Anyone that uses the CPT acknowledges that when dealing with data interpretation Dr. Robertson's published research is always the basis for such a task. Since first published, the non-normalized SBT chart is used by many users to retrieve information about soil type behavior, although the successor SBTn chart (normalized SBT) is known to be more reliable.

Dr. Robertson constantly listens to CPT users so he decided to update the original 1986 chart so that it will be more directly comparable to the normalized one. The obvious advantage of the SBT chart is that it can be used real time. The chart is formed using raw CPT data, cone resistance qc and friction ratio Rf. These 2 variables do not depend on previous knowledge of soil unit weight and ground water conditions that are not available during the CPT. By post processing CPT data one may review the SBTn chart and retrieve information on how confinement pressures alter the interpreted profile.

One more time we are extremely honored that Dr. Robertson revealed to us the updated plot so that we can update the software and test its behavior. When CPeT-IT gets the final approval from Dr. Robertson we will immediately release an update so that our users may benefit from this new feature!!!

We wish you all a very Merry Christmas and a Happy New Year!!!!

Now that you have successfully created your typical sections you maybe wonder which value you should propose for some parameter in a single layer. First of all let's go back and discuss a little on how you should assign code names to your layers.

When working with several CPT files in a single project, you are targeting towards to the identification of soil layers that reappear in the various CPT profiles. Some of theses layers most probably will be assigned with an identical code name, for example Sand_1 layer that appears in CPT-01, 06, 08, 09 and 10. Each Sand_1 layer carries information like average values of various parameters but what you probably need is to present single values when talking about this sand layer. CPeT-IT, adopted the methodology proposed in Eurocode 7, to calculate Minimum Characteristic Values. The analysis is performed mainly for qt but the software will present you the characteristic values calculated for all estimations. By examining characteristic values you may adjust and finally propose single values in your final report.

CPeT-IT is all about interpretation of CPT data. Profiles of cone resistance, sleeve friction and excess pore pressure behind the cone tip provide valuable information over the penetration depth, that can be used to summarize soil stratigraphy not only in terms of soil type description but also in terms of mechanical characteristics. After all design engineers care more about a single parameter value rather than a series of values with ups and downs.

The typical geotechnical section module in CPeT-IT provides a way to summarize overall CPT performance in one single plot where cohesive and cohesionless soil types (mechanical behavior based on what the cone senses) are presented in the form of homogeneous layers. Extrapolating soil layers based on qt profile using only a visual inspection is not a difficult task for those with some experience but again this task may prove quite time consuming. On the other hand it is more than obvious that the cone senses changes is soil stratigraphy and captures this information in the variables that it measures. So, using a uni-variate and simple statistic analysis of the cone resistance profile, based on published work by Prof. Campanella, we created a smart tool that may assist in a quick identification of soil boundaries in a CPT profile. Although various complex and computationally "heavy" methods are described and proposed from various researchers, this simple and "light" technique turned out to have quite impressive output results. The procedure was not programmed to be fully automated in order for the user to control all calculation parameters while very quickly can fixate the values and extract the desired profile.

Although CPT equipment has changed dramatically over the years, applicability is boosted over many investigation fields and new interpretation formulas have been derived (and will continue to appear in the future) some things from the past just seem to stand there, waiting silently to be adopted and perform well using our latest technology.

We are very excited to announce the immediate release of our latest CLiq beta version. This version introduces some major updates as well as fixes in the user interface. Changes made so far are listed below:

[+] Added latest procedure proposed by Dr. Peter Robertson (2009), applicable to all soil types
[+] Added two new columns in the results tabular data to present Su ratio (liquified and peak)
[-] New way to prepare overall reports by selecting CPT files to be included (or excluded)
[-] Modified procedure for strength loss calculation according to Robertson (2009)
[*] Fixed an issue in Ic plots when Ic value cannot be defined
[*] Fixed a mouse issue when double clicking inside plots (zoom function was enabled after closing the dialog)
[*] Fixed a bug when selecting CPT's in 2D map
[*] Fixed minor memory leaks

Registered users are strongly recommended to install the version in a different directory than their original copy. The software now is released in the form of an automated installer so please make sure you select an installation directory other than the directory of your current working copy.

If you are interested in working with this version please send us an email in order to provide you with the download link.

Well, we have just finished coding the next update for CPeT-IT and we are now in the final stage of testing the software. A major addition to this version is the ability to display penetration depth or elevation data on the Y axes of the plots.

Over the past few months we got several requests for this feature so we are very excited to include it in our next release.

In order to correctly display elevation data, users first need to define Ground Elevation in the Calculation Properties dialog for every CPT file in their project. The Project Properties dialog now displays an option where you can select the penetration depth or elevation for the vertical axes. All plots in the software will display the elevation data but tabular results will present penetration depth for easy understanding of the calculations. So, for example if you are designing a typical section, qt plot will display elevation but depth data should be entered based on penetration depth (holding SHIFT and left clicking on the qt plot the software will put the correct penetration depth on the From depth field). Several explanations regarding depth value are also included on the reports as footnotes.

If you have previously fixed Y axes then changing the display type of the vertical axes may result to empty plots so always set Y axes to automatic before making this change.

We really hope that you will enjoy this new feature!