Offset Surcharge - Bousinessq History of Modifications
Offset Surcharge - Bousinessq History of Modifications
(OP)
Can someone clarify the history of exspirements or modifications to Bousinessq equation for offset surcharge?
I have been researching this topic the last week pretty extensively and will have some questions based on the actual calcs that I will post in a different thread.
I'm curious as to why the same equation is used with credit given to different people. I'm curious of each persons contribution.
Point Load modification: Terzaghi (most commen), Spangler and Midlin.
Line Load modifications: same as above.
Strip Load: Credit seems to be given to Tang. However it does not appear that this calculation is modified. The equation is given in Poulos and Davis and there is no comments that it is modified but some say it is modified by Tang. Are there any modifications to the strip load equation (except for the factor of 2 debate)? If it is not modified I should be able to discritize a strip load into a number of point loads and obtain the same answer however this does not seem to be the case. I will post more on this later in a different thread currently I'm interested in the history.
Are there any texts that explain/discuss the text results and the modifications?
Thanks in advance!
I have been researching this topic the last week pretty extensively and will have some questions based on the actual calcs that I will post in a different thread.
I'm curious as to why the same equation is used with credit given to different people. I'm curious of each persons contribution.
Point Load modification: Terzaghi (most commen), Spangler and Midlin.
Line Load modifications: same as above.
Strip Load: Credit seems to be given to Tang. However it does not appear that this calculation is modified. The equation is given in Poulos and Davis and there is no comments that it is modified but some say it is modified by Tang. Are there any modifications to the strip load equation (except for the factor of 2 debate)? If it is not modified I should be able to discritize a strip load into a number of point loads and obtain the same answer however this does not seem to be the case. I will post more on this later in a different thread currently I'm interested in the history.
Are there any texts that explain/discuss the text results and the modifications?
Thanks in advance!
EIT





RE: Offset Surcharge - Bousinessq History of Modifications
RE: Offset Surcharge - Bousinessq History of Modifications
Some researchers say this is because there is a mirror image, others say the new wall can not take shear stress, yet some say measured experimental values are just 2 time the theory. You pick the explanation you like, just plug the 2.0 in the numerator!
For references, try Tschebottariof, R.F. Scott, Jumikis and Cernica.
RE: Offset Surcharge - Bousinessq History of Modifications
I thought that only the point and line load formulas where modified by Terzaghi and that the strip load was just an integration but no modification. Is that correct or is the strip load equation modified as well?
The equation I refer to is
Pstrip = k* Q/pi * (beta-sin(beta)*cos(2alpha))
where k=1 for very flexible wall. k=2 for rigid wall
I ask because when I compare it to my spreadsheet I get different solutions. Also what is the modification?
EIT
RE: Offset Surcharge - Bousinessq History of Modifications