ModelBuilder or copy/paste features. In order to import values, it is essential that there exist a common key field shared by the WaterCAD V8i model and the external data source.

Calculation of raw scores for aspects such as capacity (fire flow) and criticality (shortfall) can be time consuming such that it may be advisable to have already computed these analyses before computing Pipe Renewal Planner. However, if any properties are changed that may affect scores, it is possible to recompute the scenario from within Pipe Renewal Planner.

Also keep in mind that doing the default Pipe Renewal Planner analysis will use fire flow (capacity) results, criticality and segmentation analysis, and pipe break analysis. It is recommended that this is reviewed beforehand, as this technote will only touch on these in general terms. Please review the available technotes or Help items on these features for more information.

Using Pipe Renewal Planner

You can access Pipe Renewal Planner by selecting Analysis > Pipe Renewal Planner or picking the Pipe Renewal Planner icon from the toolbar.

This opens the welcome dialog if no analyses have already been run.

To start a new analysis, click the New icon in the upper left. A new pipe renewal planner label will appear in the list on the left, while the section to the right will be populated with default aspects: pipe break, criticality, and capacity (fire flow).

Each aspect has a select number of properties associated with them. The Selection Set column allows you to choose either the entire network or a predefined selection set of elements for the aspect analysis. The Weight column is a way for you to decide how much emphasis will be placed on a certain aspect in Pipe Renewal Planner. The Scenario column defines which scenario the data for the individual aspect comes from. These different scenarios can be computed ahead of time, which will save some computational time for the Pipe Renewal Planner analysis itself. Computing the scenario ahead of time will also allow you to verify that the results for the aspects are reasonable. However, if you have not computed the scenario, you can put a checkmark in the Compute Scenario column and Pipe Renewal Planner will compute the scenario during the analysis.

In addition to the default aspects, you can also add new aspects for the pipe renewal planner to account for. To do this, either click the New icon below the General tab or simply click in the empty cell beneath the default aspects. Then click in the cell and select the ellipsis button.

This will open the Aspects manager. Select the New icon to create a selection. Then select which property you would like to be considered in the analysis.

Whether you use the default aspects or create new ones, you will need to select the Representative Scenario for the analysis. This does not need to be the current scenario. The representative scenario will be used as the source of element properties and the location to save results except where another scenario is explicitly called out.

Note: Two Pipe Renewal Planner configurations cannot share the same representative scenario. If a scenario is selected, it is not available as the representative scenario from the pulldown menu for other Pipe Renewal Planner configurations.

Computing and Viewing Results

The individual aspects will need to be set up before computing the Pipe Renewal Planner analysis. For information on how run a fire flow analysis, a criticality and segmentation analysis, and a pipe break analysis, please review posted information in Help or in the technotes found in the Hydraulics and Hydrology Technotes page.

Note: the raw score for capacity (fire flow) for a given pipe is equal to the difference between the "target" velocity (the "Pipe velocity greater than" field in the fire flow alternative) and the maximum velocity in that pipe (over all the fire flow events). In order for a pipe to be considered during this part of the calculation, it must either be adjacent to a fire flow node or be included in the "auxiliary output selection set" in the fire flow alternative.

Once you have your aspects selected and applied, you will be ready to compute Pipe Renewal Planner. Click the green Compute icon in the Pipe Renewal Planner manager.

Note: If you have not computed the scenarios associated with the aspects, you will be prompted to do so. You can either compute the scenarios individually or put a checkmark in the Compute Scenario column for the different aspects.

If you click the Results tab, you will see the results of the analysis.

The overall score for the pipe is found in the Pipe Score column. It is the weighted sum of the individual aspect scores. A higher value indicates a pipe with potential problems in need of repair, rehabilitation, replacement or some other remedial action. Scores are presented on a 0 to 100 scale unless the user has set up some different scaling.

Other data included in the results tab include the scores and results for the individual aspects. The data can be sorted by right-clicking on a column header and choosing the Sort function. By choosing “Sort Descending,” the highest score will be at the top.

You can also view the data graphically in the drawing pane by setting up color coding in the Element Symbology manager. Open this by clicking View > Element Symbology. Right-click on Pipe and select New > Color Coding. This will open a new manager.

Choose “Pipe Score” from the Properties pulldown and select the range. You can initialize the color coding on the right side of the manager. More information on color coding can be found under Help.

See Also

Understanding Automated Fire Flow Results

Running a Criticality Analysis

Product TechNotes and FAQs

Haestad Methods Product Tech Notes And FAQs

[[General WaterGEMS V8 FAQ|General WaterGEMS V8 FAQ]]  

External Links

Water and Wastewater Forums

Bentley Technical Support KnowledgeBase

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