Surcharge load examples

[jenofstructures]

Hello everyone,

I am looking for example for retaining wall design with one strip loading as surcharge. I have some books discussing the Lateral Pressure on Retaining wall due to strip loading but it did not give examples on it, but the formula itself.

Been scanning some internet infos regarding this but it showed 2 types of formulas, the with PI and the one without it. I dont know what is the right formula

Another is that i believe that the formula is derive from Boussinesq method, but i just want to have some examples on how did this formula derived from the said method.

I will appreciate any help
thank you very much



Poems are made by fools like me, but only God can make a tree. engineers creates wonderful buildings, but only God can creates wonderful minds

 

[ishvaaag]

Ingeniería de Cimentaciones
Peck, Hanson, Thornburn
Limusa
México 1994

This page of the book relates the given charts for Boussinesq-like pressures on the backplane of the wall due to point or line loads to experiments of Gerber (1929) and Spangler (1938).

 

[ishvaaag]

CTE is the current code that covers construction of buildings footings to roofs in Spain. It has, between other things, provisions for simplified wall loading due to strip loads. Use the c=0 variant for cohesionless soils and c unequal to 0 for coherent soils.

 

[ishvaaag]

The Bowles' text has some history about the derivation of the Boussinesq's-like loadings on the backwalls for strip loads.

Look also the first page at top right. You see there the common assumption of the affected zone by some point load. This same figure can be also seen at the

La ingeniería de Suelos en las Vías Terrestres, Carreteras, Ferrocarriles y Aeropistas, Volumen 1
Rico, Del Castillo
Limusa
México 1994
page 270

in the same context of helping to determine the position of the resultant of the active pressure in the backplane of the wall. So the simplified zone of pressure would coincide with the one for the noncoherent backfill of CTE (see post above). All this related to Culmann-like determination of the active pressure. The assumptions of the zone of the wall seem so quite accepted for the case.

I have not found yet a quite precise derivation of the simplified loadings, but may have in some of the geotechnical books that I have in the cabinet I access but few times a year. If find something, will say.

 

[ishvaaag]

This Mathcad 2000 Worksheet gives the horizontal stresses created in a given vertical plane by a parallel strip load at the surface. If the wall would substitute with equal effect the suppressed soil of the excavation and the soil was an elastic halfspace, these would be the stresses in the backplane.

Note that the loading in the strip loads needs not be merely vertical, can also have an horizontal component (say, friction against skid action).

 

[ishvaaag]

Also found a related thread

http://www.eng-tips.com/viewthread.cfm?qid=102196&page=24

 

[jenofstructures]

thank you for all of our help!!!!!

Poems are made by fools like me, but only God can make a tree. engineers creates wonderful buildings, but only God can creates wonderful minds