sorry for the confusion, the support at the base is vertical only, which makes it a roller.
Also, the piles are embedded into rock (sandstone), in this case, would the soil stiff still less than the piles'?
I don't have access to the model at the moment but I have drawn some sketch. Hope this helps.
Please note that the model is in 3D.https://files.engineering.com/getfile.aspx?folder=858efa12-65d8-4c3e-8770-cc4a72a2dab9&file=Capture.JPG
EZBuilding
Thanks for the answer. I'm not sure if I understand the last part. Can you explain a bit more? And no I am not putting any external restraints at the pile cap, as I assumed soil at the level is fill. I do put soil spring along the pile elements.
Piles will be socketed into a rock layer. I agree with what you said and realize it is the vertical stiffness that is changing the result.
Previously when we modeled the piles with longer length, we put the tip support condition as pin. My understanding is that eventhough the tip is pinned...
Hello Guys. I have a quick question here.
I have a question about pile lengths in analysis model in particular. I'm doing the substructure part of a bridge design. For the piles, I'm responsible for determining the reinforcement, but the pile length, anchoring, etc. are handled by a...
Tomfh
Thanks! I have read through that post. The comment by KootK on 7 May 21 was what I was thinking about, good to know that someone agrees. But I still wonder what designers do in practice when have to deal with this asymmetry, especially in a more complicated cases. Because in that post...
Hi I'm currently self-studying the strut and tie method. I get the general concepts and they all make sense. But then I started noticing how sensitive the validity of the strut and tie model is. For example:
In a very simple strut and tie example I have seen all over the internet (see attached...
Sorry for the late reply, been very busy lately. Thanks for your comments.
Just one question still isn't clear: In downstand grillage, can the results be used directly? Or do I need to manually combine the action between transverse and longitudinal element?
Link
I started a topic to ask about transverse member property in grillage analysis and how accurate the method is. Please click the link above to see the discussion.
Some questions I still have are:
1. What is the difference between the result from plane and downstand grillage? My understanding...
HTURKAK
Thanks, clear on the differences.
So, in general, grillage with rigid link is better, right? Do you prefer to model it with rigid link if you had to design a bridge yourself?
retired13
here are some sketches, hope this helps! (sorry for bad drawings[tongue]) BTW, we usually define local x axis along the direction of line element, ergo torsional stiffnesshttps://files.engineering.com/getfile.aspx?folder=17fc7532-3205-411b-9c9e-e31ee9a5b0ad&file=trans_grillage.pdf
HTURKAK Thanks for your answer.
still some questions here.
1. If I lift the transverse element up (slab) to represent the actual height, isn't that considered as "Downstand Grillage/3D Grillage". In this case it makes sense. But many people prefer to use 2D grillage. my question is : is it...
Hi recently there has been a question occured in my mind. When we do grillage model, let's say I girder bridge with cast in-situ deck, we assign the properties of I section plus those of deck slab with its appropriate effective width.
For transverse member, we simply assign the property of slab...
