Slurry backfill behind Soldier Pile Lagging
Slurry backfill behind Soldier Pile Lagging
(OP)
My drilling contractor wants to backfill the cavity behind 4"x12" timber lagging with lean concrete ("slurry"). He says this is common practice.
I am worried that this material will not be permeable enough and excess hydrostatic pressure could develop. Still, waterproofing is required for the concrete face of wall, so maybe lean concrete would "weep" enough(?)
Does 2-sack lean sand/cement concrete (slurry) have adequate transmissivity for this purpose? Also, is low-slump slurry acceptable as backfill over a 4" diameter slotted PVC/gravel/geotextile subdrain?
I am worried that this material will not be permeable enough and excess hydrostatic pressure could develop. Still, waterproofing is required for the concrete face of wall, so maybe lean concrete would "weep" enough(?)
Does 2-sack lean sand/cement concrete (slurry) have adequate transmissivity for this purpose? Also, is low-slump slurry acceptable as backfill over a 4" diameter slotted PVC/gravel/geotextile subdrain?





RE: Slurry backfill behind Soldier Pile Lagging
www.PeirceEngineering.com
RE: Slurry backfill behind Soldier Pile Lagging
Thanx, PEinc
RE: Slurry backfill behind Soldier Pile Lagging
www.PeirceEngineering.com
RE: Slurry backfill behind Soldier Pile Lagging
Thanx for your reply
Lagging is already in place. A small slough concavity occurred before lagging could be installed; there is no void space below or behind the lowest lagging but there is a 6"-12" wide ~5' high void behind the upper lagging. It's too narrow to mechanically compact, so I've considered "self-compacting" pea gravel. We could also lower a geotextile across the bottom of the void area to help keep the pea gravel in place.
I've also thought about jetting the native DG into place behind the lagging. The jetted water would seep out between the gaps in the lagging.
RE: Slurry backfill behind Soldier Pile Lagging
www.PeirceEngineering.com
RE: Slurry backfill behind Soldier Pile Lagging
www.PeirceEngineering.com