Valve Vault Infiltration Grouting
The Job
As part of the Purple Line project in Maryland, a large diameter water line was relocated. The tie-in was done inside a 10′ diameter vault that was about 20′ deep, and done in a liner plate shaft. The vault structure was precast.
The Challenge
The vault structure wasn’t concentric in the shaft. This left little room to pour the closure around the pipe penetrations. One of the penetrations leaked, causing the structure to completely fill with water. Per specifications, it needed to be dry.
The Solution
CJGeo proposed grouting the infiltration points with CJGrout-35NHV61. 35NHV61 is a hydroinsensitive, plural component geotechnical polyurethane, certified for potable water contact.
CJGeo mobilized a three person crew to the site, and was able to stop the various leaks in the structure in a few hours.
Illinois Spillway Grouting
The Job
A spillway serving as a dam for a lake owned & maintained by a property owner association outside of Carbondale, Illinois stopped having water flowing over the spillway. The property owners determined that the lake was draining through voids under the spillway slab. This made them concerned about destabilization of the spillway, which was the sole access for six homes.
The Challenge
The flow velocity was rather high, and immediately on the other side of the spillway was a 30′ cliff, that the water was designed to spill over as a waterfall. Given the extraordinary difficulty of retrieving any material washed over the waterfall, the grout had to have an exceptionally fast set. It also needed to provide adequate bearing capacity for the roadway slabs.
The Solution
CJGeo proposed grouting below the spillway with CJGrout 40NHL, which is usually used for differential settlement correction. CJGrout 40NHL performs well for differential settlement correction because it reacts very quickly, and is used for medium duty lifting, such as highway pavement, so it would provide more than enough bearing capacity.
The owners were very excited that it would be significantly less expensive to grout the existing spillway than to have someone local install a portadam and replace the entire structure. CJGeo mobilized a single polyurethane grouting crew to the site, and they stopped the leaks and kicked all the water flow over the spillway in a single day.
Willow Springs Crossings
The Job
BNSF’s Willow Springs Intermodal yard is a critical facility in United States’ freight rail network. The facility is colocated with a large UPS trucking operation, and BNSF has very tight time lines for transferring containers from inbound trains to UPS.
The Challenge
80 StarTrack modular grade crossing panels across 10 different crossings in the facility experienced settlement. The settlement was affecting the safe operation of yard trucks, causing delays in container transfer times.
Because of the 24/7/365 operation, and very tight performance times, there was no tolerance for downtime.
The Solution
CJGeo proposed grouting the affected panels with CJGrout-48NHL. 48NHL is specially formulated for differential settlement correction in high load applications, such as heavy haul rail.
CJGeo mobilized a polyurethane grouting crew with extensive modular grade crossing repair experience and grouted the 10 crossings over a period of five days onsite. The grouting was done without affecting rail traffic, yard truck operations, or performance metrics.
8′ CMP Joint Grouting
The Job
A spec warehouse was planned for a vacant piece of land which had 1700LF of 8′ CMP running through it. The pipe was installed when the site was first prepped, approximately 10 years prior to construction. Because the site was vacant, there was no maintenance. Nearly every joint showed signs of soil infiltration, and there were massive sinkholes along the entire alignment.
The Challenge
To avoid having the replace the entire run of pipe, the joints needed to be sealed. There were 80 pipe joints and 12 pipe to structure joints that were affected.
The Solution
CJGeo mobilized a polyurethane grouting crew to the the site. Over the course of a week onsite, the crew sealed all of the joints. As part of the joint sealing, the voids around the pipe were filled with CJGrout 20SDB geotechnical polyurethane. After the grouting work was done, the site contractor backfilled the sinkholes and washouts with soil.
Medical Clinic 3′ Void Fill
The Job
The medical clinic on a military base was being renovated. As part of the renovation, the 650sqft elevated slab front porch needed to be replaced. The slab “sounded hollow,” and the presumption was that there were nominal voids below the slab.
The Challenge
At the start of demolition, the demolition contractor determined that the voids below the slab were closer to 3′ deep. This presented a safety problem for the demolition. The concern was that the slab would fail catastrophically during demolition. The general contractor reached out to CJGeo about ways to reduce the void depth.
The Solution
CJGeo proposed void filling below the slab using CJGrout 20SDB. CJGrout 20SDB is a low exotherm bulk void filling geotechnical polyurethane specifically formulated for deep fill placements without scorching or charring. A two person crew mobilized to the site and placed approximately 2,900lbs of CJGrout 20SDB in a few hours onsite, allowing the demolition contractor to safely resume work.
New Jersey Grade Crossing Stabilization
The Job
A precast modular grade crossing (Oldcastle StarTrack) crossing developed significant pavement deterioration. NJDOT directed the railroad to stabilize and lift the panels and then patch the adjacent asphalt.
The Challenge
The grade crossing sees up to 8 trains per day (heavy industrial service), and crosses a four lane arterial highway. So, there wasn’t any allowable downtime.
The Solution
CJGeo proposed grouting the panels using CJGrout 60NHL. 60NHL is a geotechnical polyurethane grout specifically formulated for heavy applications such as rail and aircraft loads. A CJGeo polyurethane grouting crew mobilized to the site and in fewer than 2 hours onsite restored the affected panels.
Warehouse Floor Joint Stabilization
The Job
About two months after occupying a new warehouse in Ashland, Virginia, the tenant identified two joints where the floor “popped” at a joint when a forklift drove over them. After consulting the plans, the owner determined that the joint wasn’t doweled.
The Challenge
Both affected joints were on main, high frequency travel pathways within the warehouse. So, any repairs had to be done quickly, and with zero impact to operations.
The Solution
CJGeo proposed undersealing the two joints, which had experienced slab curl, with high density geotechnical polyurethane grout. In fewer than three hours onsite, CJGeo undersealed the joints with CJGrout 20SDB, load tested them, and demobilized. There were no impacts to operations of the facility.
CBBT Pregrouting
The Job
The Chesapeake Bay Bridge Tunnel’s Parallel Thimble Shoal Tunnel Project is constructing a second tunnel parallel to the original to reduce traffic congestion. All work is being performed from man-made islands in the Chesapeake Bay which are densely packed with utilities, equipment and operations facilities associated with the existing tunnel, which is in continuous use.
The Challenge
During previous phases, installation of sheet piling for tunneling activities and other driven elements induced consolidation of the loose sandy fill on the islands, causing settlement of duct banks, pavements and other structures, which were remedied by CJGeo using polyurethane compaction grouting.
In this case, sheet piles had to be driven immediately adjacent to the roadway in order to excavate the receiving pit for the tunnel boring machine. The construction team was concerned about inducing settlement of the adjacent roadway, so reached out to CJGeo about performing compaction grouting under the footing for the original tunnel’s portal wall, after the wall had been demolished down to grade.
The Solution
CJGeo performed compaction grouting utilizing an NSF-certified potable water contact plural component polyurethane grout. Cutoff criteria was 0.10 inches of movement of the foundation or adjacent roadway. Upon completion of the compaction grouting by CJGeo, sheet piling installation started, with only nominal movement of the foundation and roadway.
North Carolina Tub Crossing Repairs
The Job
Fifty two OldCastle StarTrack panels at four different grade crossings settled to the point of requiring slow orders at the crossings. In order to restore the track to normal speeds, the settlement needed to be corrected.
The Challenge
Due to scheduling constraints with rail traffic, with very short windows on weekend nights, the owner elected to have the repairs completed during a single weekend shutdown period. While this allowed for longer work periods, it also meant that four crossings needed to be repaired in fewer than 24 hours.
The Solution
CJGeo mobilized two polyurethane grouting crews to the system, and grouted two crossings each during two shifts. All 52 of the panels were stabilized and lifted back to grade using CJGrout 60NHL, which allows for immediate resumption of rail traffic, from light rail to heavy haul.
Spillway Bridge Grouting
The Job
Two DOT-maintained bridges crossing two privately owned dam spillways had to be closed because of extensive undermining of the spillways. The undermining was allowing nearly all of the flow to happen below the spillway slabs, which caused large sinkholes to form adjacent to and under the roadway pavement, and also led to some settlement of the spillway slabs.
The Challenge
There was very little room to work–just under 4′ of clearance below the bridge beams. Also, the velocity of the water through the voids below the structure was quite high.
The Solution
CJGeo proposed a combination of plural component polyurethane grouting to address the water flows and voids, and hydrophobic chemical grout placed directly into cracks. A single CJGeo grouting crew was able to complete the repairs in a day (roughly 2500sqft of work, and approximately 4500lbs of polyurethane, plus 30 gallons of hydrophobic chemical grout). Dye testing during and after the grouting work confirmed that no more leaks were present under or around the spillway structures.
