Cooper E-80 Live Load - flexible wall system

[RFreund]

Is there any reduction to the Boussinesq pressure distribution for flexible wall systems?

I know review rail engineers are pretty 'finicky' so I tempted to not even bother but these are small segmental walls which may end up with large grid lengths. But that may be the case. Attached is a section if interested.
It looks like the line of influence both walls once grid is installed. So I may just design for the full loading. Thoughts?

EIT

http://www.HowToEngineer.com

 

[dcarr82775]

There must be since Boussinesq distribution assumes a rigid condition. What that reduction may be is another issue. Given it is a railroad, I would just use the bigger number. Seems like MSE walls are not a great way to go.

 

[GeoPaveTraffic]

I doubt that MSE walls can be used. To install the grids will require excavation well into the influence zone of the E80 loading. Most railroads will require a very extensive, i.e very expensive, shoring system to install the grid.



Mike Lambert

 

[PEinc]

This has been discussed in this(?) forum. Arbed's ProSheet sheet pile design program seems to reduce the Bioussinesq pressures by a Ka fActor for flexible sheet pile walls. CivilTech's Shoring program allows the user to select rigid, semi-flexible, or flexible when using their Boussinesq surcharge program. The rigid setting gives the full pressure value from Boussinesq. The other two settings reduce that pressure. In my experience, railroads want the full rigid pressure.

http://www.PeirceEngineering.com

 

[RFreund]

Geo & PE - thanks for the info, I tend to agree w/ you. However the segmental unit supplier is the one coming to us for the advice. Thus I'm trying to see if there is something to work.

I have seen the Ka * vertical Boussinesq pressure before.

PEinc- any idea what CivilTech uses for semi-flexible or flexible reductions?

EIT

http://www.HowToEngineer.com

 

[RFreund]

Sorry found it.

Civiltech uses the Teng equation for strip load = Rigid - (2*q/pi*(b-sinb*cos2a))
Semi flexible = 0.75 * Rigid
Flexible = 0.5* Rigid

EIT

http://www.HowToEngineer.com