About the research
Alternatives to driving H-piles are being utilized by a number of states and private industry. Helical/screw pilings are used, and the load bearings are listed as 5 to 50 tons per piling. Micropiles are also used with bearing capacities of 4 to 101+ tons typical per piling. Either of these two options can offer a cost-effective and/or quick construction alternative to driving H-piles.
In addition to helical pilings and micropiles, other regularly used alternative piling systems include grouted helical pilings, ductile iron pilings, drilled displacement pilings, and geopier foundations. A study of their cost-effectiveness and application was the first/main objective of this project.
There is also a need to utilize safe, cost-effective pile driving systems to reconstruct or repair bridges, especially those for low-volume roads. Vibratory pile driving is a method to accomplish this goal.
There is limited data available for tests on the strength of alternative piles or vibratory-driven piles. The second objective of this project was to study the strength and bearing resistance of alternative piles as well as pilings driven with vibratory equipment. This project documented design guidance, construction methods, and acceptance criteria for using alternative abutment piling systems for local roads.
This study included a survey of county engineers in Iowa and of industry engineers in many states.