Uncategorized
A city in Alabama discovered severely deteriorated sewer lines, which could fail at any moment, during routine maintenance on a 36-inch trunk sewer line. The city engineer and sewer department determined that the 36-inch trunk line had several upstream and downstream segments with severe weakening due to age. A quick point repair would not alleviate the issue. A permanent repair needed to be completed on several hundred feet of the trunk line quickly and safely. 
During the sewer main repair, the streets had to remain open and the sewer had to continue flowing so residents would be unaffected and could continue to use their services. The ideal solution for the repair included installing a single cured in place liner for the most deteriorated section of the pipe, requiring the sewer to be bypassed around the section being rehabbed.
The solution to rehabilitate the pipe included relining 750-feet of trunk sewer with a cured in place liner which ran the complete length of the pipe. The main bypass required 2.7 million gallons a day (MGD) for peak dry flows and 11 MGD for peak wet weather conditions. A second bypass was necessary for a 12-inch force main that entered the trunk line in the section that was to be rehabbed. It handled flows of 0.5 MGD for normal conditions and 3.5 MGD for wet conditions. The 1,200-foot bypass included six intersection crossings during the quick one week project.
The contractor chose Rain for Rent because of a long, successful history working together on dozens of pumping projects over the past several years. Relying on prior bypass pumping expertise and by utilizing GPS technology , the contractor, city and Rain for Rent were able to minimize road closures by identifying the order and timeframe to close each street during the initial job walk.
Rain for Rent’s certified fusion technicians fused the HDPE pipe on the project, ensuring a leak-free system. Prior to starting the bypass operation, Rain for Rent confirmed the pipeline’s integrity by hydrostatically testing the entire system.
To alleviate the need to excavate the suction manhole, a single 18-inch HDPE suction stinger was manifolded to four 6-inch DV150i sound attenuated pumps. These pumps were then manifolded through gate valves into a single 18-inch HDPE discharge pipe that ran the length of the project.
At each intersection, an 18-inch steel road crossing was placed to allow for traffic to continue without disturbance. Each road crossing was smoothed out with cold patch asphalt to minimize the bump for traffic flow. Sound attenuated pumps ran 24/7 during the installation of the liners, keeping the operation quiet.
To give the 12-inch force main bypass enough head pressure to break into the existing flow of the 18-inch sewer line bypass, the project utilized a pump drawing water from a 21,000 gallon reservoir tank to pressurize the system. Because the tank is portable and only 8-ft wide, cross street traffic continued to flow. The contractor installed a temporary connection at the force main and flanged high pressure hose was used to plumb the force main into the tank. An additional six-inch DV150i sound attenuated pump was used to move the liquid from the tank through a gate valve into the 18-inch HDPE bypass line.
The CIPP contractor installed a direct inversion liner to repair the aging sewer lines. This solution was the fastest, least obtrusive solution to rehabilitate the lines, quickly getting the pipelines back into service.
The city averted an emergency situation by taking action when the initial damage was discovered, collaborating with the CIPP contractor and Rain for Rent, completing the project within the one week timeframe. The 200,000 residents of the city were unaffected by the bypass. With a total of approximately 15 million gallons pumped, the bypass was completed safely without incident during the nearly 210 man hours worked during set up and tear down on the project with an additional 96 hours for 24 hour-a-day pump watch.
Written by Brian Brandstetter. Photo courtesy of Rain for Rent.
Uncategorized
In November, 2013 Armin W. Stuedlein, PhD, PE and Tadesse Meskele of the Geotechnical Engineering Group, School of Civil and Construction Engineering at Oregon State University completed a research project on pipe ramming installations for the Oregon Department of Transportation and the Federal Highway Administration.
Background: Culverts are an essential component of roadway drainage systems that transport storm runoff and stream channels from one side of a road to the other. The majority of culverts installed in the 1950s and 1960s are reaching the end of their functional lives and need replacement due to structural deterioration, scour, corrosion, erosion, separation, or increased hydraulic requirements.
The traditional open cut method is the most widely used method for installation or rehabilitation of underground pipelines, conduits, and culverts. However, the open-cut method requires time-consuming excavation, installation and back-filling, which can impose an adverse impact on the daily life of society by creating road or rail closures, traffic delays, detours, loss of access to homes and businesses, and undesirable noises (Ariaratnam et al. 2006). Thus, engineers and contractors are gradually abandoning open trench cutting and embracing trenchless methods of pipe installation. These trenchless methods can mitigate many of the logistical issues associated with traditional approaches. In particular, pipe ramming, which is a simple non-steerable trenchless construction technique, is becoming an emerging method of pipe installation, because it allows installation of casings in soils with large cobbles and boulders, which are ground conditions that may pose greater difficulty to other trenchless techniques. Pipe ramming is also a commonly chosen technique for shallow pipe or culvert installation under roads and railways, where other trenchless methods could cause unacceptable ground settlement or heave.
Need for this Research: Despite the growing popularity and experience with pipe ramming, there is surprisingly little technical guidance available for engineers to plan pipe ramming installations appropriately. Stuedlein and Meskele presented a preliminary, baseline engineering framework for the design of pipe ramming installations.
Objectives of the Study: The main objective of this research is to study the mechanics of pipe ramming and to develop a rational engineering framework for the optimal design and specification of pipe ramming installations.
To learn more about this research and to read the full report click here.
Thank you to School of Civil and Construction Engineering, Oregon State University for providing this content and photo. Photo info: Pipe ramming performed at an experimental test site for the OSU research project. This test ram was made possible in part by members of the NUCA of Southwest Washington and Oregon.
Uncategorized
Aegion Corporation announced that its subsidiary, Insituform Technologies, LLC has been awarded two contracts with a combined value of $7.4 million from Metro Water Services in Nashville, Tennessee.
Beginning in early 2014, Insituform crews will install Insituform® cured-in-place pipe (CIPP) in over 13 miles of 8- to 18-inch wastewater pipelines, primarily in residential areas throughout Nashville. Insituform will oversee local subcontractors and small businesses that will perform manhole rehabilitation, concrete and paving work, site preparation and restoration and lateral lining.
Jeff Kowal, Vice President and General Manager of Insituform’s East Region, said, “Metro Water Services is implementing its 11-year Clean Water Nashville Overflow Abatement Program to improve its wastewater system infrastructure. These improvements will provide lasting benefits for future generations and provide a clean, healthier environment for the citizens of the greater Nashville area. This is a significant undertaking and we are proud to work with MWS on its efforts to ensure local residents realize the full benefit of these rehabilitation projects. We will continue to pursue additional projects that are planned by MWS in an effort to support its program.”
The projects are expected to be completed in 2014.
Thank you to Aegion and Insituform for providing this content and photo.
Uncategorized
Cobb County-Marietta Water Authority (CCMWA) is the second largest drinking water supplier in Georgia, providing vital service to nearly 800,000 people through twelve wholesale customers. With two award-winning water treatment plants and over 200 miles of large-diameter transmission mains, CCMWA can deliver up to 158 million gallons per day. Two of CCMWA’s key objectives are to be financially viable and to reduce vulnerabilities by improving redundancy and implementing a comprehensive asset management program.
However, across the United States critical infrastructure is aging, causing utilities to see an increased number of water pipe failures. While these failures occur most commonly on small pipes – causing only minor disruptions – large-diameter mains do fail, resulting in major delays and enormous repair bills.
A large portion of CCMWA’s large-diameter pipeline inventory is made up of Prestressed Concrete Cylinder Pipe (PCCP). In order to successfully manage PCCP, the water industry has widely adopted the use of condition assessment techniques, which have a proven track record of identifying and averting PCCP failures. PCCP owners and operators continue to use these condition assessment methodologies combined with sound engineering analysis to effectively and safely manage their critical assets.
Cobb County’s Program
In 2012, CCMWA was in a similar situation to many predominant PCCP users; past failures on these critical assets had led to the decision to replace the majority of PCCP assets to avoid the risk of future failures. However, it was determined that replacing large sections of pipeline was not financially or logistically feasible.
Large-scale replacement programs are also unnecessary based on industry research, which confirms that pipe deterioration is not uniform or systematic. Specifically, electromagnetic inspection data (which identifies both the quantity and location of broken prestressing wires – the primary structural component of PCCP) collected by Pure Technologies over more than a decade indicates that less than 4 percent of pipe sections inspected have any level of wire break damage and less than 1 percent require repair – regardless of when it was manufactured.
photo caption:
Staff remove the PipeDiver tool after the non-destructive assessment.
Uncategorized
In mid-October 2013
, construction was finalized on the installation of 2,944 ft. (897m) of new 36-in. (914mm) ID storm and sanitary pipelines using pilot tube guided boring methods in Mexico City. The Subcolector San Marcos project, owned by La Comisión del Agua del Estado de México (CAEM), represents the first trenchless installation with this technique in Mexico. The Subcolector San Marcos project embodies the successful and accurate completion of the alignments, but more importantly, the culmination of several years of partnerships to educate, design, and procure equipment and pipe among many entities. Crews installed the total 2,944-ft. (897m) in eight drives, ranging from 186 to 441-ft. (57-134m) in length, from nine minimal depth and diameter shafts in the urban Plaza de Aragon, Ciudad Nezahualcóyotl municipality of Mexico City. More information about this project can be gleaned during our presentation, WM-T4-05, at NASTT’s 2014 No-Dig Show.
Thank you to Akkerman for providing this content and photo.
Uncategorized
The TOHO Water Authority (TOHO) has been acquiring and integrating water utility systems in Osceola County near Orlando, FL. As part of that growth, a 24-inch interconnect in Kissimmee, FL was required to provide adequate redundancy in the system. The route of the 24” water main required a key crossing at the Florida Turnpike. After evaluation of alternatives, the design team including CPH, Inc. and TOHO concluded on a single horizontal directional drill (HDD) installation as the most practical solution to cross the highway. The FDOT Turnpike office required encasement for the pipeline within their right-of-way, including minimum depth requirements, which in turn drove the required size of the casing, bore hole, and ultimately the depth required for the crossing.
“24” DR18 Fusible C-905® carrier pipe and 30” DR21 Fusible PVC™ casing offered the only practical pipe material option for this specific application”, commented project engineer, Jay Morris, P.E.. Jay added, “The high hydrostatic design basis (HDB) of Fusible PVC™ enabled us to minimize the OD of the casing pipe and the corresponding depth of the bore alignment, in accordance with FDOT guidelines”.
| Pipeline Details and Project Summary |
| Project: |
Osceola Parkway – Florida Turnpike WM Crossing |
|
Location:
|
Kissimmee, FL |
| Length: |
1,500’ |
| Pipe Size: |
30” DR21 FPVC® Casing, 24” DR18 Fusible C-905® Carrier |
| Pressure Test: |
Casing – 65 psi; Carrier – 150 psi |
| Installation: |
Casing Pipe – HDD, Carrier Pipe – Slipline |
| Owner: |
TOHO Water Authority |
| Engineer: |
CPH Inc. – Jay Morris, P.E. |
| Contractor:
HDD Contractor: |
Andrew Sitework, LLC – Ralph Andrew
Accurate Drilling Systems(ADS) – Lauro Acevedo |
| UGSI Contact: |
Robert Tatum (941) 320-2440
rtatum@undergroundsolutions.com |
Ralph Andrews, the GC on the project said, “the technical, fusion and construction support from Underground Solutions, Inc. (UGSI) contributed to smooth and straight forward project execution”. “We had a tight construction schedule and we completed the project on schedule, he added.
Thank you to Underground Solutions, Inc. for providing this content and photo.
