Alternative to underpinning

[Heldbaum]

Hello everyone,

I have a question regarding an underpinning. What is an alternative to the typical underpinning method ? An architect works on the project where they are adding an extra floor to the exist. residential building plus they want to deepen the exist. cellar of about 10 feet. There is no ground water expected at this level. There are adjacent buildings at both sides. The thing is that the neighbors do not want to agree on any underpinning. I am supposed to prepare the proposal for SOE design for this project. But before I do that, I'd like to find a solution. I was thinking about titan micropiles..But I have never done this before so I Am not sure how this works for cellar deepening with adjacent buildings around..? I know it works well for foundation remedies.. Does anyone have any solution/good didactic materials? I would appreciate every advice. Thanks!

 

[bookowski]

You cannot attach micropiles to the face of a rubble wall!! Whoever told you to do that was a kamikaze pilot in their past life.
Rubble walls are junk and unpredictable + you'd be introducing bending + that doesn't completely solve your soe - you'd still need to retain the soil under the neighbors. Don't do it.

You have two options: conventional underpinning or something like a secant wall. The secant wall or similar will be very expensive and they'll lose space. Pay the neighbors more for an agreement or forget it.

Don't mess with rubble walls - I've had a bad experience with them and don't suggest taking any risks. They're just piles of stone.

 

[oldestguy]

I'd listen to Hayward Baker and bite the bullet. Micro piles and the titan piles would only be used if you had a great deal of past experience with them in tough places.

 

[Heldbaum]

Thank you guys! I really appreciate your help!