A lot of our clients ask about the differences between LiqIT and CLiq software and which one is best suited for their needs. The answer is very simple, if you are using CPT data for soil liquefaction analysis then CLiq is the software you need.

CLiq was developed under the close guidance of Dr. Peter Robertson having in mind specific features of the CPT that can be used to provide a more advanced analysis. Such features include the transition layer detection algorithm and evaluation of cyclic softening in clays. Several calculation parameters are fully customizable while extra care was given to the user interface and analysis plots. With CLiq you may change the plot scales, zoom in or out the plots, apply common scale values to all CPT files in a single project etc. Numeric results for the whole calculation procedure (from interpretation to the calculation of Factor of Safety) are presented in tabular format that can be easily exported for further manipulation.

The liquefaction assessment method used in CLiq is the one recommended by NCEER 1998 (also known as the Youd et al. 2000 method) which provides concise results regarding the estimation of vertical settlements and lateral displacements.

With CLiq you may also create a 2D representation map of the Iwasaki Liquefaction Potential Index (LPI) or vertical settlemens. You may perform a parametric analysis based on a range of values of earthquake magnitude and peak ground acceleration or just preview summary reports for LPI and settlements. CLiq also has the ability to read and import CPeT-IT (a great companion software) project files.

Having the above in mind we assume it is clear that for CPT data, CLiq is far more advanced than the CPT section of LiqIT. Go ahead and give CLiq a try, we are sure that you will love it!!!

Link: http://www.geologismiki.gr/Products/CPeT-IT.html

We are very excited to announce the immediate release of CPeT-IT v.1.6.0.30. Changes made are listed below:

[+] Added option to check and update the application online
[+] Added new WGS84 coordinates property for creating Google Earth placemarks
[+] Added ability to batch import XLS files from XLS import dialog
[+] Added zoom direction property for current project
[+] Added a simple bearing capacity calculation module
[-] Updated procedure for the calculation of stress normalization for Qtn (based on recent reccomendation by Prof. Peter Robertson)
[-] New CPT file manager
[-] New formulas for the calculation of Constrained modulus M (applicable to all soil types), Go, Es and other soil properties
[-] New settlements calculation module (applicable to all soil types)
[-] Quick preview now displays SBTn plot
[-] Some minor visual enhancments
[*] Fixed a bug when importing XLS files without u2 data available
[*] Fixed a small issue when calling the geotechnical section module
[*] Fixed a bug in the normalized qt plot (holding the SHIFT key the software was pointing in the wrong column in the tabular results)

If you are upgrading a previous version of CPeT-IT please remember to recalculate all your project files in order for the new changes to apply.

Originally, Robertson and Wride (1998) suggested a normalized cone parameter to evaluate soil liquefaction, using normalization with a variable stress exponent, n. Calculation of the stress exponent, n was based on a simple procedure that later was updated by Zhang et al (2002) and is summarized below:

When Ic lower or equal to 1.64 use n = 0.50
When Ic greater or equal to 3.30 use n = 1.00
Other cases use n = 0.30*(Ic - 1.64) + 0.50

Based on recent recommendations by Prof. Peter Robertson the normalization procedure for the calculation of the stress exponent n, is updated as follows:

When Ic lower or equal to 1.64 use n = 0.50
When Ic greater or equal to 2.95 use n = 1.00
Other cases use n = 0.381*(Ic - 1.64) + 0.50

Prior beginning the iterative procedure a check is made regarding the vertical effective stress at the time of the CPT (to take into consideration the fact that at high pressures dilatancy is suppressed and grain crushing predominates):

Set n = 1.0 when effective_stress > 1125 - 381 * Ic (in kPa)

The next releases of CPeT-IT and CLiq will include the new procedure.

More and more users these days get familiar with Google Earth and discover new ways to visualize their data over real world satellite images. As almost all CPT contractors provide information regarding the location of a Cone test on the ground using GPS equipment, we thought CPeT-IT should be able to deal with these coordinates in order to create a special file (KML file) that Google Earth recognizes as a placemark.

We introduced a new property for each CPT file, where you may import your real world coordinates. These coordinates should be compatible with the World Geodetic System WGS84 and can be in a format of decimal degrees or degrees, minutes and seconds.

A new export command has been added and after selecting a target directory, the software will create KML files for all selected CPT's in your project file. After the export procedure is over you may open Google Earth and from the File menu choose Open to import your KML files (or just drag and drop them in the application).

We really hope to find this new feature useful for your CPT projects!

My home town Serres, successfully organized the International 6 Days Enduro - ISDE 2008. Now that the race is over and all the dust is gone we can be very proud that we did our best to hold an event of Olympic proportions!

To all fellow bikers out there, be safe and may you always stay on your bike!

Prof. Peter Robertson is working on an excellent update regarding the interpretation of CPT. New correlations to various soil properties are developed based on a unified approach for all soil types.

We had the time to implement some of the new formulas in CPeT-IT and test their performance using real data. We are very excited with the new approach to estimate 1-D constrained modulus M from CPT which is now used to perform settlements calculation for the whole CPT profile. We performed comparison tests with a number of case histories and the new procedure provides excellent estimates. Taking one step further, users will have the option to perform an additional calculation for settlements due to creep effects (secondary settlements) for cohesive soils, if wanted.

The new version is almost ready but work is needed to update the documentation and the associated CPT Guide. However, since the new settlement procedure provides significantly improved results, the next updated version of CPeT-IT will be released early before all the documentation is completed.

Stay tuned to Gregg Drilling, Inc. for the next Robertson's remark and to our web site for news regarding the next release.