Static pipe bursting consists of constructing a pit, feeding rods through the entire length of existing pipe, latching on to it at the other end, and pulling back the new pipe. The existing pipe is “bursted” in place by a bursting head attached to the front of the new pipe, displacing the fragments into the surrounding soil. For this project we pipe burst 4,675 LF of existing 10” ductile iron force main with 10” fusible HDPE (high density polyethylene). Ductile iron presents challenges as the old pipe must be split as the new pipe is brought through, rather than pipe such as vitrified clay, cast iron, and thinner classes of PVC which fracture easily under pressure. Taking this force main out of service meant we needed to pump sewage into large storage tanks and use tanker trucks to transport the sewage to the treatment plant.
This project called for 1,515 LF of 15-18” vitrified clay pipe (VCP) to be installed via pilot tube micro-tunneling (PTMT) and was a featured project in Trenchless World magazine. The 1,515 LF was installed in six separate drives, the longest of which was a 330 LF shot that crossed under a major freeway (IH 43/894). Trenchless methods were the only ones considered in order to limit traffic disruption on such a popular and congested route. PTMT was the right choice in order to maintain an accurate installation to the desired grade, and to ensure the avoidance of nearby utilities. To learn more about the process and view the article featured in Trenchless World magazine, please click on the PDF file found below.