S-90 Hydrohammer proves ideal on pipe ramming tunnel project
James W. Fowler Co. has selected IHC IQIP’s S-90 Hydrohammer to help install a 12ft-wide (3.6m) tunnel in Portland, Oregon USA. The project is being overseen by the general contractor, Hoffman Construction Company, and will allow pedestrians to move from a new car park to a research building at the Oregon Health & Science University.
The Hydrohammer – with a P-250 power pack and 24” (610mm) guide sleeve – is highly suitable on such a project where space is tight. It is taking place in a cofferdam, which was first excavated and reinforced by the general contractor. James W. Fowler Co. chose the Hydrohammer due to its compact footprint – ideal for confined spaces – and efficient transfer of energy from the hammer through an adaptor cone to the pipe.
Due to the small sleeve, less energy was needed to move the anvil, with most instead being transferred directly through the cone. Cables were hooked alongside the hammer and to the cofferdam walls adjacent to the tunnel. As the piping sections were rammed, the hammer was tensioned and retained against the pipe to maintain constant piling pressure. The process was repeated for each new 10ft (3m) section.
As the project was being completed underneath an existing road and metro track, James W. Fowler Co. opted to drive the tunnel to remove the risk of cave-ins. In addition, the Hydrohammer further condenses and compacts the surrounding soil after each impact. It has a maximum energy blow of 66,380ft-lb (90kNm) despite being only 26ft (8m) in length. An IQIP representative was also on site to assist with setting up the equipment and offer operational know-how.
The project continues the close cooperation between James W. Fowler Co. and IHC IQIP, which again demonstrated the reliability of its equipment and expertise. “The project was successfully completed on time without any delays,” says IHC IQIP Area Manager Andrew Evans. “Our contractor only heard great things from their customer, which is fantastic. Ultimately, we aim to make our customers look good and build track records with them. This development was no exception.”
James W. Fowler Co. was also delighted with the seamless way in which the project unfolded. “We were eager to use the S-90 Hydrohammer not only for its efficiency, but based on our positive experiences with IQIP equipment in the past,” says Larue Nolen, James W. Fowler Co. Project Superintendent. “IQIP is also one of few companies with the capabilities and expertise to perform horizontal driving, which was vital to avoid any structural issues. We will certainly work with them again in the future.”