LIQUEFEXCEL USER MANUAL

Excel spreadsheet for Liquefaction Estimation

IntroductionThis document accompanies the spreadsheet program Liquefexecel. The

spreadsheet is a comprehensive liquefaction estimation tool. Some of its capabilities are listed below

1. Can analyze up to 10 different soil profiles. Each soil profile can have up to 10 different soil layers

2. Uses up to 10 different field soil property profiles (STP, CPT,Vs). These profiles are associated with the soil profiles above

3. Can generate up to 10 different liquefaction loading profiles (simplified stress method, simplified strain method)

4. Generates up to 10 different resistance profiles (stress, strain, lab curves)

The most vital feature in the program is flexibility. If the user is familiar with Excel, much of the data can be pasted in, then checked before incorporating into the analysis. Routines for computation are available to the user via Visual Basic for Applications (VBA). The entire program can be accessed through the VBA editor in Excel. Since Excel is the operating environment is used throughout, the user has a familiar operating environment to work in.

Loading the SpreadsheetThe spreadsheet is loaded like any other Excel spreadsheet. Since the analyses

rely on VBA macros, the user must set security to “medium” or “low” in order to run the program. If security is set to “High” you will be able to load the spreadsheet, but nothing will work. If this happens, go to Excel menu Tools=>Macro=>Security (Figure 1) Set the security level to “Medium” or “Low” click OK, Save, Close, then Open the spreadsheet again. This time you should be asked if you want to Enable Macros (Figure 2.) Click on Enable Macros and you are now ready to proceed.

Running the ProgramOnce the spreadsheet is running, the user is greeted with a logo screen (for now

Bartman). Just close the screen with the “X” box and you are ready to start. A small navigation window will appear (Figure 3). Each button on the window corresponds to a specific task. The order of the tasks corresponds to the position of the buttons on the navigation window. Typically one would read the instructions first, enter project information second, soil profiles third, and so on. Once the navigation button is pushed, the navigation window disappears and you move to the appropriate worksheet. Of course you can move to any worksheet you like by the standard Excel methods, the Navigation

Figure 1. Finding Security Setting in Excel

Figure 2. Enable Macros in Excel

window gives some convenience and will also check your worksheet for errors before you leave. Once you move to a new worksheet, to get to the navigation window, simply

click the “Done-Navigate” button and the navigation window will re-appear.

Instruction WorksheetThe instruction sheet gives a brief introduction to the Liquefaction spreadsheet. It

is also used as the default destination for any features still under development.

Project Information WorksheetThis is where the user would enter pertinent project information. The information

is not carried to any other worksheet since it is not needed for calculations. However, information from this sheet is used when a report is generated.

Soil Profile WorksheetThis is where standard soil information is keyed in. The user may copy

information from other spreadsheets or import information from a text file, just as in any Excel spreadsheet. One must only consider the fundatmental layout of the data sheet and remain consistent with the format. Inputs include: Soil profile number, a comment line

(usually Boring number or "Interpreted" use any word or brief statement you like. This description is used later to help jog your memory about which profile you are using. Other pieces of information include start and end depth, number of soil layers, depth to groundwater, and unit weight of groundwater (saltwater or freshwater). For the number of soil layers specified, the user must then fill in the remaining information.

Once the information is complete, click on the command button labeled "Accept Changes" and the program will check to insure you have correctly entered your data. This check is to eliminate obvious errors or impossible logic such as unit weights equal to 300 pcf or a layer that starts at 20-ft depth and ends at 10-ft depth. More subtle errors are beyond the scope of this (and any) software.

The user may generate a profile either manually or automatically by clicking the "Add Profile" command button. Once clicked, the program prompts for which profile to copy and produces a replicate profile. The user can then go in and manually change values in the profile. The values may also be "calculated once" values such as an average of values from a different profile. Once the profile is manipulated (say by deleting a previous profile) only the value remains, the formula is lost. While such formulations aren't common for soil profiles, interpreted profiles may require formulas. Field profiles (discussed next) can also make very good use of small formulations to, say, take an average of blow counts for a given layer or increase all cone tip readings by a factor of 1.2.

Figure 3. Navigation Form Window

Field Profile WorksheetField information is entered as data pairs of depth and blowcount, tip resistance or

shear wave velocity. Note that the field data does not have to exactly correspond to soil profile data, but must be associated with a soil profile to produce meaningful results later.

Once again the user can automatically generate the profile by copying a previous one or manually generate one by typing or cut and pasting the data set. If you choose to paste in the numbers, be sure to enter the appropriate value of "Num Data Pairs" so the software knows how many were entered. A maximum number of 100 data pairs can be used for one profile. Calculated field values are linearly interpolated between the field data pairs

Load Profile WorksheetThe user may choose from three different ways to compute cyclic loading levels.

Either a stress approach (Seed & Idriss), a strain approach (Dobry et al) or a one-dimensional analysis (not implemented). If the user wishes to estimate settlement via Castro's method, the strain approach is used on this sheet. Generating load profiles follows the userforms as they come up. Combo boxes restrict the user to pick only those entries which are relevant to the analysis at hand.

Relevant information include

If you get a message similar to that shown in figure 1. You must do the following: