- ENGINEERING INFO
- CASE STUDIES
In March 2011 Underground Solutions, Inc. contracted with Ghilotti Construction of Santa Rosa, CA to provide Fusible C-905® pipe for the Napa State Hospital Reuse project. The scope included carrier pipe for the critical jack-and-bore crossing of Highway 221 as well as for the open-cut restrained sections. Fusible C-905® was specified by Brown and Caldwell and the District as an option to conventional 24" bell and spigot PVC pipe with metallic bell harness restraints that would also require individual cathodic protection (84 - 17 lb. magnesium anodes in total). The choice to utilize Fusible C-905® provided more than $70,000 in savings to all three low bid contractors. In fact, the bidding was so competitive there was less than 1% between the first two low bidders having submitted bid values greater than $2,000,000. If the low bidding contractor did not select Fusible C-905® they would not have been the low bidder.
The jack-and-bore costs with the Fusible C905® option were effective in driving down bid prices (see Figure 1 for dimensional detail). This three hundred foot (300') section of pipeline provided approximately $50,000 in savings compared with other design options.
Additionally, Fusible C-905® provided a more cost effective thermoplastic restraining solution in the open-cut portions of the project. Conventional mechanical restraint systems only prevent axial pull-out whereas Fusible C-905® provides axial restraint while eliminating long term aging effects from differential settlement and deflection often experienced with conventional segmented pipe systems. Because the Fusible C-905® pipe joint exhibits relative pipe barrel strength, it does not suffer from over insertion, settlement or over deflection which can lead to early pipeline failure. This combination of over insertion, over deflection or settlement of pressure pipes has been well documented to be one of the life limiting factors of bell and spigot pipe.1 The Fusible PVC® fused joint is the only PVC restrained joint in the industry that provides the full performance capacity of the pipe. These performance attributes eliminate or reduce many of the life cycle issues and on-going maintenance costs to maintain mechanically restrained conventional pipe systems with cathodic protection.
|Pipeline Details and Project Summary|
|Project:||Napa State Hospital Reclaim Transmission Line|
|Lenght:||6,000' - J&B (300'), Restrained Open-Cut (2,000') and Open- Cut (3,700')|
|Owner:||Napa Sanitation District|
|Engineer:||Brown and Caldwell, Walnut Creek|
|Contractor:||Ghilotti Construction Construction Management - Covello Group, Walnut Creek, CA|
Andrew Damron with Napa Sanitation District commented, "Fusible PVC® is a cost-effective alternative to conventional bell and spigot restrained pipe."
Brown and Caldwell's Project Manager Pete Bellows stated, "Fusible PVC® provides a solution to mitigate thrust forces generated while lowering the life cycle costs compared with conventional restraint systems."
1. Folkman, et al. "Analytical Model of Stresses Caused by Over-Belling PVC Pipe," Utah State University.