Arching Action of MSE with Modular Block Facing

[jaggars]

I have a wall about 22ft high at the bottom of the wall there is precast box culvert opening about (3.6m wide X 1.5m high). The wall is holding up a roadway at the top. Some portion of the wall is sitting right above the precast box culvert opening. The wall will apply load on culvert.I am wondering can i consider arching action of MSE Facing & Reinforced soil to distribute a lesser load over culvert same concept which is applied for lintel/window opening on Building Walls.

Thanks for your suggestions.

 

[ishvaaag]

I wouldn't think it specially irregular; maybe I would consider 1H:2V good enough a load; however would proceed along any enforcing code to avoid later hassles. Also would look to the effect heavy wheels or axles might have, just in case.

 

[fattdad]

Spangler has equations for this, if I recall correctly. You may need to consult a reinforced concrete pipe manual, but there are charts for this problem (I think. . .).

f-d

¡papá gordo ain’t no madre flaca!

 

[Riggly]

Jaggars,
I am trying to visualize this. Is is an MSE wall, or are you trying to incorporate soil reinforcement to utilize arching? Dr. James Collins did extensive work with arching effect and load transfer platform. If you can get a hold on his paper, that would be very useful. The difference here is trying to 'bridge' over a stiff material versus a soft soil layer. Due to the stiffness of the box culvert, I would expect significant load will be induce on it (similar to structures, the stiffer member will carry most of the load). To utilize this arching more effectively you would have to place VCC or drill piers along the length of both sides of the culvert and place the MSE load transfer platform. You can also use lightweight fill above the culvert to reduce the overburden. I was involved in a project where we utilized both these concepts. I found one of Dr. Collins paper online- see below.

http://geosynthetica.net/tech_docs/NAGS_GRI19/CollinHanHuang.pdf

 

[GeoPaveTraffic]

I agreee with Riggly, if a portion of the wall is sitting on the culvert, then load will arch to the culvert. In the end the amount of load carried by the culvert will be significantly greater than the weight of wall directly resting on the culvert.

 

[jaggars]

Thanks Guys,

Yes this is a MSE wall part of a road widening project. MSE wall is on both sides of an approach road the wall is about 8.0m(24.0 ft)with flexible precast box culvert at bottom (4.0m X 1.5m) opening to allow for passage of creek water. I like the idea of using a light weight material at portion of wall above culvert. I am also considering to separate that 4.0m section by an expansion joint going all the way up to the roadway meaning keeping the 4.0m wall panel section as separate from rest of the wall. Also at the modular facing portion may be design a RCC Collar to take the load from blocks above.