Glossary of Piledriving and Foundation Construction Terms
Welcome to the APE Gloassary for piledriving and foundation construction terms. This is a great place to look for terms that you may be unfamiliar with when working with or researching piledriving technologies. This glossary also contains terms unrelated to piledriving, but that are frequently used on and around foundation construction projects. If you have a question or have term that you would like to add and do not know who to call please contact the APE Headquarters in Washington at (800) 248-8498. Business hours are from 8:00 AM to 5:00 PM Pacific Time. For less immediate inquiries, or if you would like an APE sales representitive to get in contact with you, please visit the APE Contact Request Form.
| TERMS | DEFINITIONS |
| Observation Well | A perforated pipe installed in the ground for monitoring groundwater level. |
| Offshore Lead | A pile hammer lead which has an upper section wherein the hammer is contained and a lower section which closely fits about and guides the pile. The hammer is supported and aligned by the pile after engagement. The pile is usually supported by a template. Also called Cage, Can Lead, Chuch Lead, Rope, Suspended Lead, Pipe Lead. |
| Oil Reservoir | A part in single-acting hammers which over the valve and holds oil to lubricate the valve. The same as the valve cover in double-acting mechanical-valve hammers. |
| Oiler | 1. A device for injecting oil in air or steam lines; also called Lubricator. 2. Assistant equipment operator. |
| On Grade | Placed directly on the ground, or leveled or excavated to the proper elevation. |
| Orange Peel Dredge | A dredge with a bucket or auger that looks like an unbroken orange peel curled up. |
| Order Lengths | Lengths of pile expected for the project, ordered by either the owner, the A/E or contractor from the supplier. |
| Oslo Point | A 3 to 5 in. shaft of hard steel is set into the lower end of an H-pile by slitting the shaft or cutting the web of the pile for some distance, and then welding the shaft to the H-pile. Utilized to secure a toe hold in sloping rock. Can also be fitted to end plate of a pipe pile. |
| Overdriving | 1. Driving that exceeds the maximum warranted hammer blow count or damages the material comprising the pile. 2. Hitting the pile more than the optimum or required number of blows per increment of advance. 3. Continuing to drive after penetration of the pile is stopped. |
| Overhead Leads | See Leads, Extended. |
