A Fitting .... Situation | Cast-In-Place Concrete Access Structures or Junction Chambers?? Hmm...
When faced with designing culverts, storm sewers, or underground detention systems, one of the critical decisions you’ll make as the Engineer of Record is pipe selection. Corrugated Metal Pipe (CMP) is often the go-to solution for stormwater applications, and for good reason. CMP stands out as one of the most versatile pipe products on the market, offering a wide range of sizes, materials, gages, corrugations, and coatings to suit various project requirements. It combines high structural capacity, cost-effectiveness, and ease of installation. But perhaps the most valuable attribute of CMP is its ability to accommodate custom fittings designed to meet the unique challenges of any project.
Whether it’s elbows, tees, wyes, crosses, or bulkheads, CMP fittings are commonly used in storm drain applications. On large sites, as pipe diameters increase and pipe systems converge, engineers often default to cast-in-place concrete structures to provide manhole access for inspection and maintenance. While this is a traditional choice, it’s not always the best solution.
Large precast or cast-in-place concrete structures take considerable time to design, form, and construct. They can also be very expensive. Fortunately, there’s a better, faster, and more cost-effective solution—Corrugated Metal Pipe fittings.
Why Choose CMP Fittings?
CMP fittings can be custom fabricated to suit almost any project need, offering flexibility that concrete structures simply cannot match. These fittings are not only easy to install, but also significantly reduce both material costs and construction time. And when it comes to reinforcing fittings, CMP has you covered.
For example, reinforcement for CMP fittings—when required—should follow ASTM A998, *Standard Practice for Structural Design of Reinforcements for Fittings in Factory-Made Corrugated Steel Pipe for Sewers and Other Applications*. In a recent project, the contractor chose to encase the entire CMP fitting in Controlled Low-Strength Material (CLSM) to provide additional support. This required multiple concrete lifts, but the use of CMP dramatically streamlined the process, from design to installation. Detailed CAD drawings were developed for approval, ensuring that the fitting was perfectly fabricated to meet field conditions.
Cost-Effective and Timesaving
Corrugated Metal Pipe fittings offer significant advantages over traditional concrete structures, especially for large stormwater systems. Faster to fabricate, easier to install, and more adaptable to on-site conditions, CMP is the practical solution for stormwater infrastructure.
Let us help you streamline your next storm sewer projects with custom CMP fittings designed to fit your specific needs. Contact us to explore how CMP can support your designs.