Shear walls supported by micropiles

[killswitchengage]

Hi guys I hope you're doing great

We have a special situation in which an old building needs added shear walls to improve its stiffness against earthquakes. The shear walls are to be founded on micropiles.the soil is composed of about 13 m old fill made of sand gravel rocks debris underlined by a weathered schiste
Do you find such a solution to be viable? And what are the things that we should bare in mind and verify before validating this solution? Especially seismic behavior of the micropiles and the there connection to the shear wall foundation

 

[le99]

Due to its relatively small size, I doubt the effectiveness of the micro piles if placed too far apart. Can you provide the floor plan and mark the proposed shear wall location?

 

[MTNClimber]

Micropiles that are permanently cased down to bedrock and then socketed into the bedrock can develop high axial resistance with the benefit of the casing providing lateral resistance. It sounds like a viable option to me. You should consider having a local geotechnical contractor to see if they have any limitations since it sounds like they will be installing the piles inside of the existing building.

 

[killswitchengage]

Tbh my new boss wanted my advice on the subject but I am yet to start working for him as of now ( my entry starts the 4th of September)

That being said I don't have the full details other than it's an existing hotel with limited clearance space to work upon. I belive there should be no down drag issue provided the fill is not compressible. Also the hotel is founded on piles.
Le99 what do you mean? Effectiveness in terms of what?

Mtnclimber thank you

 

[le99]

I was questioning the effectiveness of resisting lateral load. I recommend consulting with whoever has had such an experience.