Horizontal Loads on Foundation Wall
Horizontal Loads on Foundation Wall
(OP)
I'm looking at placing a piece of equipment on grade adjacent to a building. This equipment will be placed near (about 4-5' away) from the existing building.
What is the most accurate method for determining the horizontial load distribution on the foundation (basement) wall??
I have a foundations book but it is only calculating the resultant force and it is for retaining walls. My wall serves as a basement and then extend past this as a foundation wall. Hence, I would like to have an accuarte distribution of the forces along the wall.
Thanks in advance
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Andrew
What is the most accurate method for determining the horizontial load distribution on the foundation (basement) wall??
I have a foundations book but it is only calculating the resultant force and it is for retaining walls. My wall serves as a basement and then extend past this as a foundation wall. Hence, I would like to have an accuarte distribution of the forces along the wall.
Thanks in advance
---
Andrew





RE: Horizontal Loads on Foundation Wall
I have the case of the infinite strip load at a distance such way in Mathcad Collaboratory, which has only values varying along the depth in the interface.
Unfortunately I have not it for the finite rectangle in which also would vary along the length of the wall, but to make a sheet to such purpose wouldn't be as difficult starting from the formulation of the stresses for a point load or modifying other sheets.
By the way note that as interesting is then to determine the tangential loads in the wall, that help in stabilization and give the inclination of the resultant in a particular element.
Now a formulation in card OCE 5
Numerator= b x c x s x k
Divisor=
((a+b) x tan ((fi/4)+(pi/2)) - a x tan (fi)) x (a + c))
Unitary push= Numerator / Divisor
a shortest distance in plan of load to wall
b dimension of load perpendicular to wall
c dimension of load parallel to wall
s uniform load per unit surface
k active pressure coefficient
fi angle of inner friction
pi 3.1416
This unitary load affects to the region
in plan
spreading 1 along the wall to 2 along the normal to the wall
(i.e. spreads at 26.66 deg from closest vertices to wall)
in section
from the closest point in the load, draw a line at fi with the horizontal downwards and towards the wall.
The region above gets excluded from loading.
from the farther point to the wall, draw a line at
(fi/4)+(pi/2) with the horizontal downwards and towards the wall.
The region below gets excluded from loading.
RE: Horizontal Loads on Foundation Wall
The book I have only gives the TOTAL reaction so your method should work great for me (load is sitting on sand fill). I have one question on your method......
The angle from the furthest point of the load, (fi/4)+(pi/2); I'm not getting a "good" angle for that. At this point I'm assuming fi=45 deg. When I try to calculate the angle above I'm getting up around 100 deg. That doesn't seem correct because it would never intersect the wall. What am I doing wrong.....fi angle too high??
To everyone:
Based on experience does anyone THINK a 40,000 lb peice of equipment (8'x12'), placed 5' away from a basement wall, will cause the wall to collapse?? The basement wall is 15" thick and doubly reinforced, As= #5's @ 12" and As'=#5's @ 12". Wall is 21' tall, laterally supported at grade and 10' down from grade. My calcs are saying that it will fail....and fail by a longshot!!
Thanks for any advice you can offer. You guys are my structural mentors
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Andrew
RE: Horizontal Loads on Foundation Wall
((pi/4)+(fi/2))
is what there must be in the formula AND for drawing the downwards and towards the wall line. It is the classical inclination for the active pressure wedge. Sorry.
I was thinking in making a Mcad sheet for this since I only copied it, have not checked even the dimensionality.
The K the method uses in the reference is that for the active push, not the at rest.
RE: Horizontal Loads on Foundation Wall
RE: Horizontal Loads on Foundation Wall
What about the FIRST angle in the divisor. Which form should that be in, ((pi/4)+(fi/2)) OR ((fi/4)+(pi/2))??
It makes sence that the angle should be the one for the active pressure wedge, ((pi/4)+(fi/2)), but I'm getting a negative divisor using that one. What does a negative number indicate?? Or is there another error??
Any help would be appreciated. Thanks,
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Andrew
RE: Horizontal Loads on Foundation Wall
RE: Horizontal Loads on Foundation Wall
You are the best!! E-mail is lundy@dmww.com
Thanks for all your help. The building's wall will appreciate it....but not near as much as I will!!
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Andrew