Large Steel Water Main Project Pushes Static Bursting Envelope

October 2009 Vol. 64 No. 10
The total length of the bursting project was 2,529 feet. The water main ran under a highly traveled roadway in Colorado Springs.

Milestone project
The 24 inch diameter steel pipe represents one of the largest steel pipe bursting projects ever attempted and a significant milestone for static pipe bursting. For the project, Global Underground utilized a Grundoburst 2500G static pipe bursting system from trenchless equipment manufacturer TT Technologies, Aurora, IL. The unit is the largest static pipebursting machine in the world, delivering up to 625,000 pounds of pulling force.

Global Underground is an industry leader in underground utility installation, utilizing horizontal directional drilling, pipe bursting, open excavation and hydro excavation methods. The company was started in 1999 and boasts a skilled staff with over 100 years of combined experience installing utilities. Meadows said, “We do everything water, sewer, gas, electric, petroleum, fiber optics, on grade sewer, etc.”

Meadows described their primary business as unconventional utility construction. That includes hydro excavation, sliplining, pipebursting and HDD. The company has 11 directional drills ranging in size from 7,000 to 440,000-pounds of pullback, and have completed pipebursting projects from four to 26- inches in diameter

Static bursting matures
In order to take on a project of this size in a high traffic area, Meadows decided on a method that is growing in use and popularity. According to TT Technologies pipebursting specialist Dave Holcomb, the static pipe bursting method has come a long way since its inception.

“We’ve seen the static pipe bursting process continue to gain momentum in the industry – it’s matured,” Holcomb observed. “It’s become more versatile now that great progress has been made in using various product pipe materials such as ductile iron, fusible PVC, HDPE and clay. But, as this project in Colorado Springs demonstrates, the capability of the method to take on difficult host pipe materials is also a reason that static pipebursting has become a sought after rehab and replacement method.”

Several things contribute to the effectiveness of the method. Specially designed bladed rollers are one important component. The bladed rollers are pulled through the host pipe by a hydraulically-powered bursting unit. As they are pulled through, they split the host pipe. An expander attached to the rollers forces the fragmented pipe into the surrounding soil while simultaneously pulling in the new pipe.