Dumfries Pipe Abandonment
The Job
This utility relocation included abandonment grouting as part of a VDOT roadway reconstruction and realignment in Dumfries, Virginia.
The Challenge
1,575LF of pipe, a combination of 54″ & 60″ needed to be completely filled with grout. Due to sequencing, the pipe was underneath new roadway at the time of abandonment, so the fewer the number of access points, the better.
The Solution
CJGeo placed 995CY of CJFill-UL14 to completely fill the pipe run. The material was placed in a single day, from a single access point near the center of the pipe run.
Savannah Tunnel Abandonment
The Job
The JW Marriott Plant Riverside is an adaptive reuse hotel project of a decommissioned power plant in Savannah, Georgia. As a thermal generation facility, there are extensive water tunnels below the structure. The tunnels were cast in place during original construction, and integrated into the pile supported foundation.
The Challenge
As part of the conversion from thermal power generation to luxury hotel, the tunnels needed to be filled. Due to concerns about inducing settlement with traditional flowable fill, the designer specified EPS Geofoam blocks. These would have effectively eliminated loads, but were deemed impossible to install.
The Solution
Someone onsite had heard of cellular concrete, so reached out to CJGeo. CJGeo evaluated the layout of the tunnels, isolation methods from the river, and designed a mix which would ensure both complete filling of the structures without adding any additional load.
CJGeo placed approximately 930CY of 20lb/cuft CJFill-UL cellular concrete over a period of three days. Because CJFill-UL is highly mobile, demo debris from the access holes for building bulkheads was left in the tunnels and encapsulated with the CJFill-UL.
66″ Water Main Abandonment
The Job
The Purple Line is a light rail line project in suburban Maryland designed to increase connectivity within Maryland’s suburbs of Washington, DC. The project involves extensive utility relocation to facilitate installation of large embankments and the extensive infrastructure required for a double track rail corridor dropped into the middle of an already exceptionally congested/dense corridor.
The Challenge
As part of the project, a large MSE wall needed to be installed over approximately 3000LF of 66″ PCCP water main. In order to avoid any future maintenance problems under the rail alignment, a new line was installed adjacent to the embankment, and the old line needed to be abandoned.
Due to construction sequencing, the embankment was already in place well before the water line relocation was performed.
The Solution
CJGeo worked with the utility relocation contractor to design a grout mix and grouting program that provided sufficient bearing capacity to eliminate concerns about future stability. The ultimate design for the mix was a 100psi cellular grout. Given that the embankment was already in place, the entire 3000LF stretch had to be grouted from just two access points.
CJGeo used a 200CY/hour dry mix batch plant onsite to generate and pump the cellular concrete up to 1500LF to place the material. 2800CY of material were placed over a period of four days onsite with no disruptions to adjacent construction activities.
Garden State Parkway grouting
The Job
As part of ongoing large diameter culvert rehabilitations and replacements, four new bored stormwater crossings and the original culvert they replaced needed to be grouted. The tunnels ranged from 120″ down to 74″, for a total of 312CY, and the abandonment required 405CY.
The Challenge
Grout needed to meet the minimum strength requirements of the owner, and ideally needed to be light enough to facilitate single lift annular space grouting.
The Solution
CJGeo’s preconstruction team worked with the general contractor to design a grouting program which facilitated single lift abandonment of the original culvert, and single lift grouting of the four various annular space runs. CJGeo utilized onsite dry batching to generate 30lb/cuft CJFill cellular concrete.
8″ Pipe Abandonment
The Job
As part of continuing waterline replacements, a utility contractor in Fort Washington, Maryland, needed to abandon 10,600LF of 8″ water main. The utility and DOT both require grouting of all utilities 6″ and larger taken out of service.
The Challenge
In order to minimize the number of placement points, the grout needed to be exceptionally mobile.
The Solution
CJGeo proposed a 30lb/cuft cellular grout, and worked with the client to design a grouting plan that would allow grouting all 10,600LF of pipe from just three access points. CJGeo performed the grouting over a period of two days, with no additional excavation required from the customer other than their original tie ins/disconnects.
24″ Water Main Abandonment
The Job
As part of a large transportation project, 2000 linear feet of 24″ water main needed to be relocated out of a highway right-of-way.
The Challenge
Due to phasing, the old water main was located under the existing roadway and could not be accessed, except for at one point near the center of the run. So, the abandonment grout had to meet VDOT’s minimum strength requirements for flowable fill, and be pumpable up to 1100LF at low pressure.
The Solution
CJGeo grouted each run of pipe using 30lb/cuft cellular concrete. Each placement took fewer than two hours, and required no additional traffic control, disruptions to other construction activities, or help from the utility contractor after they installed the bulkheads.
Rising Mains 48″ Abandonments
The Job
As part of the Rising Mains No 3 & 4 replacement project, roughly 1575LF of 48″ water main needed to be grouted.
The Challenge
The abandonment was specified for flowable fill, however the contractor had doubts about being able to successfully perform the abandonments with flowable fill due to access limitations, ready mix delivery limitations and the roughly 20′ of elevation change over the length of the pipe.
The Solution
CJGeo proposed 25lb/cuft cellular concrete, with an average of 80psi compressive strength for abandoning the pipes.
Using onsite dry batching, CJGeo generated and placed 730CY of grout to successfully fill the pipe, which was access near the middle to create two segments. The work was completed over two days.
Power Station Pipe Abandonment
The Job
Dominion’s Bremo Bluff Power Station was taken off line in 2019. As part of complete decommissioning, demolition was performed in 2022.
The Challenge
Four, 48″ cooling water pipes needed to be filled with grout to ensure longterm stability of the surrounding area. In addition to the pipes, a junction box they all connected to needed to be filled.
The Solution
CJGeo generated and placed approximately 300CY of 50psi cellular concrete to fill the junction box and pipes. The material was generated onsite over the course of a few hours using dry batch generation.
1400LF 36″ Dead Headed LLO Abandonment
The Job
The Round Valley Reservoir, in Clinton Township, New Jersey is a 2300 acre man-made drinking water reservoir serving extensive portions of New Jersey. It was constructed by damming up two openings in a naturally-curved mountain.
As part of a dam upgrade project, a 1400LF, 36″ inner diameter LLO pipe needed to be grouted to place it out of service.
The Challenge
The pipe had been previously blind flanged, 180′ below the lake surface. There was a single, 12″ riser pedestal. There were numerous significant challenges to face, including:
- 2GPM residual leak from the blind flange buried in 15′ of lake floor debris
- inability to push sacrificial pipes more than 500′ up the pipe
- remote site with limited ready mix service
The Solution
CJGeo worked with the general contractor, diving subcontractor, sacrificial grout pipe installation subcontractor, geotechnical and civil EORs, and the owner, to develop a single stage grouting plan to place approximately 350CY of 68lb/cuft cellular grout from the downstream end.
Venting was achieved by installing a 4″ removable vent pipe from the pedestal riser, 180VF to the lake surface, terminating on a barge. Since there was only one opportunity to do the job correctly, CJGeo had two fully staffed grout plants onsite, and had all cement and mix water staged in onsite storage prior to the start of grouting to avoid any material logistics disruptions affecting the work.
CJGeo placed the 68lb/cuft grout over a period of a few hours, leaving an intentional air pocket at the high end to capture infiltrating lake water long enough for the grout to set prior to seeing lake head.
HRSD 24″ Forcemain Abandonment
The Job
HRSD’s Virginia Beach Boulevard Forcemain Replacement project installed more than a mile of new pipe to replace an aging 24″ force main.
As part of decommissioning the original force main, it needed to be filled completely with grout.
The Challenge
Due to extensive widening of the roadway, the pipe was originally constructed alongside, extensive commercial and residential development, the number of access points needed to be as few as possible. This was driven by extensive structures over/adjacent to the old pipe, and a desire to reduce disruptions to adjacent stakeholders, and the risk of any utility strikes during access pit excavation.
The Solution
CJGeo grouted more than 7,000LF of the 24″ pipe over a period of four working days onsite. The pipe was completely filled, which was verified by uniform material venting from the far end of each run. Run lengths ranged from 450LF to more than 2000LF.
