SOE Design Requirements
SOE Design Requirements
(OP)
Are there any means to quantify the effects of vibration on an SOE system?
A contractor installed an SOE wall approximately 10ft deep less than 2ft from an existing masonry building on a spread footing. The SOE wall was made from drilling 8" pipes into the ground and sliding steel plates behind them while excavating. The adjacent building was relatively stable until they started driving piles 60-80 ft away. At that time, the foundation dropped at least 1" and moved away from the building 1/2" or so, all during two days of pile driving.
There is no question that the SOE failed and that the building foundation has failed. I am wondering if there could have been any way to figure on the effects of pile driving so close by. All visible excavated ground is sand.
I can't imagine that this system was in fact engineered. If it was, the engineer has also failed. Are there any code/OSHA/typical requirements to engineer SOE systems over a certain depth?
Miscmetals
A contractor installed an SOE wall approximately 10ft deep less than 2ft from an existing masonry building on a spread footing. The SOE wall was made from drilling 8" pipes into the ground and sliding steel plates behind them while excavating. The adjacent building was relatively stable until they started driving piles 60-80 ft away. At that time, the foundation dropped at least 1" and moved away from the building 1/2" or so, all during two days of pile driving.
There is no question that the SOE failed and that the building foundation has failed. I am wondering if there could have been any way to figure on the effects of pile driving so close by. All visible excavated ground is sand.
I can't imagine that this system was in fact engineered. If it was, the engineer has also failed. Are there any code/OSHA/typical requirements to engineer SOE systems over a certain depth?
Miscmetals





RE: SOE Design Requirements
Questions to consider:
1. How deep are the existing footings below the top of the 10' high SOE wall?
2. How high above subgrade is the botton of footing?
3. How far away from the SOE wall are the edges of the existing footings?
4. What is the footing load and what is the floor load inside the lowest floor level?
5. Were the pipe soldier beams set and concreted into larger diameter holes?
6. Was the SOE wall braced or tiedback? If so, at what elevation relative to the bottom of footings?
7. Was the building monitored from start of SOE wall construction? When did movement really start?
8. What are the soil and ground water conditions?
9. When the steel plate lagging was installed, was the dirt behind it tight against the plates? If not, then the dirt under the building had to fail before the earth and surcharge loads could be transferred to the soldier beams which then would also deflect laterally causing more settlement.
Sometimes, a poor design can be the problem. Sometimes, the SOE method is inappropriate. Sometimes, poor construction is the problem. Sometimes, the field conditions are not as expected. We don't have enough information to determine which factor or combination of factors caused the building to move. However, I'd bet that there are several contributing factors and guilty parties involved. Sorry.
RE: SOE Design Requirements
As PEinc will undoubtedly (and correctly) point out, those were quite stiff, strong walls - a far cry from the 8 inch pipe piles and steel sheeting described in the original post of this thread...
Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora. See FAQ158-922 for recommendations regarding the question, "How Do You Evaluate Fill Settlement Beneath Structures?"
RE: SOE Design Requirements
And I did find OSHA standard 1926.652 which governs the requirement for design of SOE systems.
thanks,
miscmetals