Jack And Bore Annular Space Grouting

haymarket-annulus-slideChallenge:

A utility contractor installed nine new stormwater pipes under an interstate using jack & bored casings.  The carrier pipes were a mix of spiral metal, precast concrete, and corrugated HDPE.  The bores ranged in length from 150 to 350 feet.  Cellular concrete was required for the jack and bore annular space grouting due to run length and tight fit.

Limits:

All work had to be done from one side of the interstate highway (three lanes in each direction, plus full width shoulders and a median strip), as there was no access on the far side.  

jack and bore annular space grouting using cellular concreteThe Solution:

CJGeo proposed cellular concrete for the annular space grouting.  Cellular concrete is the preferred material for annular space grouting because it is highly flowable, and reduces the chances of damage to carrier pipes in long placements.  Cellular concrete was the best solution logistically for this project because it requires just 1/5th the number of concrete delivery compared to flowable fill.  This reduces traffic and eases scheduling, particularly in areas where securing concrete deliveries is difficult.

Result:

CJGeo successfully performed the jack and bore annular space grouting over three different mobilizations.  CJGeo placed 350 cubic yards of cellular concrete over the life of the project.  The mix design for this project was 30 pound/cubic foot neat mix cellular concrete.  30 lb/cuft was chosen to improve site logistics, by reducing the number of deliveries required.