- ENGINEERING INFO
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The City of Del Mar, California is a well-known enclave within San Diego County, boasting beautiful coastline, estuaries, Torrey pines, and the famous Del Mar Fairgrounds owned by the State of California. With only 4,000 residents, the cost of maintaining and replacing aging infrastructure is challenging. A recent concern was the reliability of a 20-inch steel water main feeding the city from the north end of town. Replacing the pipeline using open-cut, dig and replace construction would have been expensive and highly disruptive with the existing pipeline located directly under busy Jimmy Durante Boulevard. The two-lane thoroughfare is a heavily travelled road and serves as the primary artery between the fairgrounds and Del Mar’s downtown area.
As part of a larger streetscape upgrade, the City engaged Nasland Engineering to consider options for replacing or rehabilitating the 20-inch water line. Nasland previously completed several projects with Fusible PVC® pipe throughout San Diego County and recognized it as a potential solution to resolve project challenges, including cost, traffic congestion, and the requirement to complete the project before the busy summer season.
Contract Bid Structure
In order to ensure a cost-effective solution, the City bid the project with two alternate construction methods: Open-cut replacement with 12-inch bell-and-spigot PVC pipe or sliplining the existing steel pipeline with 12-inch Fusible PVC® pipe. The successful bid submitted by PAL General Engineering was based on sliplining, which produced an overall project savings exceeding $70,000 compared with the open-cut option.
With contract in hand, PAL General Engineering hired TL Scanlan as a subcontractor to perform the sliplining scope of the project. TL Scanlan excavated pits at both ends of the 2,015 LF slipline section. Additional open-cut excavations were performed at two alignment offsets, which enabled a single pull-in through the entire length of the alignment. Limiting excavation to four pits greatly reduced the amount of traffic control and diversion required during construction.
Following excavation of the pits, 45-foot lengths of Fusible PVC® pipe were fused and pulled into the existing host pipe. This “fuse-and-pull” approach allowed the entire 2,015 LF section of host pipe to be sliplined in just four days without having to stage long sections of fused pipe above ground.
Mohammad Qahoush of PAL General Engineering stated, “Underground Solutions had experienced staff on site before and during the install; working with the project owner, inspection team and PAL to generate the most cost-effective, time-saving, and commuter-friendly construction plan.”
Tom Scanlan with TL Scanlan commented: “I was initially reluctant when the City selected the option to slipline with Fusible PVC® pipe in lieu of open-cut. After meeting Underground Solutions’ construction manager Mike Garrett I began to trust that the company not only had a superior product but also the experience to support it in the field. The knowledge and experience of the field support personnel on the project was impressive from beginning to end.”Scanlan further commented: “In addition to the hard-cost savings, sliplining generated additional benefits taking into account the reduced public inconvenience and the lower environmental impact compared with open-cut. The reduced trucking for the import/export of excavated material and the lower paving requirements were big benefits.”
Garrett White of Dudek added: “We have worked with Fusible PVC® pipe on several projects now. On this project we used the product to not only perform a quick installation but also to minimize pavement repair and traffic control.”
|Pipeline Details and Project Summary|
|Project:||Jimmy Durante Boulevard|
|Location:||Del Mar, CA|
|Pipe Size:||12-inch DR18, 235 psi|
|Installation:||Slipline into 20-inch steel|
|Owner:||City of Del Mar|
|Design Engineer:||Nasland Engineering|
|Contractor:||PAL General Engineering|