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### This Post Has 43 Comments

1. Mark

May I please know what the u0, and u1 input parameters are when trying to input custom soil parameters? Thank you

1. u0 and u1 are user defined parameters. You can use them for any soil parameters you defined.

2. kaisar

Hi Yong, how to renew licence, please ?

3. Phong

I want to ask that when we get lateral ultimate resistance with units of force per unit length, which area of the pile segment should I multiply to get the lateral force at each segment of the force-deflection curve ?

1. Hi Phong, the lateral resistance with unit of force per unit length (kN/m) is from the lateral pressure (kN/m2) x pile width (m). To obtain the lateral force eat each pile segment, use the lateral resistance (kN/m) x pile segment length (m) = force (kN).

4. Maria C

Hello! Is there any instructions for using the “Custom soil by function” option?

1. Hi Maria, when you choose the Custom soil by function, you should be able to see the default function. The parameters are typical ones such as unit weight, c, phi, e50, k, and two user defined parameters u0 and u1. The program will call the function with a certain deflection y (m or ft) and the return value will the the linear force P (N/m or lbs/ft). Therefore this function defines the P-y curve based on the input parameters. You can try to use it with linear relationship and make it more complex gradually. Please let me know if you have any questions.

5. Jhean

Excelente Programa ,felicitaciones por el desarrollo y muy agradecido. Me gustaría realizarle una consulta : Si bien se sabe, existe diferentes metodologías para el calculo de la curva P-Y. Con referencia a los suelos granulares (Arenas), están los métodos de Reese, Cox, & Koop, 1974, Instituto americano del petróleo API RP 2A, entre otros. ¿Es posible utilizar algunos de estos dos métodos para estratos que están constituidas por arenas y gravas o su aplicación de estas metodologías es solamente para arenas?

1. Hi Jhean, I would say you can use either curve to simulate your sand and gravel. But, if you don’t have test data to justify your parameters, you have to use your own engineering judgement to select the parameters. If you notice that your soil behavior is significantly different than those curves, you can provide you own curve with a JavaScript function, which can be easily implemented in PyPile.

6. Ali

Hello, I have been using this great software, but when I wanted to write a report, didn’t find enough information about how the calculations were carried out. can you please share how make use of the output graphs by defending how calculation were done. or possibly adding a generate report ribbon. Thank you

1. Hi Ali, the calculation is based on finite element method. The pile is simulated as beam-column elements and the surrounding soils are simulated as continuous nonlinear springs (not individual springs). Regarding the soil p-y curves or nonlinear soil spring stiffness, you can reference “ANALYSIS OF SINGLE PILES UNDER LATERAL LOADING” (Barry J. Heyer and Lymon C. Reese, 1979). Please let me know if you have any questions.

7. Felipe

Hello. In a cemented soil with cohesion and friction, how does it calculate the default k? Is there any reference for this? Besides that, congratulations on your brilliant software.

1. Hi Felipe, I have sent you an email about the k values.

1. Felipe

Great, thanks for this. It helped me a lot.

8. Nick

Hi Yong, Thank you for sharing your software. Is pypile designed to run analysis under seismic load?

1. Hi Nick, PyPile cannot process seismic loading at this moment. I think this is a good topic I should and I will look into.

9. Tom

Hi Yong, I’m a civil engineer working in the US solar industry. Our projects typically have 100k+ driven piles used as foundations to support solar panels.

The loads are fairly small, but the challenge is value engineering the multiple conditions. I’ve been trying to find a way to incorporate a lateral pile analysis into QGIS that could analyze all of the conditions and analyze scenarios to pick the 10-20 most economical piles. Python code can be incorporated into QGIS or a list of all of the piles and input variables (soil depth, loading, etc) could be exported from QGIS and input to a structural program.

Do you have any suggestions? Or are you open to talking further?

1. Hi Tom, you can use your python code generate PyPile input files and then let Python run PyPile with each input file. PyPile can be run in command line mode as “PyPile.exe input_file.pil”.
The PyPile file is in JSON format. It should be pretty easy to generate the input files with Python. Open any of the files and you should be able to figure out the meaning of the parameters.
Please let me know if you have any questions.

1. Tom

Thank you so much, Yong! I added you on LinkedIn… mind if I message you questions there? Or would email be better? Or here?

10. Greg

When using a reinforced concrete round pile, the pypile program seems unable to find a solution if a moment is applied at the top of the pile that fails on the curved (nonlinear) part of the moment curvature diagram.
Also it would be good to have the curvature units included in the curvature axis title on the moment curvature graph. Ability to export moment curvature data to excel file would be helpful.

1. Greg, can you please forward me the data file you mentioned?
Will add the curvature units and curvature data export function.
Thanks.

2. Greg, when you apply 60 kips lateral force and 1364.5 kip-ft moment, the max moment in the pile section is about 1670 kip-ft, close to the max bending moment of the reinforced concrete section (see moment curvature graph). An additional 0.1 kip-ft moment results in an unconverged calculation, since the section cannot balance the load.

11. VW

I have created two almost identical models. The first one only contains a single layer of soil. The second one contains two layers of soil with the exact same soil parameters. The loading, soil parameters and pile properties used in these two models are all the same. However, the results obtained from these two models are slightly different. Can I know why?

Thank you.

1. Hi Allen, can you please forward me the two files you mentioned in the commends by email? Thanks.

2. Hi Allen, this difference is resulted from an incorrect equivalent depth of the sand layer. This is fixed in version 0.9.0.6.

12. Tristrium

Hi. Thanks for a great program.

I am not able to use the reinforced concrete round pile option.

It keeps giving an error of “Concrete strength too low”. This happens on both new models and when I modify anything on old models as well.

When I set up the round pile it calculates the moment curvature graph without any problems.

Is this a bug in the latest release?

Thanks

1. Hi Tristrium, can you please forward me your file by email and let me take a look?

2. Hi Tristrium, thanks for pointing out this issue. It has been fixed in v 0.9.0.5.

13. Tan

Can I model a steel pile with concrete infill & rebar using PyPile?

1. Hi Tan, if you consider the nonlinearity of the concrete and steel, there is no direct pile section setup for this type of piles in PyPile at this moment. Currently only concrete piles with rebar reinforcement are available.
However, if the nonlinear pile bending moment and curvature relationship is available, a user defined pile can be used to simulate the composite pile.
If your pile is rigid enough and pile curvature is not excessively large, the steel pile filled with concrete and reinforced with rebars may stay in a relatively linear elastic stage. In this case, you can simulate the piles with a composite elastic material and a simple round pile will meet the requirement. This assumption will need to be checked though.

14. alan green

Py Pile summary output lists maximum positive moment and shear force and not absolute maximum, why is this.

1. Hi Alan, can you send me a data file explain a bit more about this question? Thanks.

2. Hi Alan, this is fixed. Thanks for pointing it out.

15. CRO

How do I get an English version?

16. BD

Can you describe a little bit on the platforms you use to code this beautiful softwares? They are so good looking.

1. Thanks. The program was written with C++ and Qt.

17. KHY

When i run the analysis for PY curves, the software straight away shut down, May i know why and how to solve it ?

1. Please try version 0.9.0.3. Please let me know if the problem persists.

18. Levy Enore

does PY pile have a geotechnical reduction factor applied? or can we edit the geotech reduction factors?

1. Hi Levy, no additional geotechnical resistance factor is introduced in PyPile. Or a geotechnical resistance factor of 1 is assumed. You can let me know what your case is and see if anything can be done to consider the geotechnical reduction factor you mentioned.