Soil Structure Interaction
I have two questions:
- In the Soil-structure interaction example file, the piles are given small properties ( area and moment of inertia). I searched the help and manual but was not able to find how to model a building on pile supported foundation. Is there any information that can be used?
- Can quake be used to analyze a single pile?
Thank you
Answers
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Hi @BenanZahawi1,
- GeoStudio isn't a pile analysis software. You can use our other software, PLAXIS, to analyze pile foundations. Here is a writeup: How to Model Piles in PLAXIS
- Here is information about analyzing a single pile in PLAXIS: 3D Modelling of a Driven Pile under Axial Loading
I hope these help. Please let me know if you have any other questions.
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Trevor
Thank you.
I understand it is not a pile project and I do use PLAXIS. However, the reason I asked is for the following
a. There is a soil/structure interaction example of a building on piles.
b. The software does have the capability of modeling beams ( in the example )
That is why I had the impression that single pile/ pile group can be modeled
What is the purpose of soil/structure interaction example if the software should not be used? A bit curious
Thank you
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In the writeup for that example, it states, "QUAKE/W is not intended for analyzing the dynamic behavior of structures for the purpose of designing the structure itself. Estimates of the building rigidity can, however, be included in an earthquake ground response analysis. This example illustrates some modeling techniques used to include the effects of a structure, including the mass of the structure, in a QUAKE/W analysis. This example also demonstrates that the structural elements in QUAKE/W function in accordance with expectations."
I assumed you meant calculate pile capacity when you said analyze a pile, which GeoStudio doesn't do. Using GeoStudio, we can analyze the effect of piles on slope stability, which you can see in the Slope Stabilization with Piles SIGMA/W example file. You can plot the axial, shear, and moment forces in the pile using the graphing tools in SIGMA/W.
There are also other uses for soil structure interaction in GeoStudio which can be seen in the Braced Deep Excavations in Soft Ground, Tie-Back Wall, and Underground Tunnel Excavation SIGMA/W example files.
I hope this helps. Please let me know if you have any other questions.
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Trevor
Thank you and apology for going back and forth on this.
With regards to other Geostudio products, I understand that and have used them. I was actually interested in Quake/w specifically, not to design the piles but just model a soil/structure interaction. Since Geostudio is a plane strain software, I was wondering how pile properties can be input since ( my assumption) is that the actual pile properties have to be modified to reflect the plane strain. PLAXIS 2D does it through embedded beams for example.
You mentioned the structure rigidity can be input, and that is exactly what my question is ( structure as well as pile), how can it be done? The software manual does not include this or I have not seen it
Thank you
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You are on the right track, Benan. Since GeoStudio is a plane strain software, cross-sectional area and moment of inertia need to be input per unit thickness. This is specified in the help menu under Define Structural Beams.
The reason I recommend PLAXIS is because the 2D nature of the plane strain analysis does not allow for the consideration of a singular buried entity (that could only be considered in a 3D model). Thus, it implicitly requires that any 2D embedded beam would represent a continuously spaced set of piles in the out-of-plane direction with a pile-to-pile spacing value not too large compared to the pile diameter, such that an average soil displacement as provided by the 2D soil mesh between piles would remain an acceptable assumption.
PLAXIS 2D and GeoStudio are the same in this case. However, PLAXIS can also perform 3D static and dynamic stress-strain analyses to analyze a single pile, whereas GeoStudio cannot.
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