Hello Dr. CEE, LOL, “… [the CPT table in the example] is rather too clean for reality…”. Thank you for highlighting the frequent pitfalls and blunders in the video; these is priceless and it helps a lot to be aware of them. Yep, the CPT equipment does kind of feel like some form of a “prototype” pile is being pre-driven on site. Question: Can the CPT be used to estimate the pile resistance in any kind of soil stratum including in clay soils? Are there certain ground conditions or other soil characteristics that would make the CPT less accurate or less ideal? 13:20 In my region, and on one of the projects which I have worked on, the design and subsequent construction of the piles was treated as a “specialized design and build service”. The engineer was only required to provide the supports layout and the reactions (from the structure) at each of the support points showing the values for which the piles should be designed to resist. The “piles company” use the reactions provided by the engineer as the design loads on the piles; that plus the site geotechnical report and any other tests that the “piles company” required to design and to suggest piles types, sizes, and configurations which the “piles company” can be able to provide to resist the required reactions from the structure. When a design is accepted and the pile caps details are shared and agreed between the engineer and the “piles company”. The “pile company” finalized the design and they subsequently carried-out the actual construction of the designed piles on site. The design liability, and performance of the constructed piles lie with the “piles company”. Interestingly (although unfortunate as it was in that particular project), the pile load test results from the testing of the finished constructed piles (prior to the construction of the pile caps and of the structure) in that project showed the tested piles to have failed and to be inadequate to carry the required reactions loads. Based on the failed pile load tests results, an independent service provider was contracted to check the piles designs and tests on the completed piles. It was confirmed that the piles were inadequate and strengthening measures were explored and agreed. Those strengthening measures were eventually implemented at the cost of the “piles company” ……. I have enjoyed this video and I am looking forward to other videos by the CEE Keep well and kind regards, DK
Hi there Engr. DK, ooooh yeah.. if you take any soil investigation report (without post-processing, raw data) you would see how zig-zaggy the values are. I had to mention this and also mention how to interpret those results. Of course, the video is not about interpreting CPT test data, but I still need to mention it as part of the video, coz I cannot just show that everything is easy and nice and clean when it is not. Yes, the CPT test can be used to estimate resistances even in clay. This will be covered soon, but here is the reference and page for you if you want to read ahead: Principles of Foundation Engineering (Braja M.Das) page 578 subtitle: Correlation with CPT Same here in regions I worked in (Germany and Bahrain). You just provide the reactions of the supports from your structural model and layout in a table (Serial, X coord, Y coord, 6 reactions) and they do the rest, including carrying the responsibility. So what you mentioned is also what I have seen before. Not only direct liability, there is even the concept of "Opportunity Cost of a Choice". Because, when something goes wrong in piles, not only will there be a direct effect in terms of time and money wasted on using more costly light weight alternatives, oooooh no, there is even more. The owner may give up 1 story in the structure because of this, which means he lost the rent (let's say it is a residential building for lease). This means that the pile company has to "buy" the story he lost. Of course, it is not a strict "buying" and there is a lot of litigation and lawyers involved, but this is one major thing. Also, companies have insurance policies, so now another fight ensues between the pile dudes and their insurance company. Was there a gross negligence? How much does it cover. Oh.. sorry I went down this rabbit hole - again -. But I love the points you raise and I try give holistic views for you and future viewers. I hope I have shed light on the ideas you actually provided. Regards, CEE
@@CivilEngineeringEssentials Thank you for the reference. Also, the CEE videos have already softened the subject and this makes reading the reference materials and book that much easier. It is very good to know that there are similarities in pile procurement approach from other regions as well. I don’t mind the rabbit hole; I find the liability discussions to be enlightening. I personally consider liability for consequential damages to be a muddy subject which often blurs the lines of objective limitation of liability. I guess this is one reminder that the engineering profession exist in the same opportunistic world. Kind regards, DK
Sir, thanks for your professional guidance, can you please make the pile design based on real time project which consists of almost 5 ~ 7 layers of different soil/ rock and effect of water level also. thanks again for this channel.
