PDI TOMO Quick Start Guide - Pile

After a TCX file has been loaded into PDI-TOMO, either automatically after exporting from CHA-W ormanually by selecting it from the ‘File’ menu, you are ready to begin the tomography processing. If thefile was opened automatically via exporting from CHA-W – and the ‘Auto Process’ button was checked –processing will begin immediately. If you did not select ‘Auto Process’ – or you opened the file manuallyfrom the PDI-TOMO ‘File’ menu – then you must manually begin the process.To manually begin the process, select ‘Start’ from the ‘Processor’ menu. Tomography is a calculationintensive process so completion may take a few seconds, or longer, depending on the amount of data. Astatus bar will be present during the processing phase.Once tomography processing has completed, the results will be displayed as either a 3D view of theshaft or as a series of slices at various depths initially selected automatically by a default algorithm. Theuser can toggle between these two primary views, 2D slices and 3D shaft, via the ‘View’ menu (‘Slices’or ‘3D’) or via the associated toolbar buttons.SLICE VIEWThe slice mode view displays an effective area graph on the left and four automatically selectedhorizontal cross-sectional slices on the right. The automatically selected slices are part of the seamlessone-step operation to go from CHA-W to PDI TOMO. These slices can easily be re-defined by the user asexplained in sections below7

Effective Area GraphIn PDI-TOMO, the principal measure of determining the quality of concrete at a particular depth is‘effective area’. The tomography process results in a finite number of discrete three-dimensional cellsdistributed over the entire volume of the pile, each with its own calculated wave speed value. When aslice is created at a specific depth, those three-dimensional cells become two-dimensional cellsdistributed across the cross-section.Effective area is defined as the ratio of the cross-sectional area (number of cells) of the slice with wavespeeds greater than a user-defined threshold to the total cross-sectional area (total number of cells).The user-defined threshold is called EWS (Effective Wave Speed).For example, if all cells in a cross-sectional slice are above the user-defined limit (EWS – or EffectiveWave Speed), then the slice has 100% effective area. If 80% of the cross-sectional area has wave speedsabove the limit and 20% below, the effective area is 80%, and so on.In addition to the effective area wave speed limit, EWS, there are four other wave speed values that willbe discussed briefly.SWS – Source Wave Speed.8

This is the average wave speed value of the profiles exported from the Cross-Hole Analyzer. Thisaverage value excludes potential defects and is adjusted for diverging tubes, calibration errors, cableslippage, etc. as described above in EXPORTING FROM CHA-W TO PDI-TOMO. This is an image of a CHAW profile that has been adjusted:A slope of zero indicates that any non-parallel characteristics of the profile have been removed and theintercept indicates that the average wave speed (SWS) is 3857.1 meters/second.SWS is equivalent to the average wave speed entered by the user when exporting to TomoSonic. Sincethis value is now carefully and accurately calculated by CHA-W, user entry is no longer required.The source wave speed is a critical component required to begin tomography calculations and itrepresents the nominal wave speed value of good concrete in the pile for a single two-dimensionalprofile scan.AWS – Average Wave SpeedThe average wave speed value (AWS) is the equivalent average wave speed (good concrete only) of thethree-dimensional cells after tomography processing.From a theoretical point-of-view, both the source wave speed and average wave speed should have thesame value. From a practical standpoint the amount of input data available for tomographic processingin Cross-Hole measurements for deep foundations applications is typically below the optimum (whencompared to use in medical and other highly-precise work) and this relative lack of data results in slightdifferences between the two values. However, the difference is generally less than one percent andshould not be a concern to users.AWS is a calculated value and cannot be changed by the user.HWS – High Wave Speed9

Since the majority of wave speeds in any given pile will be centered on the average (AWS), and defectswill have wave speeds that drop well below the average to varying degrees, we want to define a rangeof wave speeds that will correspond to the wave speeds of interest in our analysis. As a default, wedefine the high end of this range as equivalent to the average wave speed (100% of AWS).LWS – Low Wave SpeedLikewise, we define the default low end of the wave speed range as 77% of AWS which corresponds to a30% increase (e.g. delay) in first arrival time from the average.The values of both LWS and HWS can be re-defined by the user as described below in Wave SpeedLimits.Wave speeds between LWS and HWS are displayed in the slices as a continuous spectrum correspondingto the visible light spectrum from red to blue (e.g. low to high wave speeds respectively).The three horizontal white lines on the color spectrum scale correspond to HWS (highest line), LWS(lowest line) and EWS (center line).EWS – Effective Wave SpeedAs described above, EWS is the threshold value used for effective area calculations. Any value belowthis threshold is considered potentially less than desirable concrete. EWS must be a value between LWS10

and HWS. The effective wave speed limit currently defaults to 95% of AWS but, like LWS and HWS, itcan be modified by the user as described below in Wave Speed Limits.The value of EWS is important for interpretation of the tomographic analysis results but the use of adefault value of 95% should not be considered an absolute limit, below which concrete is considered‘defective’ and above which it is considered ‘good’. Pile Dynamics, Inc. makes no recommendation onwhat value should be used for EWS and leaves this up to the engineering judgment of the user.IMPORTANT NOTE: Effective tomographic analysis requires much more source data than is typicallyavailable in CROSS-HOLE measurements. The calculations in PDI-TOMO have taken this relative lack ofdata into consideration and optimizations have been added. Optimizations are currently moresuccessful when a minimum of six access tubes per shaft are utilized. We continue to develop improvedoptimizing algorithms for shafts where a lesser number of tubes are used.Evaluation of tomographic results from a civil engineering standpoint is beyond the scope of this guide.This guide provides only the basic information required to operate the program. Please contactEngSupport@pile.com if you require technical support for tomographic results evaluation.Wave Speed LimitsAs noted above, the Source Wave Speed (SWS) and Average Wave Speed (AWS) are calculated valuesthat cannot be changed by the user. The Effective Wave Speed limit (EWS) and the High and Low limits(HWS, LWS) can be changed as described below. Setting each of these limits to appropriate values iscritical for proper analysis and presentation of the results.The variable wave speed limits may be changed via the Wave Speed Limit Editor dialog shown below.Select ‘Wave Speed Limits’ from the ‘Edit’ menu, or click on the green tool bar button11.

HWS is initially set to 100% of AWS, LWS to 77% of AWS and EWS to 95% of AWS. These values can beadjusted according to the judgment of the engineer.After the desired wave speed values have been entered, click ‘Apply’ to apply the values to the currentdocument while observing the changes and without closing the editor, or click ‘OK’ to apply and closethe editor. Click ‘Cancel’ to leave the current values intact.HWS and LWS SlidersIn addition to the method described above, HWS and LWS may be changed by means of ‘slider’ controlsin the left pane when displaying slices. When you drag either of these sliders up or down the display ofthe slices and the color spectrum scale will change accordingly.The sliders are initially locked to prevent inadvertent adjustment of carefully selected LWS and HWSvalues. In order to use them you must uncheck the boxed labeled ‘Lock’ located directly below thesliders.In order to obtain a two color display, LWS should be moved to its highest position – where it matchesEWS – and likewise, HWS to its lowest position where it also matches EWS.EWS has no equivalent slider control due to the large number of calculations based on the entire volumeof the pile that are required whenever EWS is changed.TWO-COLOR ModeIn the lower left corner of the Wave Speed Limits dialog is a check box labeled ‘Two Color.’ When thisbox is checked, EWS acts as a simple binary threshold. All values above EWS will be displayed as blueand all values below as red. In the two-color mode, HWS and LWS will be set equal to EWS and theentry controls for those two values are disabled as shown in the figure below.12

SlicesAfter tomography calculations have completed, the processor automatically determines the depths ofup to four cross-sections where the effective area has a local minimum. These slices are useful for quickevaluations but in most cases you may want to re-define, or at least make adjustments to, the defaultslice locations – including the number of slices which is selectable from 1 to 4.The first method of adjusting a slice depth is to simply click on one of the preselected depths(represented by red or yellow dashed horizontal lines) in the effective area vs. depth graph and drag itto a new depth location. This method works well for coarse adjustments but for finer control right clickon the slice (after dragging it to an approximate location) in the “Effective Area” chart and select ‘Zoomhere.’ The effective area scale will change to zoom in on the slice at the depth where you right-clicked.After you have made fine adjustments to the depth, right-click again and select ‘Cancel zoom.’ Repeatthis procedure for each slice as required.A second method is to open the slice depth editing dialog window (shown below) and manually enterexact depth locations.13

To open the slice depth editing dialog window right-click anywhere in the effective area vs. depth graphand select ‘Edit slice depths.’ As you enter a depth in one of the edit boxes to the left, thecorresponding depth marker (yellow dashed line) in the graph changes in synch. If the ‘Zoom’ box ischecked, the graph also zooms to the correct location as depths are entered.Auto-SliceThe Auto-Slice button duplicates the functionality of the auto-slice method used by the tomographyprocessor. Whenever tomography processing is started, the last stage is always the selection of defaultslices and this button allows you to return to those defaults after you have made edits that you do notintend to keep.Slice Mode – “Area” and “Weighted Area” (W.Area)Since the effective area calculation is based on a simple threshold level there are some subtle issues thatarise when attempting to detect the relative magnitude of multiple defects. For example, if 3200 m/s isthe EWS limit and you have potential defects at two depths – each with 50% of the area slightly above3200 m/s but one defect with the other 50% of the area at 3000 m/s and the other defect with 50% ofthe area at 2000 m/s – then both of these slices are considered equivalent according to the effectivearea calculation.But the slice with 50% of the area at 2000 m/s is arguably more serious than the one with 50% of thesection at 3000 m/s. The weighted effective area calculation takes into account not only the percentageof the cross-section below the limit but also how far below the limit it is.The weighted effective area is currently not used in auto-slice calculations but intended only as anadditional tool for the user when manually selecting slices.3D SHAFT VIEWThis view presents the shaft in 3D mode along with a single cross-sectional horizontal slice in the lowerleft corner. The slice will initially be set to the depth of the currently selected slice in the left pane andwill track changes made to the selection. Select ‘3D’ from the ‘View’ menu or click thebutton to show the 3D Shaft View.14toolbar

Right-clicking with the mouse in this view will bring up a menu with various options for manipulating theimages as explained below.FixedThis is the standard mode for viewing a shaft in 3D. It provides several features useful for locating andinspecting various areas of the shaft.15

To rotate the shaft, click the left mouse button in the background area of the view to the left or right ofthe shaft.To drag the shaft vertically, move the mouse near the center of the shaft until the cursor changes to ahand, then click and drag up or down. Hold the ‘Ctrl’ key down for faster dragging.Use the mouse wheel to zoom in and out.To change the depth of the slice shown in the lower-left corner of the view, navigate to the depth ofinterest on the shaft, then left-click on shaft at that depth while holding down the ‘Alt’ key (or doubleclick at the location). The slice in the lower-left corner will now display the slice at the depth of interest.Free“Free” mode allows free rotation of the shaft during visual examination by the user.Show Tubes, Depth Scale, VolumeThe three main components of the shaft view, the ‘volume’ representing the tomography data, thetubes and the depth scale can be turned on or off from the “show volume”, “show tubes”, “show depthscale” respectively (as shown in the menu on figure above). .Volume Aspect RatioSince the ratio of a typical shaft’s length to its diameter is relatively large, PDI-TOMO presents a methodof reducing this ratio to aid visualization. When a volume aspect ratio of ‘1’ is selected the shaft will bedisplayed in its actual proportion. Selecting a value of ‘2’ for the ratio will expand the diameter by afactor of 2. Likewise with ‘4’ and ‘8’.You also have the ability to enter a custom aspect ratio if one of these standard values is not sufficient.MISCELLANEUOUS MENU ITEMSEdit – LogoThe printed report page includes space in the upper-right corner for your company’s logo (.jpg, .png,.bmp, etc.) which can be selected by means of this menu item. This logo will also be stored in eachdocument you create so it is recommended that you have a pre-selected logo which has been optimizedfor size. We recommend that the image file be no more than 20 kB.Edit – Job InformationIncludes various additional items that will appear on the printed report such as company name, projectname, pile name and test date.16

There are also entries for pile length, diameter and cage diameter which are for reference only and donot affect calculations in any way.View – OpenGL InformationInformation obtained from the operating system regarding the state of your computer’s graphicscapabilities, primarily for diagnostics purposes when graphics issues arise. PDI will always request thisinformation when you initiate a support request for any issues that may be related to graphics.Note that the same information is available in the error messages report (see next item) and it ispreferred that you supply the full error report / OpenGL info when initiating a support request.View – Error MessagesThe PDI-TOMO software makes an attempt to log graphics-related errors for diagnostics purposes. Asnoted above, if you have issues with graphics and request support, please send a copy of this report toPDI along with your request.Options – UnitsPDI-TOMO is capable of displaying all data in either Metric or English units regardless of the units systemused originally during data collection or report generation in CHA-W. Initially, PDI-TOMO usesinformation from your Windows Regional Settings to determine the most appropriate units, but youmay change this at any time by means of this menu item.Note that internally all calculations and data storage in PDI-TOMO and CHA-W is in MKS units. Englishand Metric are for display purposes only.Options – Background ColorYou have three options for background color when displaying a 3D shaft image or slices: black, whiteand gray.Options – TranslationsCurrently under development and planned for a future release, PDI-TOMO has limited support fordisplaying some of the screen text translated to the user’s language of choice rather than in English.This item will turn the translations on or off as desired. It is inactive in the initial release of PDI-TOMO.Options – Load Most Recent FileIf this item is checked, PDI-TOMO will load the most recent file you had open each time it runs – withthe exception of being called from CHA-W for auto-processing.Help – License InformationDisplays the current status of PDI-TOMO’s license and facilitates updates when required.17

Help – Check For UpdatesWill connect to www.pile.com to determine if a more recent version of the software is available. If it is,an option will be provided to download the more recent version. This feature will be active only if theinstaller has place the version checker dll file in the expected location. If it is not active, please contactSoftwareSupport@pile.com.Help – Quick Start GuideView this Quick Start Guide. It will be active only if the guide has been placed in the expected locationby the PDI-TOMO installer.PRINTINGPDI-TOMO includes standard Windows printing features accessible via the ‘File’ menu or the Printbutton on the toolbar. The general layout of the printed page can be viewed on the screen by means ofthe ‘Slices (Print Mode)’ option on the ‘View’ menu. The print mode can also be selected via tool barbutton labeled ‘OUT’for output.Like most Windows programs, PDI-TOMO will use the system default printer unless another printer isselected in the Printer Setup dialog ‘Print ’ which is accessible via the ‘File’ menu. The selection of an18

alternate printer normally lasts only for the period in which the program is running. When the programis closed and then re-opened at a later time, the selected printer will revert to the system default.If desired, PDI-TOMO will remember your preferred printer and always use it instead of the systemdefault. To enable this feature select ‘Printer’ from the ‘File’ menu and check ‘Remember Selection’.Note that using the Windows system default printer is usually the preferred method. If you typicallyalways use the same printer for all applications it is recommended that you set the system defaultprinter via the Windows Control Panel ‘Devices and Printers’ and leave PDI-TOMO’s Printer selection setto ‘Use System Default’.19

CHA-W & PDI-TOMO LICENSING Starting with CHA-W version 2016.017 and the initial release of PDI-TOMO version 2016.1, PDIs new uniform software licensing scheme takes effect and each of those programs will have to be licensed before their first use — even if you already use a previous version of Cross-Hole Analyzer (CHA-W). PDI-